From e11df7c49a8bfc68f411b0013f43112961af449f Mon Sep 17 00:00:00 2001
From: Anton-4 <17049058+Anton-4@users.noreply.github.com>
Date: Sat, 6 Mar 2021 12:14:55 +0100
Subject: [PATCH 01/74] Updated Cargo.lock using

---
 Cargo.lock | 437 ++++++++++++++++++++++++++++-------------------------
 1 file changed, 229 insertions(+), 208 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index ef8b47a77e..e6ddba9981 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -2,9 +2,9 @@
 # It is not intended for manual editing.
 [[package]]
 name = "ab_glyph"
-version = "0.2.9"
+version = "0.2.10"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "65b1f87418ab9d7e1ee2a783aa167767ebeb316d0a9fb10c347aec28a5008acb"
+checksum = "7a933731feda8b460bdad9a9e43bb386baba6ec593d2bc19716ef3c75c09085c"
 dependencies = [
  "ab_glyph_rasterizer",
  "owned_ttf_parser",
@@ -27,9 +27,9 @@ dependencies = [
 
 [[package]]
 name = "adler"
-version = "0.2.3"
+version = "1.0.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ee2a4ec343196209d6594e19543ae87a39f96d5534d7174822a3ad825dd6ed7e"
+checksum = "f26201604c87b1e01bd3d98f8d5d9a8fcbb815e8cedb41ffccbeb4bf593a35fe"
 
 [[package]]
 name = "aho-corasick"
@@ -115,7 +115,7 @@ version = "0.31.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "c69a8137596e84c22d57f3da1b5de1d4230b1742a710091c85f4d7ce50f00f38"
 dependencies = [
- "libloading",
+ "libloading 0.6.7",
 ]
 
 [[package]]
@@ -226,9 +226,9 @@ dependencies = [
 
 [[package]]
 name = "bumpalo"
-version = "3.6.0"
+version = "3.6.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "099e596ef14349721d9016f6b80dd3419ea1bf289ab9b44df8e4dfd3a005d5d9"
+checksum = "63396b8a4b9de3f4fdfb320ab6080762242f66a8ef174c49d8e19b674db4cdbe"
 
 [[package]]
 name = "byte-tools"
@@ -238,9 +238,9 @@ checksum = "e3b5ca7a04898ad4bcd41c90c5285445ff5b791899bb1b0abdd2a2aa791211d7"
 
 [[package]]
 name = "bytemuck"
-version = "1.5.0"
+version = "1.5.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5a4bad0c5981acc24bc09e532f35160f952e35422603f0563cd7a73c2c2e65a0"
+checksum = "bed57e2090563b83ba8f83366628ce535a7584c9afa4c9fc0612a03925c6df58"
 dependencies = [
  "bytemuck_derive",
 ]
@@ -252,8 +252,8 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "8e215f8c2f9f79cb53c8335e687ffd07d5bfcb6fe5fc80723762d0be46e7cc54"
 dependencies = [
  "proc-macro2 1.0.24",
- "quote 1.0.8",
- "syn 1.0.60",
+ "quote 1.0.9",
+ "syn 1.0.61",
 ]
 
 [[package]]
@@ -290,9 +290,9 @@ dependencies = [
 
 [[package]]
 name = "cc"
-version = "1.0.66"
+version = "1.0.67"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4c0496836a84f8d0495758516b8621a622beb77c0fed418570e50764093ced48"
+checksum = "e3c69b077ad434294d3ce9f1f6143a2a4b89a8a2d54ef813d85003a4fd1137fd"
 dependencies = [
  "jobserver",
 ]
@@ -356,8 +356,8 @@ dependencies = [
  "heck",
  "proc-macro-error",
  "proc-macro2 1.0.24",
- "quote 1.0.8",
- "syn 1.0.60",
+ "quote 1.0.9",
+ "syn 1.0.61",
 ]
 
 [[package]]
@@ -420,12 +420,6 @@ dependencies = [
  "winapi 0.3.9",
 ]
 
-[[package]]
-name = "const_fn"
-version = "0.4.5"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "28b9d6de7f49e22cf97ad17fc4036ece69300032f45f78f30b4a4482cdc3f4a6"
-
 [[package]]
 name = "const_format"
 version = "0.2.13"
@@ -442,7 +436,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "8df496e1bbc93814d728a8036ff054cd95830afe9cf2275c9326688c02eff936"
 dependencies = [
  "proc-macro2 1.0.24",
- "quote 1.0.8",
+ "quote 1.0.9",
  "unicode-xid 0.2.1",
 ]
 
@@ -611,7 +605,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "dca26ee1f8d361640700bde38b2c37d8c22b3ce2d360e1fc1c74ea4b0aa7d775"
 dependencies = [
  "cfg-if 1.0.0",
- "crossbeam-utils 0.8.1",
+ "crossbeam-utils 0.8.3",
 ]
 
 [[package]]
@@ -632,8 +626,8 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "94af6efb46fef72616855b036a624cf27ba656ffc9be1b9a3c931cfc7749a9a9"
 dependencies = [
  "cfg-if 1.0.0",
- "crossbeam-epoch 0.9.1",
- "crossbeam-utils 0.8.1",
+ "crossbeam-epoch 0.9.3",
+ "crossbeam-utils 0.8.3",
 ]
 
 [[package]]
@@ -653,13 +647,12 @@ dependencies = [
 
 [[package]]
 name = "crossbeam-epoch"
-version = "0.9.1"
+version = "0.9.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a1aaa739f95311c2c7887a76863f500026092fb1dce0161dab577e559ef3569d"
+checksum = "2584f639eb95fea8c798496315b297cf81b9b58b6d30ab066a75455333cf4b12"
 dependencies = [
  "cfg-if 1.0.0",
- "const_fn",
- "crossbeam-utils 0.8.1",
+ "crossbeam-utils 0.8.3",
  "lazy_static",
  "memoffset 0.6.1",
  "scopeguard",
@@ -689,9 +682,9 @@ dependencies = [
 
 [[package]]
 name = "crossbeam-utils"
-version = "0.8.1"
+version = "0.8.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "02d96d1e189ef58269ebe5b97953da3274d83a93af647c2ddd6f9dab28cedb8d"
+checksum = "e7e9d99fa91428effe99c5c6d4634cdeba32b8cf784fc428a2a687f61a952c49"
 dependencies = [
  "autocfg 1.0.1",
  "cfg-if 1.0.0",
@@ -727,7 +720,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "d0a60cceb22c7c53035f8980524fdc7f17cf49681a3c154e6757d30afbec6ec4"
 dependencies = [
  "bitflags",
- "libloading",
+ "libloading 0.6.7",
  "winapi 0.3.9",
 ]
 
@@ -738,8 +731,8 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "fcc3dd5e9e9c0b295d6e1e4d811fb6f157d5ffd784b8d202fc62eac8035a770b"
 dependencies = [
  "proc-macro2 1.0.24",
- "quote 1.0.8",
- "syn 1.0.60",
+ "quote 1.0.9",
+ "syn 1.0.61",
 ]
 
 [[package]]
@@ -796,7 +789,16 @@ version = "0.4.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "b11f15d1e3268f140f68d390637d5e76d849782d971ae7063e0da69fe9709a76"
 dependencies = [
- "libloading",
+ "libloading 0.6.7",
+]
+
+[[package]]
+name = "dlib"
+version = "0.5.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ac1b7517328c04c2aa68422fc60a41b92208182142ed04a25879c26c8f878794"
+dependencies = [
+ "libloading 0.7.0",
 ]
 
 [[package]]
@@ -950,9 +952,9 @@ checksum = "3dcaa9ae7725d12cdb85b3ad99a434db70b468c09ded17e012d86b5c1010f7a7"
 
 [[package]]
 name = "futures"
-version = "0.3.12"
+version = "0.3.13"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "da9052a1a50244d8d5aa9bf55cbc2fb6f357c86cc52e46c62ed390a7180cf150"
+checksum = "7f55667319111d593ba876406af7c409c0ebb44dc4be6132a783ccf163ea14c1"
 dependencies = [
  "futures-channel",
  "futures-core",
@@ -965,9 +967,9 @@ dependencies = [
 
 [[package]]
 name = "futures-channel"
-version = "0.3.12"
+version = "0.3.13"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f2d31b7ec7efab6eefc7c57233bb10b847986139d88cc2f5a02a1ae6871a1846"
+checksum = "8c2dd2df839b57db9ab69c2c9d8f3e8c81984781937fe2807dc6dcf3b2ad2939"
 dependencies = [
  "futures-core",
  "futures-sink",
@@ -975,15 +977,15 @@ dependencies = [
 
 [[package]]
 name = "futures-core"
-version = "0.3.12"
+version = "0.3.13"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "79e5145dde8da7d1b3892dad07a9c98fc04bc39892b1ecc9692cf53e2b780a65"
+checksum = "15496a72fabf0e62bdc3df11a59a3787429221dd0710ba8ef163d6f7a9112c94"
 
 [[package]]
 name = "futures-executor"
-version = "0.3.12"
+version = "0.3.13"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e9e59fdc009a4b3096bf94f740a0f2424c082521f20a9b08c5c07c48d90fd9b9"
+checksum = "891a4b7b96d84d5940084b2a37632dd65deeae662c114ceaa2c879629c9c0ad1"
 dependencies = [
  "futures-core",
  "futures-task",
@@ -992,42 +994,39 @@ dependencies = [
 
 [[package]]
 name = "futures-io"
-version = "0.3.12"
+version = "0.3.13"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "28be053525281ad8259d47e4de5de657b25e7bac113458555bb4b70bc6870500"
+checksum = "d71c2c65c57704c32f5241c1223167c2c3294fd34ac020c807ddbe6db287ba59"
 
 [[package]]
 name = "futures-macro"
-version = "0.3.12"
+version = "0.3.13"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c287d25add322d9f9abdcdc5927ca398917996600182178774032e9f8258fedd"
+checksum = "ea405816a5139fb39af82c2beb921d52143f556038378d6db21183a5c37fbfb7"
 dependencies = [
  "proc-macro-hack",
  "proc-macro2 1.0.24",
- "quote 1.0.8",
- "syn 1.0.60",
+ "quote 1.0.9",
+ "syn 1.0.61",
 ]
 
 [[package]]
 name = "futures-sink"
-version = "0.3.12"
+version = "0.3.13"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "caf5c69029bda2e743fddd0582d1083951d65cc9539aebf8812f36c3491342d6"
+checksum = "85754d98985841b7d4f5e8e6fbfa4a4ac847916893ec511a2917ccd8525b8bb3"
 
 [[package]]
 name = "futures-task"
-version = "0.3.12"
+version = "0.3.13"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "13de07eb8ea81ae445aca7b69f5f7bf15d7bf4912d8ca37d6645c77ae8a58d86"
-dependencies = [
- "once_cell",
-]
+checksum = "fa189ef211c15ee602667a6fcfe1c1fd9e07d42250d2156382820fba33c9df80"
 
 [[package]]
 name = "futures-util"
-version = "0.3.12"
+version = "0.3.13"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "632a8cd0f2a4b3fdea1657f08bde063848c3bd00f9bbf6e256b8be78802e624b"
+checksum = "1812c7ab8aedf8d6f2701a43e1243acdbcc2b36ab26e2ad421eb99ac963d96d1"
 dependencies = [
  "futures-channel",
  "futures-core",
@@ -1036,7 +1035,7 @@ dependencies = [
  "futures-sink",
  "futures-task",
  "memchr",
- "pin-project-lite 0.2.4",
+ "pin-project-lite 0.2.6",
  "pin-utils",
  "proc-macro-hack",
  "proc-macro-nested",
@@ -1054,9 +1053,9 @@ dependencies = [
 
 [[package]]
 name = "generic-array"
-version = "0.12.3"
+version = "0.12.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c68f0274ae0e023facc3c97b2e00f076be70e254bc851d972503b328db79b2ec"
+checksum = "ffdf9f34f1447443d37393cc6c2b8313aebddcd96906caf34e54c68d8e57d7bd"
 dependencies = [
  "typenum",
 ]
@@ -1104,7 +1103,7 @@ dependencies = [
  "bitflags",
  "gfx-auxil",
  "gfx-hal",
- "libloading",
+ "libloading 0.6.7",
  "log",
  "parking_lot 0.11.1",
  "range-alloc",
@@ -1282,9 +1281,9 @@ checksum = "62aca2aba2d62b4a7f5b33f3712cb1b0692779a56fb510499d5c0aa594daeaf3"
 
 [[package]]
 name = "handlebars"
-version = "3.5.2"
+version = "3.5.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "964d0e99a61fe9b1b347389b77ebf8b7e1587b70293676aaca7d27e59b9073b2"
+checksum = "cdb0867bbc5a3da37a753e78021d5fcf8a4db00e18dd2dd90fd36e24190e162d"
 dependencies = [
  "log",
  "pest",
@@ -1357,9 +1356,9 @@ dependencies = [
 
 [[package]]
 name = "indexmap"
-version = "1.6.1"
+version = "1.6.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4fb1fa934250de4de8aef298d81c729a7d33d8c239daa3a7575e6b92bfc7313b"
+checksum = "824845a0bf897a9042383849b02c1bc219c2383772efcd5c6f9766fa4b81aef3"
 dependencies = [
  "autocfg 1.0.1",
  "hashbrown",
@@ -1383,8 +1382,8 @@ checksum = "ce046d161f000fffde5f432a0d034d0341dc152643b2598ed5bfce44c4f3a8f0"
 dependencies = [
  "proc-macro-hack",
  "proc-macro2 1.0.24",
- "quote 1.0.8",
- "syn 1.0.60",
+ "quote 1.0.9",
+ "syn 1.0.61",
  "unindent",
 ]
 
@@ -1408,8 +1407,8 @@ version = "0.2.0"
 source = "git+https://github.com/rtfeldman/inkwell?tag=llvm10-0.release3#57e9f00d98fc99486e737c314e56a59498c5dbbb"
 dependencies = [
  "proc-macro2 1.0.24",
- "quote 1.0.8",
- "syn 1.0.60",
+ "quote 1.0.9",
+ "syn 1.0.61",
 ]
 
 [[package]]
@@ -1483,9 +1482,9 @@ dependencies = [
 
 [[package]]
 name = "js-sys"
-version = "0.3.47"
+version = "0.3.48"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5cfb73131c35423a367daf8cbd24100af0d077668c8c2943f0e7dd775fef0f65"
+checksum = "dc9f84f9b115ce7843d60706df1422a916680bfdfcbdb0447c5614ff9d7e4d78"
 dependencies = [
  "wasm-bindgen",
 ]
@@ -1520,9 +1519,9 @@ checksum = "830d08ce1d1d941e6b30645f1a0eb5643013d835ce3779a5fc208261dbe10f55"
 
 [[package]]
 name = "libc"
-version = "0.2.85"
+version = "0.2.88"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7ccac4b00700875e6a07c6cde370d44d32fa01c5a65cdd2fca6858c479d28bb3"
+checksum = "03b07a082330a35e43f63177cc01689da34fbffa0105e1246cf0311472cac73a"
 
 [[package]]
 name = "libloading"
@@ -1534,6 +1533,16 @@ dependencies = [
  "winapi 0.3.9",
 ]
 
+[[package]]
+name = "libloading"
+version = "0.7.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6f84d96438c15fcd6c3f244c8fce01d1e2b9c6b5623e9c711dc9286d8fc92d6a"
+dependencies = [
+ "cfg-if 1.0.0",
+ "winapi 0.3.9",
+]
+
 [[package]]
 name = "line_drawing"
 version = "0.7.0"
@@ -1551,9 +1560,9 @@ checksum = "7fb9b38af92608140b86b693604b9ffcc5824240a484d1ecd4795bacb2fe88f3"
 
 [[package]]
 name = "llvm-sys"
-version = "100.2.0"
+version = "100.2.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9109e19fbfac3458f2970189719fa19f1007c6fd4e08c44fdebf4be0ddbe261d"
+checksum = "15d9c00ce56221b2150e2d4d51887ff139fce5a0e50346c744861d1e66d2f7c4"
 dependencies = [
  "cc",
  "lazy_static",
@@ -1669,9 +1678,9 @@ dependencies = [
 
 [[package]]
 name = "miniz_oxide"
-version = "0.4.3"
+version = "0.4.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0f2d26ec3309788e423cfbf68ad1800f061638098d76a83681af979dc4eda19d"
+checksum = "a92518e98c078586bc6c934028adcca4c92a53d6a958196de835170a01d84e4b"
 dependencies = [
  "adler",
  "autocfg 1.0.1",
@@ -1814,10 +1823,22 @@ dependencies = [
 ]
 
 [[package]]
-name = "nom"
-version = "6.1.0"
+name = "nix"
+version = "0.20.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ab6f70b46d6325aa300f1c7bb3d470127dfc27806d8ea6bf294ee0ce643ce2b1"
+checksum = "fa9b4819da1bc61c0ea48b63b7bc8604064dd43013e7cc325df098d49cd7c18a"
+dependencies = [
+ "bitflags",
+ "cc",
+ "cfg-if 1.0.0",
+ "libc",
+]
+
+[[package]]
+name = "nom"
+version = "6.1.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e7413f999671bd4745a7b624bd370a569fb6bc574b23c83a3c5ed2e453f3d5e2"
 dependencies = [
  "memchr",
  "version_check",
@@ -1860,8 +1881,8 @@ checksum = "ffa5a33ddddfee04c0283a7653987d634e880347e96b5b2ed64de07efb59db9d"
 dependencies = [
  "proc-macro-crate",
  "proc-macro2 1.0.24",
- "quote 1.0.8",
- "syn 1.0.60",
+ "quote 1.0.9",
+ "syn 1.0.61",
 ]
 
 [[package]]
@@ -1923,9 +1944,9 @@ checksum = "a9a7ab5d64814df0fe4a4b5ead45ed6c5f181ee3ff04ba344313a6c80446c5d4"
 
 [[package]]
 name = "once_cell"
-version = "1.5.2"
+version = "1.7.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "13bd41f508810a131401606d54ac32a467c97172d74ba7662562ebba5ad07fa0"
+checksum = "af8b08b04175473088b46763e51ee54da5f9a164bc162f615b91bc179dbf15a3"
 
 [[package]]
 name = "oorandom"
@@ -1959,9 +1980,9 @@ dependencies = [
 
 [[package]]
 name = "owned_ttf_parser"
-version = "0.11.0"
+version = "0.12.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "948b27637ba56144c62d3415929ef18986b3a383137ebcbe97d9362a968bf997"
+checksum = "3a3c7a20e3f122223e68eef6ca58e39bc1ea8a1d83418ba4c2c1ba189d2ee355"
 dependencies = [
  "ttf-parser",
 ]
@@ -1996,8 +2017,8 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "0b4b5f600e60dd3a147fb57b4547033d382d1979eb087af310e91cb45a63b1f4"
 dependencies = [
  "proc-macro2 1.0.24",
- "quote 1.0.8",
- "syn 1.0.60",
+ "quote 1.0.9",
+ "syn 1.0.61",
 ]
 
 [[package]]
@@ -2018,7 +2039,7 @@ checksum = "6d7744ac029df22dca6284efe4e898991d28e3085c706c972bcd7da4a27a15eb"
 dependencies = [
  "instant",
  "lock_api 0.4.2",
- "parking_lot_core 0.8.2",
+ "parking_lot_core 0.8.3",
 ]
 
 [[package]]
@@ -2037,16 +2058,16 @@ dependencies = [
 
 [[package]]
 name = "parking_lot_core"
-version = "0.8.2"
+version = "0.8.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9ccb628cad4f84851442432c60ad8e1f607e29752d0bf072cbd0baf28aa34272"
+checksum = "fa7a782938e745763fe6907fc6ba86946d72f49fe7e21de074e08128a99fb018"
 dependencies = [
  "backtrace",
  "cfg-if 1.0.0",
  "instant",
  "libc",
  "petgraph",
- "redox_syscall 0.1.57",
+ "redox_syscall 0.2.5",
  "smallvec",
  "thread-id",
  "winapi 0.3.9",
@@ -2086,8 +2107,8 @@ dependencies = [
  "pest",
  "pest_meta",
  "proc-macro2 1.0.24",
- "quote 1.0.8",
- "syn 1.0.60",
+ "quote 1.0.9",
+ "syn 1.0.61",
 ]
 
 [[package]]
@@ -2151,15 +2172,15 @@ dependencies = [
 
 [[package]]
 name = "pin-project-lite"
-version = "0.1.11"
+version = "0.1.12"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c917123afa01924fc84bb20c4c03f004d9c38e5127e3c039bbf7f4b9c76a2f6b"
+checksum = "257b64915a082f7811703966789728173279bdebb956b143dbcd23f6f970a777"
 
 [[package]]
 name = "pin-project-lite"
-version = "0.2.4"
+version = "0.2.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "439697af366c49a6d0a010c56a0d97685bc140ce0d377b13a2ea2aa42d64a827"
+checksum = "dc0e1f259c92177c30a4c9d177246edd0a3568b25756a977d0632cf8fa37e905"
 
 [[package]]
 name = "pin-utils"
@@ -2234,8 +2255,8 @@ checksum = "18f33027081eba0a6d8aba6d1b1c3a3be58cbb12106341c2d5759fcd9b5277e7"
 dependencies = [
  "proc-macro-error-attr",
  "proc-macro2 1.0.24",
- "quote 1.0.8",
- "syn 1.0.60",
+ "quote 1.0.9",
+ "syn 1.0.61",
  "version_check",
 ]
 
@@ -2246,8 +2267,8 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "8a5b4b77fdb63c1eca72173d68d24501c54ab1269409f6b672c85deb18af69de"
 dependencies = [
  "proc-macro2 1.0.24",
- "quote 1.0.8",
- "syn 1.0.60",
+ "quote 1.0.9",
+ "syn 1.0.61",
  "syn-mid",
  "version_check",
 ]
@@ -2339,9 +2360,9 @@ dependencies = [
 
 [[package]]
 name = "quote"
-version = "1.0.8"
+version = "1.0.9"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "991431c3519a3f36861882da93630ce66b52918dcf1b8e2fd66b397fc96f28df"
+checksum = "c3d0b9745dc2debf507c8422de05d7226cc1f0644216dfdfead988f9b1ab32a7"
 dependencies = [
  "proc-macro2 1.0.24",
 ]
@@ -2387,7 +2408,7 @@ checksum = "0ef9e7e66b4468674bfcb0c81af8b7fa0bb154fa9f28eb840da5c447baeb8d7e"
 dependencies = [
  "libc",
  "rand_chacha 0.3.0",
- "rand_core 0.6.1",
+ "rand_core 0.6.2",
  "rand_hc 0.3.0",
 ]
 
@@ -2418,7 +2439,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "e12735cf05c9e10bf21534da50a147b924d555dc7a547c42e6bb2d5b6017ae0d"
 dependencies = [
  "ppv-lite86",
- "rand_core 0.6.1",
+ "rand_core 0.6.2",
 ]
 
 [[package]]
@@ -2447,9 +2468,9 @@ dependencies = [
 
 [[package]]
 name = "rand_core"
-version = "0.6.1"
+version = "0.6.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c026d7df8b298d90ccbbc5190bd04d85e159eaf5576caeacf8741da93ccbd2e5"
+checksum = "34cf66eb183df1c5876e2dcf6b13d57340741e8dc255b48e40a26de954d06ae7"
 dependencies = [
  "getrandom 0.2.2",
 ]
@@ -2478,7 +2499,7 @@ version = "0.3.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "3190ef7066a446f2e7f42e239d161e905420ccab01eb967c9eb27d21b2322a73"
 dependencies = [
- "rand_core 0.6.1",
+ "rand_core 0.6.2",
 ]
 
 [[package]]
@@ -2587,7 +2608,7 @@ checksum = "9ab346ac5921dc62ffa9f89b7a773907511cdfa5490c572ae9be1be33e8afa4a"
 dependencies = [
  "crossbeam-channel 0.5.0",
  "crossbeam-deque 0.8.0",
- "crossbeam-utils 0.8.1",
+ "crossbeam-utils 0.8.3",
  "lazy_static",
  "num_cpus",
 ]
@@ -2609,9 +2630,9 @@ checksum = "41cc0f7e4d5d4544e8861606a285bb08d3e70712ccc7d2b84d7c0ccfaf4b05ce"
 
 [[package]]
 name = "redox_syscall"
-version = "0.2.4"
+version = "0.2.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "05ec8ca9416c5ea37062b502703cd7fcb207736bc294f6e0cf367ac6fc234570"
+checksum = "94341e4e44e24f6b591b59e47a8a027df12e008d73fd5672dbea9cc22f4507d9"
 dependencies = [
  "bitflags",
 ]
@@ -2623,7 +2644,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "528532f3d801c87aec9def2add9ca802fe569e44a544afe633765267840abe64"
 dependencies = [
  "getrandom 0.2.2",
- "redox_syscall 0.2.4",
+ "redox_syscall 0.2.5",
 ]
 
 [[package]]
@@ -2672,7 +2693,7 @@ dependencies = [
  "indoc",
  "inkwell",
  "inlinable_string",
- "libloading",
+ "libloading 0.6.7",
  "maplit",
  "pretty_assertions",
  "quickcheck",
@@ -2746,7 +2767,7 @@ dependencies = [
  "inkwell",
  "inlinable_string",
  "libc",
- "libloading",
+ "libloading 0.6.7",
  "maplit",
  "pretty_assertions",
  "quickcheck",
@@ -2918,7 +2939,7 @@ dependencies = [
  "inlinable_string",
  "itertools 0.9.0",
  "libc",
- "libloading",
+ "libloading 0.6.7",
  "maplit",
  "object 0.22.0",
  "pretty_assertions",
@@ -3218,8 +3239,8 @@ version = "0.4.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "db9dfbf470021de34cfaf6983067f460ea19164934a7c2d4b92eec0968eb95f1"
 dependencies = [
- "quote 1.0.8",
- "syn 1.0.60",
+ "quote 1.0.9",
+ "syn 1.0.61",
 ]
 
 [[package]]
@@ -3266,9 +3287,9 @@ checksum = "388a1df253eca08550bef6c72392cfe7c30914bf41df5269b68cbd6ff8f570a3"
 
 [[package]]
 name = "serde"
-version = "1.0.123"
+version = "1.0.124"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "92d5161132722baa40d802cc70b15262b98258453e85e5d1d365c757c73869ae"
+checksum = "bd761ff957cb2a45fbb9ab3da6512de9de55872866160b23c25f1a841e99d29f"
 dependencies = [
  "serde_derive",
 ]
@@ -3297,20 +3318,20 @@ dependencies = [
 
 [[package]]
 name = "serde_derive"
-version = "1.0.123"
+version = "1.0.124"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9391c295d64fc0abb2c556bad848f33cb8296276b1ad2677d1ae1ace4f258f31"
+checksum = "1800f7693e94e186f5e25a28291ae1570da908aff7d97a095dec1e56ff99069b"
 dependencies = [
  "proc-macro2 1.0.24",
- "quote 1.0.8",
- "syn 1.0.60",
+ "quote 1.0.9",
+ "syn 1.0.61",
 ]
 
 [[package]]
 name = "serde_json"
-version = "1.0.62"
+version = "1.0.64"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ea1c6153794552ea7cf7cf63b1231a25de00ec90db326ba6264440fa08e31486"
+checksum = "799e97dc9fdae36a5c8b8f2cae9ce2ee9fdce2058c57a93e6099d919fd982f79"
 dependencies = [
  "itoa",
  "ryu",
@@ -3335,8 +3356,8 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "b2acd6defeddb41eb60bb468f8825d0cfd0c2a76bc03bfd235b6a1dc4f6a1ad5"
 dependencies = [
  "proc-macro2 1.0.24",
- "quote 1.0.8",
- "syn 1.0.60",
+ "quote 1.0.9",
+ "syn 1.0.61",
 ]
 
 [[package]]
@@ -3387,7 +3408,7 @@ checksum = "421c8dc7acf5cb205b88160f8b4cc2c5cfabe210e43b2f80f009f4c1ef910f1d"
 dependencies = [
  "andrew",
  "bitflags",
- "dlib",
+ "dlib 0.4.2",
  "lazy_static",
  "memmap",
  "nix 0.14.1",
@@ -3397,19 +3418,19 @@ dependencies = [
 
 [[package]]
 name = "smithay-client-toolkit"
-version = "0.12.2"
+version = "0.12.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "316e13a3eb853ce7bf72ad3530dc186cb2005c57c521ef5f4ada5ee4eed74de6"
+checksum = "4750c76fd5d3ac95fa3ed80fe667d6a3d8590a960e5b575b98eea93339a80b80"
 dependencies = [
  "bitflags",
- "dlib",
+ "dlib 0.4.2",
  "lazy_static",
  "log",
  "memmap2",
  "nix 0.18.0",
- "wayland-client 0.28.3",
+ "wayland-client 0.28.5",
  "wayland-cursor",
- "wayland-protocols 0.28.3",
+ "wayland-protocols 0.28.5",
 ]
 
 [[package]]
@@ -3418,8 +3439,8 @@ version = "0.6.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "06384dfaf645908220d976ae24ed39f6cf92efecb0225ea0a948e403014de527"
 dependencies = [
- "smithay-client-toolkit 0.12.2",
- "wayland-client 0.28.3",
+ "smithay-client-toolkit 0.12.3",
+ "wayland-client 0.28.5",
 ]
 
 [[package]]
@@ -3440,8 +3461,8 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "1508efa03c362e23817f96cde18abed596a25219a8b2c66e8db33c03543d315b"
 dependencies = [
  "proc-macro2 1.0.24",
- "quote 1.0.8",
- "syn 1.0.60",
+ "quote 1.0.9",
+ "syn 1.0.61",
 ]
 
 [[package]]
@@ -3517,12 +3538,12 @@ dependencies = [
 
 [[package]]
 name = "syn"
-version = "1.0.60"
+version = "1.0.61"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c700597eca8a5a762beb35753ef6b94df201c81cca676604f547495a0d7f0081"
+checksum = "ed22b90a0e734a23a7610f4283ac9e5acfb96cbb30dfefa540d66f866f1c09c5"
 dependencies = [
  "proc-macro2 1.0.24",
- "quote 1.0.8",
+ "quote 1.0.9",
  "unicode-xid 0.2.1",
 ]
 
@@ -3533,8 +3554,8 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "baa8e7560a164edb1621a55d18a0c59abf49d360f47aa7b821061dd7eea7fac9"
 dependencies = [
  "proc-macro2 1.0.24",
- "quote 1.0.8",
- "syn 1.0.60",
+ "quote 1.0.9",
+ "syn 1.0.61",
 ]
 
 [[package]]
@@ -3544,8 +3565,8 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "b834f2d66f734cb897113e34aaff2f1ab4719ca946f9a7358dba8f8064148701"
 dependencies = [
  "proc-macro2 1.0.24",
- "quote 1.0.8",
- "syn 1.0.60",
+ "quote 1.0.9",
+ "syn 1.0.61",
  "unicode-xid 0.2.1",
 ]
 
@@ -3564,7 +3585,7 @@ dependencies = [
  "cfg-if 1.0.0",
  "libc",
  "rand 0.8.3",
- "redox_syscall 0.2.4",
+ "redox_syscall 0.2.5",
  "remove_dir_all",
  "winapi 0.3.9",
 ]
@@ -3590,7 +3611,7 @@ dependencies = [
  "inkwell",
  "inlinable_string",
  "libc",
- "libloading",
+ "libloading 0.6.7",
  "maplit",
  "quickcheck",
  "quickcheck_macros",
@@ -3626,22 +3647,22 @@ dependencies = [
 
 [[package]]
 name = "thiserror"
-version = "1.0.23"
+version = "1.0.24"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "76cc616c6abf8c8928e2fdcc0dbfab37175edd8fb49a4641066ad1364fdab146"
+checksum = "e0f4a65597094d4483ddaed134f409b2cb7c1beccf25201a9f73c719254fa98e"
 dependencies = [
  "thiserror-impl",
 ]
 
 [[package]]
 name = "thiserror-impl"
-version = "1.0.23"
+version = "1.0.24"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9be73a2caec27583d0046ef3796c3794f868a5bc813db689eed00c7631275cd1"
+checksum = "7765189610d8241a44529806d6fd1f2e0a08734313a35d5b3a556f92b381f3c0"
 dependencies = [
  "proc-macro2 1.0.24",
- "quote 1.0.8",
- "syn 1.0.60",
+ "quote 1.0.9",
+ "syn 1.0.61",
 ]
 
 [[package]]
@@ -3672,9 +3693,9 @@ checksum = "7572415bd688d401c52f6e36f4c8e805b9ae1622619303b9fa835d531db0acae"
 
 [[package]]
 name = "tinytemplate"
-version = "1.2.0"
+version = "1.2.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a2ada8616fad06a2d0c455adc530de4ef57605a8120cc65da9653e0e9623ca74"
+checksum = "be4d6b5f19ff7664e8c98d03e2139cb510db9b0a60b55f8e8709b689d939b6bc"
 dependencies = [
  "serde",
  "serde_json",
@@ -3690,7 +3711,7 @@ dependencies = [
  "fnv",
  "memchr",
  "num_cpus",
- "pin-project-lite 0.1.11",
+ "pin-project-lite 0.1.12",
  "slab",
 ]
 
@@ -3705,12 +3726,12 @@ dependencies = [
 
 [[package]]
 name = "tracing"
-version = "0.1.23"
+version = "0.1.25"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f7d40a22fd029e33300d8d89a5cc8ffce18bb7c587662f54629e94c9de5487f3"
+checksum = "01ebdc2bb4498ab1ab5f5b73c5803825e60199229ccba0698170e3be0e7f959f"
 dependencies = [
  "cfg-if 1.0.0",
- "pin-project-lite 0.2.4",
+ "pin-project-lite 0.2.6",
  "tracing-core",
 ]
 
@@ -3725,9 +3746,9 @@ dependencies = [
 
 [[package]]
 name = "ttf-parser"
-version = "0.11.0"
+version = "0.12.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f3e7994fc4aed0ee366a4b0d01562c8a7cd5a5017088bceb6921b0c8c538f34e"
+checksum = "85e00391c1f3d171490a3f8bd79999b0002ae38d3da0d6a3a306c754b053d71b"
 
 [[package]]
 name = "twox-hash"
@@ -3887,9 +3908,9 @@ checksum = "fd6fbd9a79829dd1ad0cc20627bf1ed606756a7f77edff7b66b7064f9cb327c6"
 
 [[package]]
 name = "wasm-bindgen"
-version = "0.2.70"
+version = "0.2.71"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "55c0f7123de74f0dab9b7d00fd614e7b19349cd1e2f5252bbe9b1754b59433be"
+checksum = "7ee1280240b7c461d6a0071313e08f34a60b0365f14260362e5a2b17d1d31aa7"
 dependencies = [
  "cfg-if 1.0.0",
  "wasm-bindgen-macro",
@@ -3897,24 +3918,24 @@ dependencies = [
 
 [[package]]
 name = "wasm-bindgen-backend"
-version = "0.2.70"
+version = "0.2.71"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7bc45447f0d4573f3d65720f636bbcc3dd6ce920ed704670118650bcd47764c7"
+checksum = "5b7d8b6942b8bb3a9b0e73fc79b98095a27de6fa247615e59d096754a3bc2aa8"
 dependencies = [
  "bumpalo",
  "lazy_static",
  "log",
  "proc-macro2 1.0.24",
- "quote 1.0.8",
- "syn 1.0.60",
+ "quote 1.0.9",
+ "syn 1.0.61",
  "wasm-bindgen-shared",
 ]
 
 [[package]]
 name = "wasm-bindgen-futures"
-version = "0.4.20"
+version = "0.4.21"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3de431a2910c86679c34283a33f66f4e4abd7e0aec27b6669060148872aadf94"
+checksum = "8e67a5806118af01f0d9045915676b22aaebecf4178ae7021bc171dab0b897ab"
 dependencies = [
  "cfg-if 1.0.0",
  "js-sys",
@@ -3924,32 +3945,32 @@ dependencies = [
 
 [[package]]
 name = "wasm-bindgen-macro"
-version = "0.2.70"
+version = "0.2.71"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3b8853882eef39593ad4174dd26fc9865a64e84026d223f63bb2c42affcbba2c"
+checksum = "e5ac38da8ef716661f0f36c0d8320b89028efe10c7c0afde65baffb496ce0d3b"
 dependencies = [
- "quote 1.0.8",
+ "quote 1.0.9",
  "wasm-bindgen-macro-support",
 ]
 
 [[package]]
 name = "wasm-bindgen-macro-support"
-version = "0.2.70"
+version = "0.2.71"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4133b5e7f2a531fa413b3a1695e925038a05a71cf67e87dafa295cb645a01385"
+checksum = "cc053ec74d454df287b9374ee8abb36ffd5acb95ba87da3ba5b7d3fe20eb401e"
 dependencies = [
  "proc-macro2 1.0.24",
- "quote 1.0.8",
- "syn 1.0.60",
+ "quote 1.0.9",
+ "syn 1.0.61",
  "wasm-bindgen-backend",
  "wasm-bindgen-shared",
 ]
 
 [[package]]
 name = "wasm-bindgen-shared"
-version = "0.2.70"
+version = "0.2.71"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "dd4945e4943ae02d15c13962b38a5b1e81eadd4b71214eee75af64a4d6a4fd64"
+checksum = "7d6f8ec44822dd71f5f221a5847fb34acd9060535c1211b70a05844c0f6383b1"
 
 [[package]]
 name = "wasmparser"
@@ -3976,18 +3997,18 @@ dependencies = [
 
 [[package]]
 name = "wayland-client"
-version = "0.28.3"
+version = "0.28.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "bdbdbe01d03b2267809f3ed99495b37395387fde789e0f2ebb78e8b43f75b6d7"
+checksum = "06ca44d86554b85cf449f1557edc6cc7da935cc748c8e4bf1c507cbd43bae02c"
 dependencies = [
  "bitflags",
  "downcast-rs",
  "libc",
- "nix 0.18.0",
+ "nix 0.20.0",
  "scoped-tls",
- "wayland-commons 0.28.3",
- "wayland-scanner 0.28.3",
- "wayland-sys 0.28.3",
+ "wayland-commons 0.28.5",
+ "wayland-scanner 0.28.5",
+ "wayland-sys 0.28.5",
 ]
 
 [[package]]
@@ -4002,24 +4023,24 @@ dependencies = [
 
 [[package]]
 name = "wayland-commons"
-version = "0.28.3"
+version = "0.28.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "480450f76717edd64ad04a4426280d737fc3d10a236b982df7b1aee19f0e2d56"
+checksum = "8bd75ae380325dbcff2707f0cd9869827ea1d2d6d534cff076858d3f0460fd5a"
 dependencies = [
- "nix 0.18.0",
+ "nix 0.20.0",
  "once_cell",
  "smallvec",
- "wayland-sys 0.28.3",
+ "wayland-sys 0.28.5",
 ]
 
 [[package]]
 name = "wayland-cursor"
-version = "0.28.3"
+version = "0.28.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d6eb122c160223a7660feeaf949d0100281d1279acaaed3720eb3c9894496e5f"
+checksum = "b37e5455ec72f5de555ec39b5c3704036ac07c2ecd50d0bffe02d5fe2d4e65ab"
 dependencies = [
- "nix 0.18.0",
- "wayland-client 0.28.3",
+ "nix 0.20.0",
+ "wayland-client 0.28.5",
  "xcursor",
 ]
 
@@ -4037,14 +4058,14 @@ dependencies = [
 
 [[package]]
 name = "wayland-protocols"
-version = "0.28.3"
+version = "0.28.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "319a82b4d3054dd25acc32d9aee0f84fa95b63bc983fffe4703b6b8d47e01a30"
+checksum = "95df3317872bcf9eec096c864b69aa4769a1d5d6291a5b513f8ba0af0efbd52c"
 dependencies = [
  "bitflags",
- "wayland-client 0.28.3",
- "wayland-commons 0.28.3",
- "wayland-scanner 0.28.3",
+ "wayland-client 0.28.5",
+ "wayland-commons 0.28.5",
+ "wayland-scanner 0.28.5",
 ]
 
 [[package]]
@@ -4060,12 +4081,12 @@ dependencies = [
 
 [[package]]
 name = "wayland-scanner"
-version = "0.28.3"
+version = "0.28.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7010ba5767b3fcd350decc59055390b4ebe6bd1b9279a9feb1f1888987f1133d"
+checksum = "389d680d7bd67512dc9c37f39560224327038deb0f0e8d33f870900441b68720"
 dependencies = [
  "proc-macro2 1.0.24",
- "quote 1.0.8",
+ "quote 1.0.9",
  "xml-rs",
 ]
 
@@ -4075,26 +4096,26 @@ version = "0.23.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "d94e89a86e6d6d7c7c9b19ebf48a03afaac4af6bc22ae570e9a24124b75358f4"
 dependencies = [
- "dlib",
+ "dlib 0.4.2",
  "lazy_static",
 ]
 
 [[package]]
 name = "wayland-sys"
-version = "0.28.3"
+version = "0.28.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6793834e0c35d11fd96a97297abe03d37be627e1847da52e17d7e0e3b51cc099"
+checksum = "2907bd297eef464a95ba9349ea771611771aa285b932526c633dc94d5400a8e2"
 dependencies = [
- "dlib",
+ "dlib 0.5.0",
  "lazy_static",
  "pkg-config",
 ]
 
 [[package]]
 name = "web-sys"
-version = "0.3.47"
+version = "0.3.48"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c40dc691fc48003eba817c38da7113c15698142da971298003cac3ef175680b3"
+checksum = "ec600b26223b2948cedfde2a0aa6756dcf1fef616f43d7b3097aaf53a6c4d92b"
 dependencies = [
  "js-sys",
  "wasm-bindgen",
@@ -4358,6 +4379,6 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "d498dbd1fd7beb83c86709ae1c33ca50942889473473d287d56ce4770a18edfb"
 dependencies = [
  "proc-macro2 1.0.24",
- "syn 1.0.60",
+ "syn 1.0.61",
  "synstructure",
 ]

From 8aa0006e891943a9a806df8a0444cab090690af1 Mon Sep 17 00:00:00 2001
From: Anton-4 <17049058+Anton-4@users.noreply.github.com>
Date: Mon, 8 Mar 2021 12:25:55 +0100
Subject: [PATCH 02/74] done updating editor dependencies to latest version

---
 Cargo.lock                                | 974 ++++++++++++----------
 editor/Cargo.toml                         |  22 +-
 editor/editor-ideas.md                    |   3 +-
 editor/src/editor/main.rs                 |  38 +-
 editor/src/graphics/lowlevel/ortho.rs     |   7 +-
 editor/src/graphics/lowlevel/pipelines.rs |  42 +-
 editor/src/graphics/lowlevel/vertex.rs    |   8 +-
 7 files changed, 588 insertions(+), 506 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index e6ddba9981..2994b76f3a 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -7,7 +7,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "7a933731feda8b460bdad9a9e43bb386baba6ec593d2bc19716ef3c75c09085c"
 dependencies = [
  "ab_glyph_rasterizer",
- "owned_ttf_parser",
+ "owned_ttf_parser 0.12.0",
 ]
 
 [[package]]
@@ -31,6 +31,12 @@ version = "1.0.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "f26201604c87b1e01bd3d98f8d5d9a8fcbb815e8cedb41ffccbeb4bf593a35fe"
 
+[[package]]
+name = "ahash"
+version = "0.4.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "739f4a8db6605981345c5654f3a85b056ce52f37a39d34da03f25bf2151ea16e"
+
 [[package]]
 name = "aho-corasick"
 version = "0.7.15"
@@ -42,24 +48,17 @@ dependencies = [
 
 [[package]]
 name = "andrew"
-version = "0.2.1"
+version = "0.3.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9b7f09f89872c2b6b29e319377b1fbe91c6f5947df19a25596e121cf19a7b35e"
+checksum = "8c4afb09dd642feec8408e33f92f3ffc4052946f6b20f32fb99c1f58cd4fa7cf"
 dependencies = [
  "bitflags",
- "line_drawing",
- "rusttype 0.7.9",
+ "rusttype",
  "walkdir",
  "xdg",
  "xml-rs",
 ]
 
-[[package]]
-name = "android_log-sys"
-version = "0.1.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b8052e2d8aabbb8d556d6abbcce2a22b9590996c5f849b9c7ce4544a2e3b984e"
-
 [[package]]
 name = "ansi_term"
 version = "0.11.0"
@@ -91,7 +90,7 @@ dependencies = [
 name = "arena-pool"
 version = "0.1.0"
 dependencies = [
- "pretty_assertions",
+ "pretty_assertions 0.5.1",
 ]
 
 [[package]]
@@ -270,13 +269,12 @@ checksum = "0e4cec68f03f32e44924783795810fa50a7035d8c8ebe78580ad7e6c703fba38"
 
 [[package]]
 name = "calloop"
-version = "0.4.4"
+version = "0.6.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7aa2097be53a00de9e8fc349fea6d76221f398f5c4fa550d420669906962d160"
+checksum = "0b036167e76041694579972c28cf4877b4f92da222560ddb49008937b6a6727c"
 dependencies = [
- "mio",
- "mio-extras",
- "nix 0.14.1",
+ "log",
+ "nix 0.18.0",
 ]
 
 [[package]]
@@ -310,14 +308,19 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "baf1de4339761588bc0619e3cbc0120ee582ebb74b53b4efbf79117bd2da40fd"
 
 [[package]]
-name = "cgmath"
-version = "0.17.0"
+name = "cfg_aliases"
+version = "0.1.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "283944cdecc44bf0b8dd010ec9af888d3b4f142844fdbe026c20ef68148d6fe7"
+checksum = "fd16c4719339c4530435d38e511904438d07cce7950afa3718a84ac36c10e89e"
+
+[[package]]
+name = "cgmath"
+version = "0.18.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1a98d30140e3296250832bbaaff83b27dcd6fa3cc70fb6f1f3e5c9c0023b5317"
 dependencies = [
- "approx 0.3.2",
+ "approx 0.4.0",
  "num-traits",
- "rand 0.6.5",
 ]
 
 [[package]]
@@ -381,14 +384,15 @@ dependencies = [
 
 [[package]]
 name = "cocoa"
-version = "0.20.2"
+version = "0.24.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0c49e86fc36d5704151f5996b7b3795385f50ce09e3be0f47a0cfde869681cf8"
+checksum = "6f63902e9223530efb4e26ccd0cf55ec30d592d3b42e21a28defc42a9586e832"
 dependencies = [
  "bitflags",
  "block",
- "core-foundation 0.7.0",
- "core-graphics",
+ "cocoa-foundation",
+ "core-foundation 0.9.1",
+ "core-graphics 0.22.2",
  "foreign-types",
  "libc",
  "objc",
@@ -504,6 +508,19 @@ dependencies = [
  "libc",
 ]
 
+[[package]]
+name = "core-graphics"
+version = "0.22.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "269f35f69b542b80e736a20a89a05215c0ce80c2c03c514abb2e318b78379d86"
+dependencies = [
+ "bitflags",
+ "core-foundation 0.9.1",
+ "core-graphics-types",
+ "foreign-types",
+ "libc",
+]
+
 [[package]]
 name = "core-graphics-types"
 version = "0.1.1"
@@ -524,7 +541,7 @@ checksum = "34ecad23610ad9757664d644e369246edde1803fcb43ed72876565098a5d3828"
 dependencies = [
  "cfg-if 0.1.10",
  "core-foundation-sys 0.7.0",
- "core-graphics",
+ "core-graphics 0.19.2",
  "libc",
  "objc",
 ]
@@ -713,6 +730,16 @@ dependencies = [
  "memchr",
 ]
 
+[[package]]
+name = "ctor"
+version = "0.1.19"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e8f45d9ad417bcef4817d614a501ab55cdd96a6fdb24f49aab89a54acfd66b19"
+dependencies = [
+ "quote 1.0.9",
+ "syn 1.0.61",
+]
+
 [[package]]
 name = "d3d12"
 version = "0.3.2"
@@ -724,6 +751,41 @@ dependencies = [
  "winapi 0.3.9",
 ]
 
+[[package]]
+name = "darling"
+version = "0.10.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0d706e75d87e35569db781a9b5e2416cff1236a47ed380831f959382ccd5f858"
+dependencies = [
+ "darling_core",
+ "darling_macro",
+]
+
+[[package]]
+name = "darling_core"
+version = "0.10.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f0c960ae2da4de88a91b2d920c2a7233b400bc33cb28453a2987822d8392519b"
+dependencies = [
+ "fnv",
+ "ident_case",
+ "proc-macro2 1.0.24",
+ "quote 1.0.9",
+ "strsim",
+ "syn 1.0.61",
+]
+
+[[package]]
+name = "darling_macro"
+version = "0.10.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d9b5a2f4ac4969822c62224815d069952656cadc7084fdca9751e6d959189b72"
+dependencies = [
+ "darling_core",
+ "quote 1.0.9",
+ "syn 1.0.61",
+]
+
 [[package]]
 name = "derivative"
 version = "2.2.0"
@@ -815,7 +877,7 @@ dependencies = [
  "fs_extra",
  "handlebars",
  "maplit",
- "pretty_assertions",
+ "pretty_assertions 0.5.1",
  "pulldown-cmark",
  "roc_builtins",
  "roc_can",
@@ -856,9 +918,9 @@ dependencies = [
 
 [[package]]
 name = "env_logger"
-version = "0.7.1"
+version = "0.8.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "44533bbbb3bb3c1fa17d9f2e4e38bbbaf8396ba82193c4cb1b6445d711445d36"
+checksum = "17392a012ea30ef05a610aa97dfb49496e71c9f676b27879922ea5bdf60d9d3f"
 dependencies = [
  "atty",
  "humantime",
@@ -1084,9 +1146,9 @@ dependencies = [
 
 [[package]]
 name = "gfx-auxil"
-version = "0.7.0"
+version = "0.8.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "07cd956b592970f08545b9325b87580eb95a51843b6f39da27b8667fec1a1216"
+checksum = "e7b33ecf067f2117668d91c9b0f2e5f223ebd1ffec314caa2f3de27bb580186d"
 dependencies = [
  "fxhash",
  "gfx-hal",
@@ -1095,9 +1157,9 @@ dependencies = [
 
 [[package]]
 name = "gfx-backend-dx11"
-version = "0.6.17"
+version = "0.7.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "54b43f06089866bdffe59b5a6801022c86b74d2c1dd28940a9cf301d3d014fbc"
+checksum = "f851d03c2e8f117e3702bf41201a4fafa447d5cb1276d5375870ae7573d069dd"
 dependencies = [
  "arrayvec",
  "bitflags",
@@ -1105,7 +1167,7 @@ dependencies = [
  "gfx-hal",
  "libloading 0.6.7",
  "log",
- "parking_lot 0.11.1",
+ "parking_lot",
  "range-alloc",
  "raw-window-handle",
  "smallvec",
@@ -1117,9 +1179,9 @@ dependencies = [
 
 [[package]]
 name = "gfx-backend-dx12"
-version = "0.6.13"
+version = "0.7.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "375014deed24d76b03604736dd899f0925158a1a96db90cbefb9cce070f71af7"
+checksum = "36dc6ba2b7647e2c2b27b8f74ff5ccdd53c703776588eee5b1de515fdcbd6bc9"
 dependencies = [
  "arrayvec",
  "bit-set",
@@ -1128,6 +1190,7 @@ dependencies = [
  "gfx-auxil",
  "gfx-hal",
  "log",
+ "parking_lot",
  "range-alloc",
  "raw-window-handle",
  "smallvec",
@@ -1137,9 +1200,9 @@ dependencies = [
 
 [[package]]
 name = "gfx-backend-empty"
-version = "0.6.0"
+version = "0.7.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2085227c12b78f6657a900c829f2d0deb46a9be3eaf86844fde263cdc218f77c"
+checksum = "9f07ef26a65954cfdd7b4c587f485100d1bb3b0bd6a51b02d817d6c87cca7a91"
 dependencies = [
  "gfx-hal",
  "log",
@@ -1147,10 +1210,33 @@ dependencies = [
 ]
 
 [[package]]
-name = "gfx-backend-metal"
-version = "0.6.5"
+name = "gfx-backend-gl"
+version = "0.7.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "273d60d5207f96d99e0d11d0718995f67e56533a9df1444d83baf787f4c3cb32"
+checksum = "c6717c50ab601efe4a669bfb44db615e3888695ac8263222aeaa702642b9fbc2"
+dependencies = [
+ "arrayvec",
+ "bitflags",
+ "gfx-auxil",
+ "gfx-hal",
+ "glow",
+ "js-sys",
+ "khronos-egl",
+ "libloading 0.6.7",
+ "log",
+ "naga",
+ "parking_lot",
+ "raw-window-handle",
+ "spirv_cross",
+ "wasm-bindgen",
+ "web-sys",
+]
+
+[[package]]
+name = "gfx-backend-metal"
+version = "0.7.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8dc54b456ece69ef49f8893269ebf24ac70969ed34ba2719c3f3abcc8fbff14e"
 dependencies = [
  "arrayvec",
  "bitflags",
@@ -1160,23 +1246,22 @@ dependencies = [
  "foreign-types",
  "gfx-auxil",
  "gfx-hal",
- "lazy_static",
  "log",
  "metal",
+ "naga",
  "objc",
- "parking_lot 0.11.1",
+ "parking_lot",
  "range-alloc",
  "raw-window-handle",
- "smallvec",
  "spirv_cross",
  "storage-map",
 ]
 
 [[package]]
 name = "gfx-backend-vulkan"
-version = "0.6.5"
+version = "0.7.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3a3a63cf61067a09b7d1ac480af3cb2ae0c5ede5bed294607bbd814cb1666c45"
+checksum = "dabe88b1a5c91e0f969b441cc57e70364858066e4ba937deeb62065654ef9bd9"
 dependencies = [
  "arrayvec",
  "ash",
@@ -1184,48 +1269,25 @@ dependencies = [
  "core-graphics-types",
  "gfx-hal",
  "inplace_it",
- "lazy_static",
  "log",
+ "naga",
  "objc",
+ "parking_lot",
  "raw-window-handle",
  "smallvec",
  "winapi 0.3.9",
- "x11",
-]
-
-[[package]]
-name = "gfx-descriptor"
-version = "0.2.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "cd8c7afcd000f279d541a490e27117e61037537279b9342279abf4938fe60c6b"
-dependencies = [
- "arrayvec",
- "fxhash",
- "gfx-hal",
- "log",
 ]
 
 [[package]]
 name = "gfx-hal"
-version = "0.6.0"
+version = "0.7.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "18d0754f5b7a43915fd7466883b2d1bb0800d7cc4609178d0b27bf143b9e5123"
+checksum = "c1d9cc8d3b573dda62d0baca4f02e0209786e22c562caff001d77c389008781d"
 dependencies = [
  "bitflags",
+ "naga",
  "raw-window-handle",
-]
-
-[[package]]
-name = "gfx-memory"
-version = "0.2.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "dccdda5d2b39412f4ca2cb15c70b5a82783a86b0606f5e985342754c8ed88f05"
-dependencies = [
- "bit-set",
- "fxhash",
- "gfx-hal",
- "log",
- "slab",
+ "thiserror",
 ]
 
 [[package]]
@@ -1234,6 +1296,18 @@ version = "0.23.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "f6503fe142514ca4799d4c26297c4248239fe8838d827db6bd6065c6ed29a6ce"
 
+[[package]]
+name = "glow"
+version = "0.7.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "072136d2c3783f3a92f131acb227bc806d3886278e2a4dc1e9990ec89ef9e70b"
+dependencies = [
+ "js-sys",
+ "slotmap",
+ "wasm-bindgen",
+ "web-sys",
+]
+
 [[package]]
 name = "glyph_brush"
 version = "0.7.2"
@@ -1243,7 +1317,7 @@ dependencies = [
  "glyph_brush_draw_cache",
  "glyph_brush_layout",
  "log",
- "ordered-float 2.1.1",
+ "ordered-float",
  "rustc-hash",
  "twox-hash",
 ]
@@ -1273,6 +1347,47 @@ dependencies = [
  "xi-unicode",
 ]
 
+[[package]]
+name = "gpu-alloc"
+version = "0.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1e7724b9aef57ea36d70faf54e0ee6265f86e41de16bed8333efdeab5b00e16b"
+dependencies = [
+ "bitflags",
+ "gpu-alloc-types",
+ "tracing",
+]
+
+[[package]]
+name = "gpu-alloc-types"
+version = "0.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "54804d0d6bc9d7f26db4eaec1ad10def69b599315f487d32c334a80d1efe67a5"
+dependencies = [
+ "bitflags",
+]
+
+[[package]]
+name = "gpu-descriptor"
+version = "0.1.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e8a70f1e87a3840ed6a3e99e02c2b861e4dbdf26f0d07e38f42ea5aff46cfce2"
+dependencies = [
+ "bitflags",
+ "gpu-descriptor-types",
+ "hashbrown",
+ "tracing",
+]
+
+[[package]]
+name = "gpu-descriptor-types"
+version = "0.1.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "363e3677e55ad168fef68cf9de3a4a310b53124c5e784c53a1d70e92d23f2126"
+dependencies = [
+ "bitflags",
+]
+
 [[package]]
 name = "half"
 version = "1.7.1"
@@ -1288,7 +1403,7 @@ dependencies = [
  "log",
  "pest",
  "pest_derive",
- "quick-error 2.0.0",
+ "quick-error",
  "serde",
  "serde_json",
 ]
@@ -1298,6 +1413,9 @@ name = "hashbrown"
 version = "0.9.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "d7afe4a420e3fe79967a00898cc1f4db7c8a49a9333a29f8a4bd76a253d5cd04"
+dependencies = [
+ "ahash",
+]
 
 [[package]]
 name = "heck"
@@ -1319,12 +1437,15 @@ dependencies = [
 
 [[package]]
 name = "humantime"
-version = "1.3.0"
+version = "2.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "df004cfca50ef23c36850aaaa59ad52cc70d0e90243c3c7737a4dd32dc7a3c4f"
-dependencies = [
- "quick-error 1.2.3",
-]
+checksum = "9a3a5bfb195931eeb336b2a7b4d761daec841b97f947d34394601737a7bba5e4"
+
+[[package]]
+name = "ident_case"
+version = "1.0.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b9e0384b61958566e926dc50660321d12159025e767c18e043daf26b70104c39"
 
 [[package]]
 name = "im"
@@ -1335,7 +1456,21 @@ dependencies = [
  "bitmaps",
  "rand_core 0.5.1",
  "rand_xoshiro",
- "sized-chunks",
+ "sized-chunks 0.5.3",
+ "typenum",
+ "version_check",
+]
+
+[[package]]
+name = "im"
+version = "15.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "111c1983f3c5bb72732df25cddacee9b546d08325fb584b5ebd38148be7b0246"
+dependencies = [
+ "bitmaps",
+ "rand_core 0.5.1",
+ "rand_xoshiro",
+ "sized-chunks 0.6.4",
  "typenum",
  "version_check",
 ]
@@ -1349,7 +1484,21 @@ dependencies = [
  "bitmaps",
  "rand_core 0.5.1",
  "rand_xoshiro",
- "sized-chunks",
+ "sized-chunks 0.5.3",
+ "typenum",
+ "version_check",
+]
+
+[[package]]
+name = "im-rc"
+version = "15.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3ca8957e71f04a205cb162508f9326aea04676c8dfd0711220190d6b83664f3f"
+dependencies = [
+ "bitmaps",
+ "rand_core 0.5.1",
+ "rand_xoshiro",
+ "sized-chunks 0.6.4",
  "typenum",
  "version_check",
 ]
@@ -1374,6 +1523,15 @@ dependencies = [
  "proc-macro-hack",
 ]
 
+[[package]]
+name = "indoc"
+version = "1.0.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e5a75aeaaef0ce18b58056d306c27b07436fbb34b8816c53094b76dd81803136"
+dependencies = [
+ "unindent",
+]
+
 [[package]]
 name = "indoc-impl"
 version = "0.3.6"
@@ -1397,7 +1555,7 @@ dependencies = [
  "libc",
  "llvm-sys",
  "once_cell",
- "parking_lot 0.11.1",
+ "parking_lot",
  "regex",
 ]
 
@@ -1482,9 +1640,9 @@ dependencies = [
 
 [[package]]
 name = "js-sys"
-version = "0.3.48"
+version = "0.3.46"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "dc9f84f9b115ce7843d60706df1422a916680bfdfcbdb0447c5614ff9d7e4d78"
+checksum = "cf3d7383929f7c9c7c2d0fa596f325832df98c3704f2c60553080f7127a58175"
 dependencies = [
  "wasm-bindgen",
 ]
@@ -1499,6 +1657,16 @@ dependencies = [
  "winapi-build",
 ]
 
+[[package]]
+name = "khronos-egl"
+version = "3.0.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b19cc4a81304db2a0ad69740e83cdc3a9364e3f9bd6d88a87288a4c2deec927b"
+dependencies = [
+ "libc",
+ "libloading 0.6.7",
+]
+
 [[package]]
 name = "lazy-bytes-cast"
 version = "5.0.1"
@@ -1543,15 +1711,6 @@ dependencies = [
  "winapi 0.3.9",
 ]
 
-[[package]]
-name = "line_drawing"
-version = "0.7.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5cc7ad3d82c845bdb5dde34ffdcc7a5fb4d2996e1e1ee0f19c33bc80e15196b9"
-dependencies = [
- "num-traits",
-]
-
 [[package]]
 name = "linked-hash-map"
 version = "0.5.4"
@@ -1571,15 +1730,6 @@ dependencies = [
  "semver",
 ]
 
-[[package]]
-name = "lock_api"
-version = "0.3.4"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c4da24a77a3d8a6d4862d95f72e6fdb9c09a643ecdb402d754004a557f2bec75"
-dependencies = [
- "scopeguard",
-]
-
 [[package]]
 name = "lock_api"
 version = "0.4.2"
@@ -1625,16 +1775,6 @@ version = "2.3.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "0ee1c47aaa256ecabcaea351eae4a9b01ef39ed810004e298d2511ed284b1525"
 
-[[package]]
-name = "memmap"
-version = "0.7.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6585fd95e7bb50d6cc31e20d4cf9afb4e2ba16c5846fc76793f11218da9c475b"
-dependencies = [
- "libc",
- "winapi 0.3.9",
-]
-
 [[package]]
 name = "memmap2"
 version = "0.1.0"
@@ -1664,9 +1804,9 @@ dependencies = [
 
 [[package]]
 name = "metal"
-version = "0.20.0"
+version = "0.21.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5c4e8a431536529327e28c9ba6992f2cb0c15d4222f0602a16e6d7695ff3bccf"
+checksum = "4598d719460ade24c7d91f335daf055bf2a7eec030728ce751814c50cdd6a26c"
 dependencies = [
  "bitflags",
  "block",
@@ -1731,48 +1871,64 @@ dependencies = [
 
 [[package]]
 name = "naga"
-version = "0.2.0"
+version = "0.3.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0873deb76cf44b7454fba7b2ba6a89d3de70c08aceffd2c489379b3d9d08e661"
+checksum = "05089b2acdf0e6a962cdbf5e328402345a27f59fcde1a59fe97a73e8149d416f"
 dependencies = [
+ "bit-set",
  "bitflags",
  "fxhash",
  "log",
  "num-traits",
+ "petgraph",
  "spirv_headers",
  "thiserror",
 ]
 
 [[package]]
 name = "ndk"
-version = "0.1.0"
+version = "0.2.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "95a356cafe20aee088789830bfea3a61336e84ded9e545e00d3869ce95dcb80c"
+checksum = "5eb167c1febed0a496639034d0c76b3b74263636045db5489eee52143c246e73"
 dependencies = [
  "jni-sys",
  "ndk-sys",
  "num_enum",
+ "thiserror",
 ]
 
 [[package]]
 name = "ndk-glue"
-version = "0.1.0"
+version = "0.2.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d1730ee2e3de41c3321160a6da815f008c4006d71b095880ea50e17cf52332b8"
+checksum = "bdf399b8b7a39c6fb153c4ec32c72fd5fe789df24a647f229c239aa7adb15241"
 dependencies = [
- "android_log-sys",
  "lazy_static",
  "libc",
  "log",
  "ndk",
+ "ndk-macro",
  "ndk-sys",
 ]
 
 [[package]]
-name = "ndk-sys"
-version = "0.1.0"
+name = "ndk-macro"
+version = "0.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2b2820aca934aba5ed91c79acc72b6a44048ceacc5d36c035ed4e051f12d887d"
+checksum = "05d1c6307dc424d0f65b9b06e94f88248e6305726b14729fd67a5e47b2dc481d"
+dependencies = [
+ "darling",
+ "proc-macro-crate",
+ "proc-macro2 1.0.24",
+ "quote 1.0.9",
+ "syn 1.0.61",
+]
+
+[[package]]
+name = "ndk-sys"
+version = "0.2.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c44922cb3dbb1c70b5e5f443d63b64363a898564d739ba5198e3a9138442868d"
 
 [[package]]
 name = "net2"
@@ -1785,19 +1941,6 @@ dependencies = [
  "winapi 0.3.9",
 ]
 
-[[package]]
-name = "nix"
-version = "0.14.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6c722bee1037d430d0f8e687bbdbf222f27cc6e4e68d5caf630857bb2b6dbdce"
-dependencies = [
- "bitflags",
- "cc",
- "cfg-if 0.1.10",
- "libc",
- "void",
-]
-
 [[package]]
 name = "nix"
 version = "0.18.0"
@@ -1960,15 +2103,6 @@ version = "0.2.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "2839e79665f131bdb5782e51f2c6c9599c133c6098982a54c794358bf432529c"
 
-[[package]]
-name = "ordered-float"
-version = "1.1.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3305af35278dd29f46fcdd139e0b1fbfae2153f0e5928b39b035542dd31e37b7"
-dependencies = [
- "num-traits",
-]
-
 [[package]]
 name = "ordered-float"
 version = "2.1.1"
@@ -1978,13 +2112,31 @@ dependencies = [
  "num-traits",
 ]
 
+[[package]]
+name = "output_vt100"
+version = "0.1.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "53cdc5b785b7a58c5aad8216b3dfa114df64b0b06ae6e1501cef91df2fbdf8f9"
+dependencies = [
+ "winapi 0.3.9",
+]
+
+[[package]]
+name = "owned_ttf_parser"
+version = "0.6.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9f923fb806c46266c02ab4a5b239735c144bdeda724a50ed058e5226f594cde3"
+dependencies = [
+ "ttf-parser 0.6.2",
+]
+
 [[package]]
 name = "owned_ttf_parser"
 version = "0.12.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "3a3c7a20e3f122223e68eef6ca58e39bc1ea8a1d83418ba4c2c1ba189d2ee355"
 dependencies = [
- "ttf-parser",
+ "ttf-parser 0.12.0",
 ]
 
 [[package]]
@@ -2021,16 +2173,6 @@ dependencies = [
  "syn 1.0.61",
 ]
 
-[[package]]
-name = "parking_lot"
-version = "0.10.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d3a704eb390aafdc107b0e392f56a82b668e3a71366993b5340f5833fd62505e"
-dependencies = [
- "lock_api 0.3.4",
- "parking_lot_core 0.7.2",
-]
-
 [[package]]
 name = "parking_lot"
 version = "0.11.1"
@@ -2038,22 +2180,8 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "6d7744ac029df22dca6284efe4e898991d28e3085c706c972bcd7da4a27a15eb"
 dependencies = [
  "instant",
- "lock_api 0.4.2",
- "parking_lot_core 0.8.3",
-]
-
-[[package]]
-name = "parking_lot_core"
-version = "0.7.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d58c7c768d4ba344e3e8d72518ac13e259d7c7ade24167003b8488e10b6740a3"
-dependencies = [
- "cfg-if 0.1.10",
- "cloudabi",
- "libc",
- "redox_syscall 0.1.57",
- "smallvec",
- "winapi 0.3.9",
+ "lock_api",
+ "parking_lot_core",
 ]
 
 [[package]]
@@ -2238,6 +2366,18 @@ dependencies = [
  "difference",
 ]
 
+[[package]]
+name = "pretty_assertions"
+version = "0.6.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3f81e1644e1b54f5a68959a29aa86cde704219254669da328ecfdf6a1f09d427"
+dependencies = [
+ "ansi_term",
+ "ctor",
+ "difference",
+ "output_vt100",
+]
+
 [[package]]
 name = "proc-macro-crate"
 version = "0.1.5"
@@ -2314,12 +2454,6 @@ dependencies = [
  "unicase",
 ]
 
-[[package]]
-name = "quick-error"
-version = "1.2.3"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a1d01941d82fa2ab50be1e79e6714289dd7cde78eba4c074bc5a4374f650dfe0"
-
 [[package]]
 name = "quick-error"
 version = "2.0.0"
@@ -2338,6 +2472,17 @@ dependencies = [
  "rand_core 0.4.2",
 ]
 
+[[package]]
+name = "quickcheck"
+version = "1.0.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "588f6378e4dd99458b60ec275b4477add41ce4fa9f64dcba6f15adccb19b50d6"
+dependencies = [
+ "env_logger 0.8.3",
+ "log",
+ "rand 0.8.3",
+]
+
 [[package]]
 name = "quickcheck_macros"
 version = "0.8.0"
@@ -2349,6 +2494,17 @@ dependencies = [
  "syn 0.15.44",
 ]
 
+[[package]]
+name = "quickcheck_macros"
+version = "1.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b22a693222d716a9587786f37ac3f6b4faedb5b80c23914e7303ff5a1d8016e9"
+dependencies = [
+ "proc-macro2 1.0.24",
+ "quote 1.0.9",
+ "syn 1.0.61",
+]
+
 [[package]]
 name = "quote"
 version = "0.6.13"
@@ -2688,16 +2844,16 @@ name = "roc_build"
 version = "0.1.0"
 dependencies = [
  "bumpalo",
- "im",
- "im-rc",
- "indoc",
+ "im 14.3.0",
+ "im-rc 14.3.0",
+ "indoc 0.3.6",
  "inkwell",
  "inlinable_string",
  "libloading 0.6.7",
  "maplit",
- "pretty_assertions",
- "quickcheck",
- "quickcheck_macros",
+ "pretty_assertions 0.5.1",
+ "quickcheck 0.8.5",
+ "quickcheck_macros 0.8.0",
  "roc_builtins",
  "roc_can",
  "roc_collections",
@@ -2721,11 +2877,11 @@ dependencies = [
 name = "roc_builtins"
 version = "0.1.0"
 dependencies = [
- "indoc",
+ "indoc 0.3.6",
  "maplit",
- "pretty_assertions",
- "quickcheck",
- "quickcheck_macros",
+ "pretty_assertions 0.5.1",
+ "quickcheck 0.8.5",
+ "quickcheck_macros 0.8.0",
  "roc_collections",
  "roc_module",
  "roc_region",
@@ -2737,14 +2893,14 @@ name = "roc_can"
 version = "0.1.0"
 dependencies = [
  "bumpalo",
- "im",
- "im-rc",
- "indoc",
+ "im 14.3.0",
+ "im-rc 14.3.0",
+ "indoc 0.3.6",
  "inlinable_string",
  "maplit",
- "pretty_assertions",
- "quickcheck",
- "quickcheck_macros",
+ "pretty_assertions 0.5.1",
+ "quickcheck 0.8.5",
+ "quickcheck_macros 0.8.0",
  "roc_collections",
  "roc_module",
  "roc_parse",
@@ -2761,17 +2917,17 @@ dependencies = [
  "bumpalo",
  "clap 3.0.0-beta.1",
  "const_format",
- "im",
- "im-rc",
- "indoc",
+ "im 14.3.0",
+ "im-rc 14.3.0",
+ "indoc 0.3.6",
  "inkwell",
  "inlinable_string",
  "libc",
  "libloading 0.6.7",
  "maplit",
- "pretty_assertions",
- "quickcheck",
- "quickcheck_macros",
+ "pretty_assertions 0.5.1",
+ "quickcheck 0.8.5",
+ "quickcheck_macros 0.8.0",
  "roc_build",
  "roc_builtins",
  "roc_can",
@@ -2805,8 +2961,8 @@ name = "roc_collections"
 version = "0.1.0"
 dependencies = [
  "bumpalo",
- "im",
- "im-rc",
+ "im 14.3.0",
+ "im-rc 14.3.0",
  "wyhash",
 ]
 
@@ -2814,11 +2970,11 @@ dependencies = [
 name = "roc_constrain"
 version = "0.1.0"
 dependencies = [
- "indoc",
+ "indoc 0.3.6",
  "maplit",
- "pretty_assertions",
- "quickcheck",
- "quickcheck_macros",
+ "pretty_assertions 0.5.1",
+ "quickcheck 0.8.5",
+ "quickcheck_macros 0.8.0",
  "roc_builtins",
  "roc_can",
  "roc_collections",
@@ -2839,12 +2995,12 @@ dependencies = [
  "colored",
  "copypasta",
  "criterion",
- "env_logger 0.7.1",
+ "env_logger 0.8.3",
  "futures",
  "glyph_brush",
- "im",
- "im-rc",
- "indoc",
+ "im 15.0.0",
+ "im-rc 15.0.0",
+ "indoc 1.0.3",
  "inlinable_string",
  "libc",
  "log",
@@ -2853,9 +3009,9 @@ dependencies = [
  "palette",
  "pest",
  "pest_derive",
- "pretty_assertions",
- "quickcheck",
- "quickcheck_macros",
+ "pretty_assertions 0.6.1",
+ "quickcheck 1.0.3",
+ "quickcheck_macros 1.0.0",
  "rand 0.8.3",
  "roc_can",
  "roc_collections",
@@ -2879,14 +3035,14 @@ name = "roc_fmt"
 version = "0.1.0"
 dependencies = [
  "bumpalo",
- "im",
- "im-rc",
- "indoc",
+ "im 14.3.0",
+ "im-rc 14.3.0",
+ "indoc 0.3.6",
  "inlinable_string",
  "maplit",
- "pretty_assertions",
- "quickcheck",
- "quickcheck_macros",
+ "pretty_assertions 0.5.1",
+ "quickcheck 0.8.5",
+ "quickcheck_macros 0.8.0",
  "roc_collections",
  "roc_module",
  "roc_parse",
@@ -2899,16 +3055,16 @@ version = "0.1.0"
 dependencies = [
  "bumpalo",
  "either",
- "im",
- "im-rc",
- "indoc",
+ "im 14.3.0",
+ "im-rc 14.3.0",
+ "indoc 0.3.6",
  "inkwell",
  "inlinable_string",
  "libc",
  "maplit",
- "pretty_assertions",
- "quickcheck",
- "quickcheck_macros",
+ "pretty_assertions 0.5.1",
+ "quickcheck 0.8.5",
+ "quickcheck_macros 0.8.0",
  "roc_build",
  "roc_builtins",
  "roc_can",
@@ -2933,18 +3089,18 @@ name = "roc_gen_dev"
 version = "0.1.0"
 dependencies = [
  "bumpalo",
- "im",
- "im-rc",
- "indoc",
+ "im 14.3.0",
+ "im-rc 14.3.0",
+ "indoc 0.3.6",
  "inlinable_string",
  "itertools 0.9.0",
  "libc",
  "libloading 0.6.7",
  "maplit",
  "object 0.22.0",
- "pretty_assertions",
- "quickcheck",
- "quickcheck_macros",
+ "pretty_assertions 0.5.1",
+ "quickcheck 0.8.5",
+ "quickcheck_macros 0.8.0",
  "roc_build",
  "roc_builtins",
  "roc_can",
@@ -2972,14 +3128,14 @@ version = "0.1.0"
 dependencies = [
  "bumpalo",
  "crossbeam",
- "indoc",
+ "indoc 0.3.6",
  "inlinable_string",
  "maplit",
  "num_cpus",
- "parking_lot 0.11.1",
- "pretty_assertions",
- "quickcheck",
- "quickcheck_macros",
+ "parking_lot",
+ "pretty_assertions 0.5.1",
+ "quickcheck 0.8.5",
+ "quickcheck_macros 0.8.0",
  "roc_builtins",
  "roc_can",
  "roc_collections",
@@ -3002,11 +3158,11 @@ name = "roc_module"
 version = "0.1.0"
 dependencies = [
  "bumpalo",
- "indoc",
+ "indoc 0.3.6",
  "inlinable_string",
  "lazy_static",
  "maplit",
- "pretty_assertions",
+ "pretty_assertions 0.5.1",
  "roc_collections",
  "roc_region",
 ]
@@ -3016,12 +3172,12 @@ name = "roc_mono"
 version = "0.1.0"
 dependencies = [
  "bumpalo",
- "indoc",
+ "indoc 0.3.6",
  "linked-hash-map",
  "maplit",
- "pretty_assertions",
- "quickcheck",
- "quickcheck_macros",
+ "pretty_assertions 0.5.1",
+ "quickcheck 0.8.5",
+ "quickcheck_macros 0.8.0",
  "roc_builtins",
  "roc_can",
  "roc_collections",
@@ -3043,11 +3199,11 @@ version = "0.1.0"
 dependencies = [
  "bumpalo",
  "encode_unicode",
- "indoc",
+ "indoc 0.3.6",
  "inlinable_string",
- "pretty_assertions",
- "quickcheck",
- "quickcheck_macros",
+ "pretty_assertions 0.5.1",
+ "quickcheck 0.8.5",
+ "quickcheck_macros 0.8.0",
  "roc_collections",
  "roc_module",
  "roc_region",
@@ -3057,12 +3213,12 @@ dependencies = [
 name = "roc_problem"
 version = "0.1.0"
 dependencies = [
- "indoc",
+ "indoc 0.3.6",
  "inlinable_string",
  "maplit",
- "pretty_assertions",
- "quickcheck",
- "quickcheck_macros",
+ "pretty_assertions 0.5.1",
+ "quickcheck 0.8.5",
+ "quickcheck_macros 0.8.0",
  "roc_collections",
  "roc_module",
  "roc_parse",
@@ -3079,14 +3235,14 @@ version = "0.1.0"
 dependencies = [
  "bumpalo",
  "distance",
- "im",
- "im-rc",
- "indoc",
+ "im 14.3.0",
+ "im-rc 14.3.0",
+ "indoc 0.3.6",
  "inlinable_string",
  "maplit",
- "pretty_assertions",
- "quickcheck",
- "quickcheck_macros",
+ "pretty_assertions 0.5.1",
+ "quickcheck 0.8.5",
+ "quickcheck_macros 0.8.0",
  "roc_builtins",
  "roc_can",
  "roc_collections",
@@ -3106,11 +3262,11 @@ name = "roc_solve"
 version = "0.1.0"
 dependencies = [
  "bumpalo",
- "indoc",
+ "indoc 0.3.6",
  "maplit",
- "pretty_assertions",
- "quickcheck",
- "quickcheck_macros",
+ "pretty_assertions 0.5.1",
+ "quickcheck 0.8.5",
+ "quickcheck_macros 0.8.0",
  "roc_builtins",
  "roc_can",
  "roc_collections",
@@ -3136,12 +3292,12 @@ dependencies = [
 name = "roc_types"
 version = "0.1.0"
 dependencies = [
- "indoc",
+ "indoc 0.3.6",
  "inlinable_string",
  "maplit",
- "pretty_assertions",
- "quickcheck",
- "quickcheck_macros",
+ "pretty_assertions 0.5.1",
+ "quickcheck 0.8.5",
+ "quickcheck_macros 0.8.0",
  "roc_collections",
  "roc_module",
  "roc_region",
@@ -3152,11 +3308,11 @@ dependencies = [
 name = "roc_unify"
 version = "0.1.0"
 dependencies = [
- "indoc",
+ "indoc 0.3.6",
  "maplit",
- "pretty_assertions",
- "quickcheck",
- "quickcheck_macros",
+ "pretty_assertions 0.5.1",
+ "quickcheck 0.8.5",
+ "quickcheck_macros 0.8.0",
  "roc_collections",
  "roc_module",
  "roc_types",
@@ -3194,22 +3350,12 @@ dependencies = [
 
 [[package]]
 name = "rusttype"
-version = "0.7.9"
+version = "0.9.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "310942406a39981bed7e12b09182a221a29e0990f3e7e0c971f131922ed135d5"
+checksum = "dc7c727aded0be18c5b80c1640eae0ac8e396abf6fa8477d96cb37d18ee5ec59"
 dependencies = [
- "rusttype 0.8.3",
-]
-
-[[package]]
-name = "rusttype"
-version = "0.8.3"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9f61411055101f7b60ecf1041d87fb74205fb20b0c7a723f07ef39174cf6b4c0"
-dependencies = [
- "approx 0.3.2",
- "ordered-float 1.1.1",
- "stb_truetype",
+ "ab_glyph_rasterizer",
+ "owned_ttf_parser 0.6.0",
 ]
 
 [[package]]
@@ -3345,7 +3491,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "e0bccbcf40c8938196944a3da0e133e031a33f4d6b72db3bda3cc556e361905d"
 dependencies = [
  "lazy_static",
- "parking_lot 0.11.1",
+ "parking_lot",
  "serial_test_derive",
 ]
 
@@ -3388,49 +3534,51 @@ dependencies = [
  "typenum",
 ]
 
+[[package]]
+name = "sized-chunks"
+version = "0.6.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "65e65d6a9f13cd78f361ea5a2cf53a45d67cdda421ba0316b9be101560f3d207"
+dependencies = [
+ "bitmaps",
+ "typenum",
+]
+
 [[package]]
 name = "slab"
 version = "0.4.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "c111b5bd5695e56cffe5129854aa230b39c93a305372fdbb2668ca2394eea9f8"
 
+[[package]]
+name = "slotmap"
+version = "0.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c46a3482db8f247956e464d783693ece164ca056e6e67563ee5505bdb86452cd"
+
 [[package]]
 name = "smallvec"
 version = "1.6.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "fe0f37c9e8f3c5a4a66ad655a93c74daac4ad00c441533bf5c6e7990bb42604e"
 
-[[package]]
-name = "smithay-client-toolkit"
-version = "0.6.6"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "421c8dc7acf5cb205b88160f8b4cc2c5cfabe210e43b2f80f009f4c1ef910f1d"
-dependencies = [
- "andrew",
- "bitflags",
- "dlib 0.4.2",
- "lazy_static",
- "memmap",
- "nix 0.14.1",
- "wayland-client 0.23.6",
- "wayland-protocols 0.23.6",
-]
-
 [[package]]
 name = "smithay-client-toolkit"
 version = "0.12.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "4750c76fd5d3ac95fa3ed80fe667d6a3d8590a960e5b575b98eea93339a80b80"
 dependencies = [
+ "andrew",
  "bitflags",
+ "calloop",
  "dlib 0.4.2",
  "lazy_static",
  "log",
  "memmap2",
  "nix 0.18.0",
- "wayland-client 0.28.5",
+ "wayland-client",
  "wayland-cursor",
- "wayland-protocols 0.28.5",
+ "wayland-protocols",
 ]
 
 [[package]]
@@ -3439,8 +3587,8 @@ version = "0.6.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "06384dfaf645908220d976ae24ed39f6cf92efecb0225ea0a948e403014de527"
 dependencies = [
- "smithay-client-toolkit 0.12.3",
- "wayland-client 0.28.5",
+ "smithay-client-toolkit",
+ "wayland-client",
 ]
 
 [[package]]
@@ -3467,9 +3615,9 @@ dependencies = [
 
 [[package]]
 name = "spirv_cross"
-version = "0.22.2"
+version = "0.23.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0ebd49af36be83ecd6290b57147e2a0e26145b832634b17146d934b197ca3713"
+checksum = "60647fadbf83c4a72f0d7ea67a7ca3a81835cf442b8deae5c134c3e0055b2e14"
 dependencies = [
  "cc",
  "js-sys",
@@ -3492,22 +3640,13 @@ version = "1.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "a2eb9349b6444b326872e140eb1cf5e7c522154d69e7a0ffb0fb81c06b37543f"
 
-[[package]]
-name = "stb_truetype"
-version = "0.3.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f77b6b07e862c66a9f3e62a07588fee67cd90a9135a2b942409f195507b4fb51"
-dependencies = [
- "byteorder",
-]
-
 [[package]]
 name = "storage-map"
 version = "0.3.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "418bb14643aa55a7841d5303f72cf512cfb323b8cc221d51580500a1ca75206c"
 dependencies = [
- "lock_api 0.4.2",
+ "lock_api",
 ]
 
 [[package]]
@@ -3605,16 +3744,16 @@ version = "0.1.0"
 dependencies = [
  "bumpalo",
  "either",
- "im",
- "im-rc",
- "indoc",
+ "im 14.3.0",
+ "im-rc 14.3.0",
+ "indoc 0.3.6",
  "inkwell",
  "inlinable_string",
  "libc",
  "libloading 0.6.7",
  "maplit",
- "quickcheck",
- "quickcheck_macros",
+ "quickcheck 0.8.5",
+ "quickcheck_macros 0.8.0",
  "roc_build",
  "roc_builtins",
  "roc_can",
@@ -3732,9 +3871,21 @@ checksum = "01ebdc2bb4498ab1ab5f5b73c5803825e60199229ccba0698170e3be0e7f959f"
 dependencies = [
  "cfg-if 1.0.0",
  "pin-project-lite 0.2.6",
+ "tracing-attributes",
  "tracing-core",
 ]
 
+[[package]]
+name = "tracing-attributes"
+version = "0.1.13"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a8a9bd1db7706f2373a190b0d067146caa39350c486f3d455b0e33b431f94c07"
+dependencies = [
+ "proc-macro2 1.0.24",
+ "quote 1.0.9",
+ "syn 1.0.61",
+]
+
 [[package]]
 name = "tracing-core"
 version = "0.1.17"
@@ -3744,6 +3895,12 @@ dependencies = [
  "lazy_static",
 ]
 
+[[package]]
+name = "ttf-parser"
+version = "0.6.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3e5d7cd7ab3e47dda6e56542f4bbf3824c15234958c6e1bd6aaa347e93499fdc"
+
 [[package]]
 name = "ttf-parser"
 version = "0.12.0"
@@ -3868,12 +4025,6 @@ version = "0.9.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "b5a972e5669d67ba988ce3dc826706fb0a8b01471c088cb0b6110b805cc36aed"
 
-[[package]]
-name = "void"
-version = "1.0.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6a02e4885ed3bc0f2de90ea6dd45ebcbb66dacffe03547fadbb0eeae2770887d"
-
 [[package]]
 name = "vte"
 version = "0.3.3"
@@ -3908,9 +4059,9 @@ checksum = "fd6fbd9a79829dd1ad0cc20627bf1ed606756a7f77edff7b66b7064f9cb327c6"
 
 [[package]]
 name = "wasm-bindgen"
-version = "0.2.71"
+version = "0.2.69"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7ee1280240b7c461d6a0071313e08f34a60b0365f14260362e5a2b17d1d31aa7"
+checksum = "3cd364751395ca0f68cafb17666eee36b63077fb5ecd972bbcd74c90c4bf736e"
 dependencies = [
  "cfg-if 1.0.0",
  "wasm-bindgen-macro",
@@ -3918,9 +4069,9 @@ dependencies = [
 
 [[package]]
 name = "wasm-bindgen-backend"
-version = "0.2.71"
+version = "0.2.69"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5b7d8b6942b8bb3a9b0e73fc79b98095a27de6fa247615e59d096754a3bc2aa8"
+checksum = "1114f89ab1f4106e5b55e688b828c0ab0ea593a1ea7c094b141b14cbaaec2d62"
 dependencies = [
  "bumpalo",
  "lazy_static",
@@ -3933,9 +4084,9 @@ dependencies = [
 
 [[package]]
 name = "wasm-bindgen-futures"
-version = "0.4.21"
+version = "0.4.19"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8e67a5806118af01f0d9045915676b22aaebecf4178ae7021bc171dab0b897ab"
+checksum = "1fe9756085a84584ee9457a002b7cdfe0bfff169f45d2591d8be1345a6780e35"
 dependencies = [
  "cfg-if 1.0.0",
  "js-sys",
@@ -3945,9 +4096,9 @@ dependencies = [
 
 [[package]]
 name = "wasm-bindgen-macro"
-version = "0.2.71"
+version = "0.2.69"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e5ac38da8ef716661f0f36c0d8320b89028efe10c7c0afde65baffb496ce0d3b"
+checksum = "7a6ac8995ead1f084a8dea1e65f194d0973800c7f571f6edd70adf06ecf77084"
 dependencies = [
  "quote 1.0.9",
  "wasm-bindgen-macro-support",
@@ -3955,9 +4106,9 @@ dependencies = [
 
 [[package]]
 name = "wasm-bindgen-macro-support"
-version = "0.2.71"
+version = "0.2.69"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "cc053ec74d454df287b9374ee8abb36ffd5acb95ba87da3ba5b7d3fe20eb401e"
+checksum = "b5a48c72f299d80557c7c62e37e7225369ecc0c963964059509fbafe917c7549"
 dependencies = [
  "proc-macro2 1.0.24",
  "quote 1.0.9",
@@ -3968,9 +4119,9 @@ dependencies = [
 
 [[package]]
 name = "wasm-bindgen-shared"
-version = "0.2.71"
+version = "0.2.69"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7d6f8ec44822dd71f5f221a5847fb34acd9060535c1211b70a05844c0f6383b1"
+checksum = "7e7811dd7f9398f14cc76efd356f98f03aa30419dea46aa810d71e819fc97158"
 
 [[package]]
 name = "wasmparser"
@@ -3978,23 +4129,6 @@ version = "0.57.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "32fddd575d477c6e9702484139cf9f23dcd554b06d185ed0f56c857dd3a47aa6"
 
-[[package]]
-name = "wayland-client"
-version = "0.23.6"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "af1080ebe0efabcf12aef2132152f616038f2d7dcbbccf7b2d8c5270fe14bcda"
-dependencies = [
- "bitflags",
- "calloop",
- "downcast-rs",
- "libc",
- "mio",
- "nix 0.14.1",
- "wayland-commons 0.23.6",
- "wayland-scanner 0.23.6",
- "wayland-sys 0.23.6",
-]
-
 [[package]]
 name = "wayland-client"
 version = "0.28.5"
@@ -4006,19 +4140,9 @@ dependencies = [
  "libc",
  "nix 0.20.0",
  "scoped-tls",
- "wayland-commons 0.28.5",
- "wayland-scanner 0.28.5",
- "wayland-sys 0.28.5",
-]
-
-[[package]]
-name = "wayland-commons"
-version = "0.23.6"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "bb66b0d1a27c39bbce712b6372131c6e25149f03ffb0cd017cf8f7de8d66dbdb"
-dependencies = [
- "nix 0.14.1",
- "wayland-sys 0.23.6",
+ "wayland-commons",
+ "wayland-scanner",
+ "wayland-sys",
 ]
 
 [[package]]
@@ -4030,7 +4154,7 @@ dependencies = [
  "nix 0.20.0",
  "once_cell",
  "smallvec",
- "wayland-sys 0.28.5",
+ "wayland-sys",
 ]
 
 [[package]]
@@ -4040,22 +4164,10 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "b37e5455ec72f5de555ec39b5c3704036ac07c2ecd50d0bffe02d5fe2d4e65ab"
 dependencies = [
  "nix 0.20.0",
- "wayland-client 0.28.5",
+ "wayland-client",
  "xcursor",
 ]
 
-[[package]]
-name = "wayland-protocols"
-version = "0.23.6"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6cc286643656742777d55dc8e70d144fa4699e426ca8e9d4ef454f4bf15ffcf9"
-dependencies = [
- "bitflags",
- "wayland-client 0.23.6",
- "wayland-commons 0.23.6",
- "wayland-scanner 0.23.6",
-]
-
 [[package]]
 name = "wayland-protocols"
 version = "0.28.5"
@@ -4063,20 +4175,9 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "95df3317872bcf9eec096c864b69aa4769a1d5d6291a5b513f8ba0af0efbd52c"
 dependencies = [
  "bitflags",
- "wayland-client 0.28.5",
- "wayland-commons 0.28.5",
- "wayland-scanner 0.28.5",
-]
-
-[[package]]
-name = "wayland-scanner"
-version = "0.23.6"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "93b02247366f395b9258054f964fe293ddd019c3237afba9be2ccbe9e1651c3d"
-dependencies = [
- "proc-macro2 0.4.30",
- "quote 0.6.13",
- "xml-rs",
+ "wayland-client",
+ "wayland-commons",
+ "wayland-scanner",
 ]
 
 [[package]]
@@ -4090,16 +4191,6 @@ dependencies = [
  "xml-rs",
 ]
 
-[[package]]
-name = "wayland-sys"
-version = "0.23.6"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d94e89a86e6d6d7c7c9b19ebf48a03afaac4af6bc22ae570e9a24124b75358f4"
-dependencies = [
- "dlib 0.4.2",
- "lazy_static",
-]
-
 [[package]]
 name = "wayland-sys"
 version = "0.28.5"
@@ -4113,9 +4204,9 @@ dependencies = [
 
 [[package]]
 name = "web-sys"
-version = "0.3.48"
+version = "0.3.46"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ec600b26223b2948cedfde2a0aa6756dcf1fef616f43d7b3097aaf53a6c4d92b"
+checksum = "222b1ef9334f92a21d3fb53dc3fd80f30836959a90f9274a626d7e06315ba3c3"
 dependencies = [
  "js-sys",
  "wasm-bindgen",
@@ -4123,20 +4214,17 @@ dependencies = [
 
 [[package]]
 name = "wgpu"
-version = "0.6.2"
+version = "0.7.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "991903e4c9f5b7319732b30a3d0339e27a51ea992cea22769b5f6c7f7076af6d"
+checksum = "c60007fc3748278a36b458d96f86105f43aa5f0e412b15a5f934950d61ec26a9"
 dependencies = [
  "arrayvec",
- "futures",
- "gfx-backend-vulkan",
  "js-sys",
- "objc",
- "parking_lot 0.11.1",
+ "naga",
+ "parking_lot",
  "raw-window-handle",
  "smallvec",
  "tracing",
- "typed-arena",
  "wasm-bindgen",
  "wasm-bindgen-futures",
  "web-sys",
@@ -4146,24 +4234,26 @@ dependencies = [
 
 [[package]]
 name = "wgpu-core"
-version = "0.6.5"
+version = "0.7.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ea487deeae90e06d77eb8e6cef945247774e7c0a0a226d238b31e90633594365"
+checksum = "c89fa2cc5d72236461ac09c5be967012663e29cb62f1a972654cbf35e49dffa8"
 dependencies = [
  "arrayvec",
  "bitflags",
+ "cfg_aliases",
  "copyless",
  "fxhash",
  "gfx-backend-dx11",
  "gfx-backend-dx12",
  "gfx-backend-empty",
+ "gfx-backend-gl",
  "gfx-backend-metal",
  "gfx-backend-vulkan",
- "gfx-descriptor",
  "gfx-hal",
- "gfx-memory",
+ "gpu-alloc",
+ "gpu-descriptor",
  "naga",
- "parking_lot 0.11.1",
+ "parking_lot",
  "raw-window-handle",
  "smallvec",
  "thiserror",
@@ -4173,23 +4263,23 @@ dependencies = [
 
 [[package]]
 name = "wgpu-types"
-version = "0.6.1"
+version = "0.7.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1e3529528e608b54838ee618c3923b0f46e6db0334cfc6c42a16cf4ceb3bdb57"
+checksum = "72fa9ba80626278fd87351555c363378d08122d7601e58319be3d6fa85a87747"
 dependencies = [
  "bitflags",
 ]
 
 [[package]]
 name = "wgpu_glyph"
-version = "0.10.0"
+version = "0.11.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "27812a263e1298d3330795af62faf5daf5852beb632794acf93e4494234fc9f4"
+checksum = "354c1f79e09923724a6006a6953c3946522b84f7a9ec202b7e8001f274fd4bd5"
 dependencies = [
+ "bytemuck",
  "glyph_brush",
  "log",
  "wgpu",
- "zerocopy",
 ]
 
 [[package]]
@@ -4237,14 +4327,14 @@ checksum = "712e227841d057c1ee1cd2fb22fa7e5a5461ae8e48fa2ca79ec42cfc1931183f"
 
 [[package]]
 name = "winit"
-version = "0.22.2"
+version = "0.24.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1e4ccbf7ddb6627828eace16cacde80fc6bf4dbb3469f88487262a02cf8e7862"
+checksum = "da4eda6fce0eb84bd0a33e3c8794eb902e1033d0a1d5a31bc4f19b1b4bbff597"
 dependencies = [
  "bitflags",
  "cocoa",
- "core-foundation 0.7.0",
- "core-graphics",
+ "core-foundation 0.9.1",
+ "core-graphics 0.22.2",
  "core-video-sys",
  "dispatch",
  "instant",
@@ -4257,11 +4347,11 @@ dependencies = [
  "ndk-glue",
  "ndk-sys",
  "objc",
- "parking_lot 0.10.2",
+ "parking_lot",
  "percent-encoding",
  "raw-window-handle",
- "smithay-client-toolkit 0.6.6",
- "wayland-client 0.23.6",
+ "smithay-client-toolkit",
+ "wayland-client",
  "winapi 0.3.9",
  "x11-dl",
 ]
@@ -4294,16 +4384,6 @@ dependencies = [
  "rand_core 0.4.2",
 ]
 
-[[package]]
-name = "x11"
-version = "2.18.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "77ecd092546cb16f25783a5451538e73afc8d32e242648d54f4ae5459ba1e773"
-dependencies = [
- "libc",
- "pkg-config",
-]
-
 [[package]]
 name = "x11-clipboard"
 version = "0.5.1"
diff --git a/editor/Cargo.toml b/editor/Cargo.toml
index 6adf1f8e77..b2a89fa2ac 100644
--- a/editor/Cargo.toml
+++ b/editor/Cargo.toml
@@ -19,29 +19,29 @@ roc_fmt = { path = "../compiler/fmt" }
 
  # TODO switch to clap 3.0.0 once it's out. Tried adding clap = "~3.0.0-beta.1" and cargo wouldn't accept it
 ven_graph = { path = "../vendor/pathfinding" }
-im    = "14" # im and im-rc should always have the same version!
-im-rc = "14" # im and im-rc should always have the same version!
+im    = "15" # im and im-rc should always have the same version!
+im-rc = "15" # im and im-rc should always have the same version!
 bumpalo = { version = "3.2", features = ["collections"] }
 inlinable_string = "0.1"
 arraystring = "0.3.0"
 libc = "0.2"
 page_size = "0.4"
-winit = "0.22"
-wgpu = "0.6"
+winit = "0.24"
+wgpu = "0.7"
 glyph_brush = "0.7"
 log = "0.4"
 zerocopy = "0.3"
-env_logger = "0.7"
+env_logger = "0.8"
 futures = "0.3"
-wgpu_glyph = "0.10"
-cgmath = "0.17.0"
+wgpu_glyph = "0.11"
+cgmath = "0.18.0"
 snafu = { version = "0.6", features = ["backtraces"] }
 colored = "2"
 pest = "2.1"
 pest_derive = "2.1"
 ropey = "1.2.0"
 copypasta = "0.7.1"
-indoc = "0.3.3"
+indoc = "1.0"
 palette = "0.5"
 
 [dependencies.bytemuck]
@@ -49,10 +49,10 @@ version = "1.4"
 features = ["derive"]
 
 [dev-dependencies]
-pretty_assertions = "0.5.1"
+pretty_assertions = "0.6"
 maplit = "1.0.1"
-quickcheck = "0.8"
-quickcheck_macros = "0.8"
+quickcheck = "1.0"
+quickcheck_macros = "1.0"
 criterion = "0.3"
 rand = "0.8.2"
 
diff --git a/editor/editor-ideas.md b/editor/editor-ideas.md
index dadfc4c4ac..af93a2be73 100644
--- a/editor/editor-ideas.md
+++ b/editor/editor-ideas.md
@@ -64,7 +64,8 @@ e.g. you have a test `calculate_sum_test` that only uses the function `add`, whe
 
 * When refactoring; 
     - Cutting and pasting code to a new file should automatically add imports to the new file and delete them from the old file.
-    - Ability to link e.g. variable name in comments to actual variable name. Comment is automatically updated when variable name is changed. 
+    - Ability to link e.g. variable name in comments to actual variable name. Comment is automatically updated when variable name is changed.
+    - When updating dependencies with breaking changes; show similar diffs from github projects that have succesfully updated that dependency.
 * Automatically create all "arms" when pattern matching after entering `when var is` based on the type.
     - All `when ... is` should be updated if the type is changed, e.g. adding Indigo to the Color type should add an arm everywhere where `when color is` is used. 
 * When a function is called like `foo(false)`, the name of the boolean argument should be shown automatically; `foo(`*is_active:*`false)`. This should be done for booleans and numbers.
diff --git a/editor/src/editor/main.rs b/editor/src/editor/main.rs
index 5ddc264a02..cfaca9baaa 100644
--- a/editor/src/editor/main.rs
+++ b/editor/src/editor/main.rs
@@ -88,9 +88,9 @@ fn run_event_loop(file_path_opt: Option<&Path>) -> Result<(), Box<dyn Error>> {
         adapter
             .request_device(
                 &wgpu::DeviceDescriptor {
+                    label: None,
                     features: wgpu::Features::empty(),
                     limits: wgpu::Limits::default(),
-                    shader_validation: false,
                 },
                 None,
             )
@@ -108,12 +108,12 @@ fn run_event_loop(file_path_opt: Option<&Path>) -> Result<(), Box<dyn Error>> {
     let mut size = window.inner_size();
 
     let swap_chain_descr = wgpu::SwapChainDescriptor {
-        usage: wgpu::TextureUsage::OUTPUT_ATTACHMENT,
+        usage: wgpu::TextureUsage::RENDER_ATTACHMENT,
         format: render_format,
         width: size.width,
         height: size.height,
-        //Immediate may cause tearing, change present_mode if this becomes a problem
-        present_mode: wgpu::PresentMode::Immediate,
+        // TODO go back to Immediate
+        present_mode: wgpu::PresentMode::Fifo,
     };
 
     let mut swap_chain = gpu_device.create_swap_chain(&surface, &swap_chain_descr);
@@ -182,12 +182,12 @@ fn run_event_loop(file_path_opt: Option<&Path>) -> Result<(), Box<dyn Error>> {
                 swap_chain = gpu_device.create_swap_chain(
                     &surface,
                     &wgpu::SwapChainDescriptor {
-                        usage: wgpu::TextureUsage::OUTPUT_ATTACHMENT,
+                        usage: wgpu::TextureUsage::RENDER_ATTACHMENT,
                         format: render_format,
                         width: size.width,
                         height: size.height,
-                        //Immediate may cause tearing, change present_mode if this becomes a problem
-                        present_mode: wgpu::PresentMode::Immediate,
+                        // TODO go back to Immediate
+                        present_mode: wgpu::PresentMode::Fifo,
                     },
                 );
 
@@ -376,7 +376,10 @@ fn draw_all_rects(
         render_pass.set_pipeline(&rect_resources.pipeline);
         render_pass.set_bind_group(0, &rect_resources.ortho.bind_group, &[]);
         render_pass.set_vertex_buffer(0, rect_buffers.vertex_buffer.slice(..));
-        render_pass.set_index_buffer(rect_buffers.index_buffer.slice(..));
+        render_pass.set_index_buffer(
+            rect_buffers.index_buffer.slice(..),
+            wgpu::IndexFormat::Uint32,
+        );
         render_pass.draw_indexed(0..rect_buffers.num_rects, 0, 0..1);
     } else {
         // need to begin render pass to clear screen
@@ -403,25 +406,26 @@ fn begin_render_pass<'a>(
             },
         }],
         depth_stencil_attachment: None,
+        label: None,
     })
 }
 
 fn queue_editor_text(
     size: &PhysicalSize<u32>,
-    _editor_lines: &str,
+    editor_lines: &str,
     caret_pos: TextPos,
     config: &Config,
     glyph_brush: &mut GlyphBrush<()>,
 ) {
     let area_bounds = (size.width as f32, size.height as f32).into();
 
-    // let code_text = Text {
-    //     position: CODE_TXT_XY.into(),
-    //     area_bounds,
-    //     text: editor_lines,
-    //     size: settings.code_font_size,
-    //     ..Default::default()
-    // };
+    let code_text = Text {
+        position: CODE_TXT_XY.into(),
+        area_bounds,
+        text: editor_lines,
+        size: config.code_font_size,
+        ..Default::default()
+    };
 
     let s = format!("Ln {}, Col {}", caret_pos.line, caret_pos.column);
     let text = s.as_str();
@@ -438,7 +442,7 @@ fn queue_editor_text(
     queue_text_draw(&caret_pos_label, glyph_brush);
 
     // TODO convert to ast and render with render_ast::render_expr2
-    //queue_code_text_draw(&code_text, &ed_theme.syntax_high_map, settings, glyph_brush);
+    queue_text_draw(&code_text, glyph_brush);
 }
 
 fn _queue_no_file_text(
diff --git a/editor/src/graphics/lowlevel/ortho.rs b/editor/src/graphics/lowlevel/ortho.rs
index 115fd24a11..c3bcab80bb 100644
--- a/editor/src/graphics/lowlevel/ortho.rs
+++ b/editor/src/graphics/lowlevel/ortho.rs
@@ -91,8 +91,9 @@ pub fn init_ortho(
         entries: &[BindGroupLayoutEntry {
             binding: 0,
             visibility: ShaderStage::VERTEX,
-            ty: wgpu::BindingType::UniformBuffer {
-                dynamic: false,
+            ty: wgpu::BindingType::Buffer {
+                ty: wgpu::BufferBindingType::Uniform,
+                has_dynamic_offset: false,
                 min_binding_size: None,
             },
             count: None,
@@ -104,7 +105,7 @@ pub fn init_ortho(
         layout: &ortho_bind_group_layout,
         entries: &[wgpu::BindGroupEntry {
             binding: 0,
-            resource: wgpu::BindingResource::Buffer(ortho_buffer.slice(..)),
+            resource: ortho_buffer.as_entire_binding(),
         }],
         label: Some("Ortho bind group"),
     });
diff --git a/editor/src/graphics/lowlevel/pipelines.rs b/editor/src/graphics/lowlevel/pipelines.rs
index 98b692fe30..9c5084b207 100644
--- a/editor/src/graphics/lowlevel/pipelines.rs
+++ b/editor/src/graphics/lowlevel/pipelines.rs
@@ -21,9 +21,8 @@ pub fn make_rect_pipeline(
         &gpu_device,
         &pipeline_layout,
         swap_chain_descr.format,
-        &[Vertex::DESC],
-        wgpu::include_spirv!("../shaders/rect.vert.spv"),
-        wgpu::include_spirv!("../shaders/rect.frag.spv"),
+        &wgpu::include_spirv!("../shaders/rect.vert.spv"),
+        &wgpu::include_spirv!("../shaders/rect.frag.spv"),
     );
 
     RectResources { pipeline, ortho }
@@ -33,9 +32,8 @@ pub fn create_render_pipeline(
     device: &wgpu::Device,
     layout: &wgpu::PipelineLayout,
     color_format: wgpu::TextureFormat,
-    vertex_descs: &[wgpu::VertexBufferDescriptor],
-    vs_src: wgpu::ShaderModuleSource,
-    fs_src: wgpu::ShaderModuleSource,
+    vs_src: &wgpu::ShaderModuleDescriptor,
+    fs_src: &wgpu::ShaderModuleDescriptor,
 ) -> wgpu::RenderPipeline {
     let vs_module = device.create_shader_module(vs_src);
     let fs_module = device.create_shader_module(fs_src);
@@ -43,29 +41,27 @@ pub fn create_render_pipeline(
     device.create_render_pipeline(&wgpu::RenderPipelineDescriptor {
         label: Some("Render pipeline"),
         layout: Some(&layout),
-        vertex_stage: wgpu::ProgrammableStageDescriptor {
+        vertex: wgpu::VertexState {
             module: &vs_module,
             entry_point: "main",
+            buffers: &[Vertex::DESC],
         },
-        fragment_stage: Some(wgpu::ProgrammableStageDescriptor {
+        fragment: Some(wgpu::FragmentState {
             module: &fs_module,
             entry_point: "main",
+            targets: &[wgpu::ColorTargetState {
+                format: color_format,
+                color_blend: wgpu::BlendState::REPLACE,
+                alpha_blend: wgpu::BlendState::REPLACE,
+                write_mask: wgpu::ColorWrite::ALL,
+            }],
         }),
-        rasterization_state: None,
-        primitive_topology: wgpu::PrimitiveTopology::TriangleList,
-        color_states: &[wgpu::ColorStateDescriptor {
-            format: color_format,
-            color_blend: wgpu::BlendDescriptor::REPLACE,
-            alpha_blend: wgpu::BlendDescriptor::REPLACE,
-            write_mask: wgpu::ColorWrite::ALL,
-        }],
-        depth_stencil_state: None,
-        sample_count: 1,
-        sample_mask: !0,
-        alpha_to_coverage_enabled: false,
-        vertex_state: wgpu::VertexStateDescriptor {
-            index_format: wgpu::IndexFormat::Uint32,
-            vertex_buffers: vertex_descs,
+        primitive: wgpu::PrimitiveState::default(),
+        depth_stencil: None,
+        multisample: wgpu::MultisampleState {
+            count: 1,
+            mask: !0,
+            alpha_to_coverage_enabled: false,
         },
     })
 }
diff --git a/editor/src/graphics/lowlevel/vertex.rs b/editor/src/graphics/lowlevel/vertex.rs
index 3b5274ce3f..1b6dd40c56 100644
--- a/editor/src/graphics/lowlevel/vertex.rs
+++ b/editor/src/graphics/lowlevel/vertex.rs
@@ -13,18 +13,18 @@ unsafe impl bytemuck::Zeroable for Vertex {}
 
 impl Vertex {
     pub const SIZE: wgpu::BufferAddress = std::mem::size_of::<Self>() as wgpu::BufferAddress;
-    pub const DESC: wgpu::VertexBufferDescriptor<'static> = wgpu::VertexBufferDescriptor {
-        stride: Self::SIZE,
+    pub const DESC: wgpu::VertexBufferLayout<'static> = wgpu::VertexBufferLayout {
+        array_stride: Self::SIZE,
         step_mode: wgpu::InputStepMode::Vertex,
         attributes: &[
             // position
-            wgpu::VertexAttributeDescriptor {
+            wgpu::VertexAttribute {
                 offset: 0,
                 shader_location: 0,
                 format: wgpu::VertexFormat::Float2,
             },
             // color
-            wgpu::VertexAttributeDescriptor {
+            wgpu::VertexAttribute {
                 offset: std::mem::size_of::<[f32; 2]>() as wgpu::BufferAddress,
                 shader_location: 1,
                 format: wgpu::VertexFormat::Float4,

From 502946982554ad7a3c8848d668f6d97c0b447754 Mon Sep 17 00:00:00 2001
From: Folkert <folkert@folkertdev.nl>
Date: Mon, 8 Mar 2021 15:48:22 +0100
Subject: [PATCH 03/74] optimize keyword parsing

---
 compiler/parse/src/parser.rs | 40 ++++++++++++++++--------------------
 1 file changed, 18 insertions(+), 22 deletions(-)

diff --git a/compiler/parse/src/parser.rs b/compiler/parse/src/parser.rs
index 56c93a324b..dc3c479e3c 100644
--- a/compiler/parse/src/parser.rs
+++ b/compiler/parse/src/parser.rs
@@ -1128,31 +1128,27 @@ where
     ToError: Fn(Row, Col) -> E,
     E: 'a,
 {
-    move |arena, state: State<'a>| {
-        let initial_state = state.clone();
-        // first parse the keyword characters
-        let (_, _, after_keyword_state) = ascii_string(keyword)
-            .parse(arena, state)
-            .map_err(|(_, _, state)| (NoProgress, if_error(state.line, state.column), state))?;
+    move |_, mut state: State<'a>| {
+        let width = keyword.len();
 
-        // then we must have at least one space character
-        // TODO this is potentially wasteful if there are a lot of spaces
-        match peek_utf8_char(&after_keyword_state) {
-            Ok((next, _width)) if next == ' ' || next == '#' || next == '\n' => {
-                // give back the state after parsing the keyword, but before the whitespace
-                // that way we can attach the whitespace to whatever follows
-                Ok((MadeProgress, (), after_keyword_state))
+        if !state.bytes.starts_with(keyword.as_bytes()) {
+            return Err((NoProgress, if_error(state.line, state.column), state));
+        }
+
+        // the next character should not be an identifier character
+        // to prevent treating `whence` or `iffy` as keywords
+        match state.bytes.get(width) {
+            Some(next) if *next == b' ' || *next == b'#' || *next == b'\n' => {
+                state.column += width as u16;
+                state.bytes = &state.bytes[width..];
+                Ok((MadeProgress, (), state))
             }
-            _ => {
-                // this is not a keyword, maybe it's `whence` or `iffy`
-                // anyway, make no progress and return the initial state
-                // so we can try something else
-                Err((
-                    NoProgress,
-                    if_error(initial_state.line, initial_state.column),
-                    initial_state,
-                ))
+            None => {
+                state.column += width as u16;
+                state.bytes = &state.bytes[width..];
+                Ok((MadeProgress, (), state))
             }
+            Some(_) => Err((NoProgress, if_error(state.line, state.column), state)),
         }
     }
 }

From 905301bf963ef4261b021dfa99a0b6b6c8d2608d Mon Sep 17 00:00:00 2001
From: Folkert <folkert@folkertdev.nl>
Date: Mon, 8 Mar 2021 15:48:40 +0100
Subject: [PATCH 04/74] start giving header parsing good messages

---
 compiler/parse/src/expr.rs         |  1 +
 compiler/parse/src/module.rs       | 50 +++++++++++++++++++++-----
 compiler/parse/src/parser.rs       | 58 ++++++++++++++++++++++++++++++
 compiler/parse/src/test_helpers.rs |  1 -
 4 files changed, 100 insertions(+), 10 deletions(-)

diff --git a/compiler/parse/src/expr.rs b/compiler/parse/src/expr.rs
index 18e70a736d..5780967d54 100644
--- a/compiler/parse/src/expr.rs
+++ b/compiler/parse/src/expr.rs
@@ -20,6 +20,7 @@ use roc_region::all::{Located, Region};
 
 use crate::parser::Progress::{self, *};
 
+// public for testing purposes
 pub fn expr<'a>(min_indent: u16) -> impl Parser<'a, Expr<'a>, SyntaxError<'a>> {
     // Recursive parsers must not directly invoke functions which return (impl Parser),
     // as this causes rustc to stack overflow. Thus, parse_expr must be a
diff --git a/compiler/parse/src/module.rs b/compiler/parse/src/module.rs
index 2a48a885fb..6b8ae2af12 100644
--- a/compiler/parse/src/module.rs
+++ b/compiler/parse/src/module.rs
@@ -1,5 +1,5 @@
 use crate::ast::{Attempting, CommentOrNewline, Def, Module};
-use crate::blankspace::{space0, space0_around, space0_before, space1};
+use crate::blankspace::{space0, space0_around, space0_before, space0_e, space1};
 use crate::expr::def;
 use crate::header::{
     package_entry, package_or_path, AppHeader, Effects, ExposesEntry, ImportsEntry,
@@ -10,7 +10,8 @@ use crate::ident::{lowercase_ident, unqualified_ident, uppercase_ident};
 use crate::parser::Progress::{self, *};
 use crate::parser::{
     self, ascii_char, ascii_string, backtrackable, end_of_file, loc, optional, peek_utf8_char,
-    peek_utf8_char_at, unexpected, unexpected_eof, Either, ParseResult, Parser, State, SyntaxError,
+    peek_utf8_char_at, specialize, unexpected, unexpected_eof, word1, EHeader, EProvides, Either,
+    ParseResult, Parser, State, SyntaxError,
 };
 use crate::string_literal;
 use crate::type_annotation;
@@ -382,18 +383,49 @@ fn provides_without_to<'a>() -> impl Parser<
     ),
     SyntaxError<'a>,
 > {
+    specialize(
+        |e, r, c| SyntaxError::Header(EHeader::Provides(e, r, c)),
+        provides_without_to_help(),
+    )
+}
+
+#[inline(always)]
+fn provides_without_to_help<'a>() -> impl Parser<
+    'a,
+    (
+        (&'a [CommentOrNewline<'a>], &'a [CommentOrNewline<'a>]),
+        Vec<'a, Located<ExposesEntry<'a, &'a str>>>,
+    ),
+    EProvides,
+> {
+    let min_indent = 1;
     and!(
-        and!(skip_second!(space1(1), ascii_string("provides")), space1(1)),
-        collection!(
-            ascii_char(b'['),
-            loc!(map!(unqualified_ident(), ExposesEntry::Exposed)),
-            ascii_char(b','),
-            ascii_char(b']'),
-            1
+        and!(
+            skip_second!(
+                space0_e(min_indent, EProvides::Space, EProvides::IndentKeyword),
+                crate::parser::keyword_e("provides", EProvides::Keyword)
+            ),
+            space0_e(min_indent, EProvides::Space, EProvides::IndentListStart)
+        ),
+        collection_e!(
+            word1(b'[', EProvides::ListStart),
+            exposes_entry(),
+            word1(b',', EProvides::ListEnd),
+            word1(b']', EProvides::ListEnd),
+            min_indent,
+            EProvides::Space,
+            EProvides::IndentListEnd
         )
     )
 }
 
+fn exposes_entry<'a>() -> impl Parser<'a, Located<ExposesEntry<'a, &'a str>>, EProvides> {
+    loc!(map!(
+        specialize(|_, r, c| EProvides::Identifier(r, c), unqualified_ident()),
+        ExposesEntry::Exposed
+    ))
+}
+
 #[inline(always)]
 fn requires<'a>() -> impl Parser<
     'a,
diff --git a/compiler/parse/src/parser.rs b/compiler/parse/src/parser.rs
index dc3c479e3c..5fb31c1f0d 100644
--- a/compiler/parse/src/parser.rs
+++ b/compiler/parse/src/parser.rs
@@ -334,9 +334,27 @@ pub enum SyntaxError<'a> {
     Type(Type<'a>),
     Pattern(EPattern<'a>),
     Expr(EExpr<'a>),
+    Header(EHeader),
     Space(BadInputError),
 }
 
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub enum EHeader {
+    Provides(EProvides, Row, Col),
+}
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub enum EProvides {
+    Keyword(Row, Col),
+    IndentKeyword(Row, Col),
+    IndentListStart(Row, Col),
+    IndentListEnd(Row, Col),
+    ListStart(Row, Col),
+    ListEnd(Row, Col),
+    Identifier(Row, Col),
+    Space(BadInputError, Row, Col),
+}
+
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
 pub enum BadInputError {
     HasTab,
@@ -1585,6 +1603,46 @@ macro_rules! collection {
     };
 }
 
+#[macro_export]
+macro_rules! collection_e {
+    ($opening_brace:expr, $elem:expr, $delimiter:expr, $closing_brace:expr, $min_indent:expr, $space_problem:expr, $indent_problem:expr) => {
+        skip_first!(
+            $opening_brace,
+            skip_first!(
+                // We specifically allow space characters inside here, so that
+                // `[  ]` can be successfully parsed as an empty list, and then
+                // changed by the formatter back into `[]`.
+                //
+                // We don't allow newlines or comments in the middle of empty
+                // roc_collections because those are normally stored in an Expr,
+                // and there's no Expr in which to store them in an empty collection!
+                //
+                // We could change the AST to add extra storage specifically to
+                // support empty literals containing newlines or comments, but this
+                // does not seem worth even the tiniest regression in compiler performance.
+                zero_or_more!($crate::parser::word1(b' ', |row, col| $space_problem(
+                    crate::parser::BadInputError::LineTooLong,
+                    row,
+                    col
+                ))),
+                skip_second!(
+                    $crate::parser::sep_by0(
+                        $delimiter,
+                        $crate::blankspace::space0_around_ee(
+                            $elem,
+                            $min_indent,
+                            $space_problem,
+                            $indent_problem,
+                            $indent_problem
+                        )
+                    ),
+                    $closing_brace
+                )
+            )
+        )
+    };
+}
+
 /// Parse zero or more elements between two braces (e.g. square braces).
 /// Elements can be optionally surrounded by spaces, and are separated by a
 /// delimiter (e.g comma-separated) with optionally a trailing delimiter.
diff --git a/compiler/parse/src/test_helpers.rs b/compiler/parse/src/test_helpers.rs
index e0ca22e765..ebfb5bb1af 100644
--- a/compiler/parse/src/test_helpers.rs
+++ b/compiler/parse/src/test_helpers.rs
@@ -7,7 +7,6 @@ use bumpalo::collections::Vec;
 use bumpalo::Bump;
 use roc_region::all::Located;
 
-#[allow(dead_code)]
 pub fn parse_expr_with<'a>(
     arena: &'a Bump,
     input: &'a str,

From 784e3ddac4a5dedee8bb2ede64426f254ffb6491 Mon Sep 17 00:00:00 2001
From: Folkert <folkert@folkertdev.nl>
Date: Mon, 8 Mar 2021 16:15:38 +0100
Subject: [PATCH 05/74] change provides ... to

---
 compiler/parse/src/module.rs | 69 +++++++++++++++++-------------------
 compiler/parse/src/parser.rs |  8 +++--
 2 files changed, 39 insertions(+), 38 deletions(-)

diff --git a/compiler/parse/src/module.rs b/compiler/parse/src/module.rs
index 6b8ae2af12..7815ce9615 100644
--- a/compiler/parse/src/module.rs
+++ b/compiler/parse/src/module.rs
@@ -3,14 +3,13 @@ use crate::blankspace::{space0, space0_around, space0_before, space0_e, space1};
 use crate::expr::def;
 use crate::header::{
     package_entry, package_or_path, AppHeader, Effects, ExposesEntry, ImportsEntry,
-    InterfaceHeader, ModuleName, PackageEntry, PackageName, PackageOrPath, PlatformHeader, To,
-    TypedIdent,
+    InterfaceHeader, ModuleName, PackageEntry, PackageName, PlatformHeader, To, TypedIdent,
 };
 use crate::ident::{lowercase_ident, unqualified_ident, uppercase_ident};
 use crate::parser::Progress::{self, *};
 use crate::parser::{
     self, ascii_char, ascii_string, backtrackable, end_of_file, loc, optional, peek_utf8_char,
-    peek_utf8_char_at, specialize, unexpected, unexpected_eof, word1, EHeader, EProvides, Either,
+    peek_utf8_char_at, specialize, unexpected, unexpected_eof, word1, EHeader, EProvides,
     ParseResult, Parser, State, SyntaxError,
 };
 use crate::string_literal;
@@ -322,46 +321,44 @@ struct ProvidesTo<'a> {
 
 #[inline(always)]
 fn provides_to<'a>() -> impl Parser<'a, ProvidesTo<'a>, SyntaxError<'a>> {
+    specialize(
+        |e, r, c| SyntaxError::Header(EHeader::Provides(e, r, c)),
+        provides_to_help(),
+    )
+}
+
+fn provides_to_package<'a>() -> impl Parser<'a, To<'a>, SyntaxError<'a>> {
+    one_of![
+        map!(lowercase_ident(), To::ExistingPackage),
+        map!(package_or_path(), To::NewPackage)
+    ]
+}
+
+#[inline(always)]
+fn provides_to_help<'a>() -> impl Parser<'a, ProvidesTo<'a>, EProvides> {
+    let min_indent = 1;
+
     map!(
         and!(
+            provides_without_to_help(),
             and!(
-                skip_second!(backtrackable(space1(1)), ascii_string("provides")),
-                space1(1)
-            ),
-            and!(
-                collection!(
-                    ascii_char(b'['),
-                    loc!(map!(unqualified_ident(), ExposesEntry::Exposed)),
-                    ascii_char(b','),
-                    ascii_char(b']'),
-                    1
-                ),
-                and!(
-                    space1(1),
-                    skip_first!(
-                        ascii_string("to"),
-                        and!(
-                            space1(1),
-                            loc!(either!(lowercase_ident(), package_or_path()))
-                        )
+                space0_e(min_indent, EProvides::Space, EProvides::IndentTo),
+                skip_first!(
+                    crate::parser::keyword_e("to", EProvides::To),
+                    and!(
+                        space0_e(min_indent, EProvides::Space, EProvides::IndentPackage),
+                        loc!(specialize(
+                            |_, r, c| EProvides::Package(r, c),
+                            provides_to_package()
+                        ))
                     )
                 )
             )
         ),
         |(
-            (before_provides_keyword, after_provides_keyword),
-            (entries, (before_to_keyword, (after_to_keyword, loc_to))),
+            ((before_provides_keyword, after_provides_keyword), entries),
+            (before_to_keyword, (after_to_keyword, to)),
         )| {
-            let loc_to: Located<Either<&'a str, PackageOrPath<'a>>> = loc_to;
-            let to_val = match loc_to.value {
-                Either::First(pkg) => To::ExistingPackage(pkg),
-                Either::Second(pkg) => To::NewPackage(pkg),
-            };
-            let to = Located {
-                value: to_val,
-                region: loc_to.region,
-            };
-
             ProvidesTo {
                 entries,
                 to,
@@ -402,8 +399,8 @@ fn provides_without_to_help<'a>() -> impl Parser<
     and!(
         and!(
             skip_second!(
-                space0_e(min_indent, EProvides::Space, EProvides::IndentKeyword),
-                crate::parser::keyword_e("provides", EProvides::Keyword)
+                space0_e(min_indent, EProvides::Space, EProvides::IndentProvides),
+                crate::parser::keyword_e("provides", EProvides::Provides)
             ),
             space0_e(min_indent, EProvides::Space, EProvides::IndentListStart)
         ),
diff --git a/compiler/parse/src/parser.rs b/compiler/parse/src/parser.rs
index 5fb31c1f0d..a16cb3bd9f 100644
--- a/compiler/parse/src/parser.rs
+++ b/compiler/parse/src/parser.rs
@@ -345,13 +345,17 @@ pub enum EHeader {
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
 pub enum EProvides {
-    Keyword(Row, Col),
-    IndentKeyword(Row, Col),
+    Provides(Row, Col),
+    To(Row, Col),
+    IndentProvides(Row, Col),
+    IndentTo(Row, Col),
     IndentListStart(Row, Col),
     IndentListEnd(Row, Col),
+    IndentPackage(Row, Col),
     ListStart(Row, Col),
     ListEnd(Row, Col),
     Identifier(Row, Col),
+    Package(Row, Col),
     Space(BadInputError, Row, Col),
 }
 

From 65cee3904127752591e8455ae4bfbd0465138290 Mon Sep 17 00:00:00 2001
From: Folkert <folkert@folkertdev.nl>
Date: Mon, 8 Mar 2021 16:33:45 +0100
Subject: [PATCH 06/74] remove attempting argument from parser state

---
 compiler/load/src/file.rs          | 6 +++---
 compiler/parse/src/parser.rs       | 2 +-
 compiler/parse/src/test_helpers.rs | 8 ++++----
 editor/src/lang/expr.rs            | 4 ++--
 editor/src/lang/roc_file.rs        | 4 ++--
 5 files changed, 12 insertions(+), 12 deletions(-)

diff --git a/compiler/load/src/file.rs b/compiler/load/src/file.rs
index dc0dc9ec12..7ae0aa7833 100644
--- a/compiler/load/src/file.rs
+++ b/compiler/load/src/file.rs
@@ -22,7 +22,7 @@ use roc_mono::ir::{
     CapturedSymbols, ExternalSpecializations, PartialProc, PendingSpecialization, Proc, Procs,
 };
 use roc_mono::layout::{Layout, LayoutCache, LayoutProblem};
-use roc_parse::ast::{self, Attempting, StrLiteral, TypeAnnotation};
+use roc_parse::ast::{self, StrLiteral, TypeAnnotation};
 use roc_parse::header::{
     ExposesEntry, ImportsEntry, PackageEntry, PackageOrPath, PlatformHeader, To, TypedIdent,
 };
@@ -2304,7 +2304,7 @@ fn load_pkg_config<'a>(
         Ok(bytes_vec) => {
             let parse_start = SystemTime::now();
             let bytes = arena.alloc(bytes_vec);
-            let parse_state = parser::State::new_in(arena, bytes, Attempting::Module);
+            let parse_state = parser::State::new_in(arena, bytes);
             let parsed = roc_parse::module::header().parse(&arena, parse_state);
             let parse_header_duration = parse_start.elapsed().unwrap();
 
@@ -2474,7 +2474,7 @@ fn parse_header<'a>(
     start_time: SystemTime,
 ) -> Result<(ModuleId, Msg<'a>), LoadingProblem<'a>> {
     let parse_start = SystemTime::now();
-    let parse_state = parser::State::new_in(arena, src_bytes, Attempting::Module);
+    let parse_state = parser::State::new_in(arena, src_bytes);
     let parsed = roc_parse::module::header().parse(&arena, parse_state);
     let parse_header_duration = parse_start.elapsed().unwrap();
 
diff --git a/compiler/parse/src/parser.rs b/compiler/parse/src/parser.rs
index a16cb3bd9f..1ab906ea70 100644
--- a/compiler/parse/src/parser.rs
+++ b/compiler/parse/src/parser.rs
@@ -43,7 +43,7 @@ pub enum Either<First, Second> {
 }
 
 impl<'a> State<'a> {
-    pub fn new_in(arena: &'a Bump, bytes: &'a [u8], _attempting: Attempting) -> State<'a> {
+    pub fn new_in(arena: &'a Bump, bytes: &'a [u8]) -> State<'a> {
         State {
             bytes,
             line: 0,
diff --git a/compiler/parse/src/test_helpers.rs b/compiler/parse/src/test_helpers.rs
index ebfb5bb1af..7cfddd8d8c 100644
--- a/compiler/parse/src/test_helpers.rs
+++ b/compiler/parse/src/test_helpers.rs
@@ -1,4 +1,4 @@
-use crate::ast::{self, Attempting};
+use crate::ast;
 use crate::blankspace::space0_before;
 use crate::expr::expr;
 use crate::module::{header, module_defs};
@@ -18,7 +18,7 @@ pub fn parse_header_with<'a>(
     arena: &'a Bump,
     input: &'a str,
 ) -> Result<ast::Module<'a>, SyntaxError<'a>> {
-    let state = State::new_in(arena, input.trim().as_bytes(), Attempting::Module);
+    let state = State::new_in(arena, input.trim().as_bytes());
     let answer = header().parse(arena, state);
 
     answer
@@ -31,7 +31,7 @@ pub fn parse_defs_with<'a>(
     arena: &'a Bump,
     input: &'a str,
 ) -> Result<Vec<'a, Located<ast::Def<'a>>>, SyntaxError<'a>> {
-    let state = State::new_in(arena, input.trim().as_bytes(), Attempting::Module);
+    let state = State::new_in(arena, input.trim().as_bytes());
     let answer = module_defs().parse(arena, state);
     answer
         .map(|(_, loc_expr, _)| loc_expr)
@@ -43,7 +43,7 @@ pub fn parse_loc_with<'a>(
     arena: &'a Bump,
     input: &'a str,
 ) -> Result<Located<ast::Expr<'a>>, SyntaxError<'a>> {
-    let state = State::new_in(arena, input.trim().as_bytes(), Attempting::Module);
+    let state = State::new_in(arena, input.trim().as_bytes());
     let parser = space0_before(loc(expr(0)), 0);
     let answer = parser.parse(&arena, state);
 
diff --git a/editor/src/lang/expr.rs b/editor/src/lang/expr.rs
index 061fc21495..410009bc2e 100644
--- a/editor/src/lang/expr.rs
+++ b/editor/src/lang/expr.rs
@@ -16,8 +16,8 @@ use roc_module::ident::ModuleName;
 use roc_module::low_level::LowLevel;
 use roc_module::operator::CalledVia;
 use roc_module::symbol::{IdentIds, ModuleId, ModuleIds, Symbol};
+use roc_parse::ast;
 use roc_parse::ast::StrLiteral;
-use roc_parse::ast::{self, Attempting};
 use roc_parse::blankspace::space0_before;
 use roc_parse::expr::expr;
 use roc_parse::parser::{loc, Parser, State, SyntaxError};
@@ -235,7 +235,7 @@ pub fn str_to_expr2<'a>(
     scope: &mut Scope,
     region: Region,
 ) -> Result<(Expr2, self::Output), SyntaxError<'a>> {
-    let state = State::new_in(arena, input.trim().as_bytes(), Attempting::Module);
+    let state = State::new_in(arena, input.trim().as_bytes());
     let parser = space0_before(loc(expr(0)), 0);
     let parse_res = parser.parse(&arena, state);
 
diff --git a/editor/src/lang/roc_file.rs b/editor/src/lang/roc_file.rs
index 676c74048b..f034a1f1b0 100644
--- a/editor/src/lang/roc_file.rs
+++ b/editor/src/lang/roc_file.rs
@@ -2,7 +2,7 @@ use bumpalo::collections::Vec;
 use bumpalo::Bump;
 use roc_fmt::def::fmt_def;
 use roc_fmt::module::fmt_module;
-use roc_parse::ast::{Attempting, Def, Module};
+use roc_parse::ast::{Def, Module};
 use roc_parse::module::module_defs;
 use roc_parse::parser;
 use roc_parse::parser::{Parser, SyntaxError};
@@ -36,7 +36,7 @@ impl<'a> File<'a> {
 
         let allocation = arena.alloc(bytes);
 
-        let module_parse_state = parser::State::new_in(arena, allocation, Attempting::Module);
+        let module_parse_state = parser::State::new_in(arena, allocation);
         let parsed_module = roc_parse::module::header().parse(&arena, module_parse_state);
 
         match parsed_module {

From 25e3ab5a7d8879deedd46bbcb19707bca094face Mon Sep 17 00:00:00 2001
From: Folkert <folkert@folkertdev.nl>
Date: Mon, 8 Mar 2021 16:51:45 +0100
Subject: [PATCH 07/74] setup test infra

---
 compiler/reporting/tests/helpers/mod.rs    |  4 +-
 compiler/reporting/tests/test_reporting.rs | 82 ++++++++++++++++++++++
 2 files changed, 84 insertions(+), 2 deletions(-)

diff --git a/compiler/reporting/tests/helpers/mod.rs b/compiler/reporting/tests/helpers/mod.rs
index 7bc49f0421..2247be164c 100644
--- a/compiler/reporting/tests/helpers/mod.rs
+++ b/compiler/reporting/tests/helpers/mod.rs
@@ -11,7 +11,7 @@ use roc_collections::all::{ImMap, MutMap, SendSet};
 use roc_constrain::expr::constrain_expr;
 use roc_constrain::module::{constrain_imported_values, Import};
 use roc_module::symbol::{IdentIds, Interns, ModuleId, ModuleIds};
-use roc_parse::ast::{self, Attempting};
+use roc_parse::ast;
 use roc_parse::blankspace::space0_before;
 use roc_parse::parser::{loc, Parser, State, SyntaxError};
 use roc_problem::can::Problem;
@@ -110,7 +110,7 @@ pub fn parse_loc_with<'a>(
     arena: &'a Bump,
     input: &'a str,
 ) -> Result<Located<ast::Expr<'a>>, SyntaxError<'a>> {
-    let state = State::new_in(arena, input.trim().as_bytes(), Attempting::Module);
+    let state = State::new_in(arena, input.trim().as_bytes());
     let parser = space0_before(loc(roc_parse::expr::expr(0)), 0);
     let answer = parser.parse(&arena, state);
 
diff --git a/compiler/reporting/tests/test_reporting.rs b/compiler/reporting/tests/test_reporting.rs
index f4bd0aca8b..c73c168c55 100644
--- a/compiler/reporting/tests/test_reporting.rs
+++ b/compiler/reporting/tests/test_reporting.rs
@@ -169,6 +169,36 @@ mod test_reporting {
         }
     }
 
+    fn list_header_reports<F>(arena: &Bump, src: &str, buf: &mut String, callback: F)
+    where
+        F: FnOnce(RocDocBuilder<'_>, &mut String),
+    {
+        use ven_pretty::DocAllocator;
+
+        use roc_parse::parser::State;
+
+        let state = State::new_in(arena, src.as_bytes());
+
+        let filename = filename_from_string(r"\code\proj\Main.roc");
+        let src_lines: Vec<&str> = src.split('\n').collect();
+
+        use roc_parse::parser::Parser;
+        match roc_parse::module::header().parse(arena, state) {
+            Err((_, fail, _)) => {
+                let interns = Interns::default();
+                let home = crate::helpers::test_home();
+
+                let alloc = RocDocAllocator::new(&src_lines, home, &interns);
+
+                let problem = fail.into_parse_problem(filename.clone(), src.as_bytes());
+                let doc = parse_problem(&alloc, filename, 0, problem);
+
+                callback(doc.pretty(&alloc).append(alloc.line()), buf)
+            }
+            Ok(_) => todo!(),
+        }
+    }
+
     fn report_problem_as(src: &str, expected_rendering: &str) {
         let mut buf: String = String::new();
         let arena = Bump::new();
@@ -193,6 +223,30 @@ mod test_reporting {
         assert_eq!(buf, expected_rendering);
     }
 
+    fn report_header_problem_as(src: &str, expected_rendering: &str) {
+        let mut buf: String = String::new();
+        let arena = Bump::new();
+
+        let callback = |doc: RocDocBuilder<'_>, buf: &mut String| {
+            doc.1
+                .render_raw(70, &mut roc_reporting::report::CiWrite::new(buf))
+                .expect("list_reports")
+        };
+
+        list_header_reports(&arena, src, &mut buf, callback);
+
+        // convenient to copy-paste the generated message
+        if true {
+            if buf != expected_rendering {
+                for line in buf.split("\n") {
+                    println!("                {}", line);
+                }
+            }
+        }
+
+        assert_eq!(buf, expected_rendering);
+    }
+
     fn color_report_problem_as(src: &str, expected_rendering: &str) {
         let mut buf: String = String::new();
         let arena = Bump::new();
@@ -5702,4 +5756,32 @@ mod test_reporting {
             ),
         )
     }
+
+    #[test]
+    fn provides_to() {
+        // this is still bad, but changing the order and progress of other parsers should improve it
+        // down the line
+        report_header_problem_as(
+            indoc!(
+                r#"
+                app "test-base64"
+                    packages { base: "platform" }
+                    imports [base.Task, Base64 ]
+                    provides [ main, ## ] to base
+                "#
+            ),
+            indoc!(
+                r#"
+                ── MISSING EXPRESSION ──────────────────────────────────────────────────────────
+
+                I am partway through parsing a definition, but I got stuck here:
+
+                1│  main = 5 -> 3
+                              ^
+
+                I was expecting to see an expression like 42 or "hello".
+            "#
+            ),
+        )
+    }
 }

From 845307f94eb0b8233d964dfdeb11cdc24eb94fe1 Mon Sep 17 00:00:00 2001
From: Folkert <folkert@folkertdev.nl>
Date: Mon, 8 Mar 2021 19:20:11 +0100
Subject: [PATCH 08/74] first header parse report test

---
 compiler/parse/src/module.rs               |  2 +-
 compiler/reporting/src/error/parse.rs      | 57 ++++++++++++++++++++++
 compiler/reporting/tests/test_reporting.rs | 21 ++++----
 3 files changed, 70 insertions(+), 10 deletions(-)

diff --git a/compiler/parse/src/module.rs b/compiler/parse/src/module.rs
index 7815ce9615..40a6dd1014 100644
--- a/compiler/parse/src/module.rs
+++ b/compiler/parse/src/module.rs
@@ -308,7 +308,7 @@ pub fn module_defs<'a>() -> impl Parser<'a, Vec<'a, Located<Def<'a>>>, SyntaxErr
     // force that we pare until the end of the input
     skip_second!(zero_or_more!(space0_around(loc(def(0)), 0)), end_of_file())
 }
-
+#[derive(Debug)]
 struct ProvidesTo<'a> {
     entries: Vec<'a, Located<ExposesEntry<'a, &'a str>>>,
     to: Located<To<'a>>,
diff --git a/compiler/reporting/src/error/parse.rs b/compiler/reporting/src/error/parse.rs
index c9a412aac7..8e2dca66a3 100644
--- a/compiler/reporting/src/error/parse.rs
+++ b/compiler/reporting/src/error/parse.rs
@@ -153,6 +153,7 @@ fn to_syntax_report<'a>(
             0,
             0,
         ),
+        Header(header) => to_header_report(alloc, filename, &header, 0, 0),
         _ => todo!("unhandled parse error: {:?}", parse_problem),
     }
 }
@@ -2469,6 +2470,62 @@ fn to_tapply_report<'a>(
     }
 }
 
+fn to_header_report<'a>(
+    alloc: &'a RocDocAllocator<'a>,
+    filename: PathBuf,
+    parse_problem: &roc_parse::parser::EHeader,
+    _start_row: Row,
+    _start_col: Col,
+) -> Report<'a> {
+    use roc_parse::parser::EHeader;
+
+    match *parse_problem {
+        EHeader::Provides(provides, row, col) => {
+            to_provides_report(alloc, filename, &provides, row, col)
+        } // _ => todo!("unhandled parse error {:?}", parse_problem),
+    }
+}
+
+fn to_provides_report<'a>(
+    alloc: &'a RocDocAllocator<'a>,
+    filename: PathBuf,
+    parse_problem: &roc_parse::parser::EProvides,
+    start_row: Row,
+    start_col: Col,
+) -> Report<'a> {
+    use roc_parse::parser::EProvides;
+
+    match *parse_problem {
+        EProvides::Identifier(row, col) => {
+            let surroundings = Region::from_rows_cols(start_row, start_col, row, col);
+            let region = Region::from_row_col(row, col);
+
+            let doc = alloc.stack(vec![
+                alloc.reflow(
+                    r"I am in the middle of parsing a provides list, but I got stuck here:",
+                ),
+                alloc.region_with_subregion(surroundings, region),
+                alloc.concat(vec![alloc.reflow(
+                    "I was expecting a type name, value name or function name next, like ",
+                )]),
+                alloc
+                    .parser_suggestion("provides [ Animal, default, tame ]")
+                    .indent(4),
+            ]);
+
+            Report {
+                filename,
+                doc,
+                title: "WEIRD PROVIDES".to_string(),
+            }
+        }
+
+        EProvides::Space(error, row, col) => to_space_report(alloc, filename, &error, row, col),
+
+        _ => todo!("unhandled parse error {:?}", parse_problem),
+    }
+}
+
 fn to_space_report<'a>(
     alloc: &'a RocDocAllocator<'a>,
     filename: PathBuf,
diff --git a/compiler/reporting/tests/test_reporting.rs b/compiler/reporting/tests/test_reporting.rs
index c73c168c55..2980c65927 100644
--- a/compiler/reporting/tests/test_reporting.rs
+++ b/compiler/reporting/tests/test_reporting.rs
@@ -5767,19 +5767,22 @@ mod test_reporting {
                 app "test-base64"
                     packages { base: "platform" }
                     imports [base.Task, Base64 ]
-                    provides [ main, ## ] to base
+                    provides [ main, @Foo ] to base
                 "#
             ),
             indoc!(
                 r#"
-                ── MISSING EXPRESSION ──────────────────────────────────────────────────────────
-
-                I am partway through parsing a definition, but I got stuck here:
-
-                1│  main = 5 -> 3
-                              ^
-
-                I was expecting to see an expression like 42 or "hello".
+                ── WEIRD PROVIDES ──────────────────────────────────────────────────────────────
+                
+                I am in the middle of parsing a provides list, but I got stuck here:
+                
+                3│      imports [base.Task, Base64 ]
+                4│      provides [ main, @Foo ] to base
+                                         ^
+                
+                I was expecting a type name, value name or function name next, like 
+                
+                    provides [ Animal, default, tame ]
             "#
             ),
         )

From 8b9804adc2c1b00b51c110298aafe6988ad94238 Mon Sep 17 00:00:00 2001
From: Folkert <folkert@folkertdev.nl>
Date: Mon, 8 Mar 2021 21:14:47 +0100
Subject: [PATCH 09/74] generalize

---
 compiler/parse/src/module.rs | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/compiler/parse/src/module.rs b/compiler/parse/src/module.rs
index 40a6dd1014..fdc9aede9d 100644
--- a/compiler/parse/src/module.rs
+++ b/compiler/parse/src/module.rs
@@ -406,7 +406,7 @@ fn provides_without_to_help<'a>() -> impl Parser<
         ),
         collection_e!(
             word1(b'[', EProvides::ListStart),
-            exposes_entry(),
+            exposes_entry(EProvides::Identifier),
             word1(b',', EProvides::ListEnd),
             word1(b']', EProvides::ListEnd),
             min_indent,
@@ -416,9 +416,16 @@ fn provides_without_to_help<'a>() -> impl Parser<
     )
 }
 
-fn exposes_entry<'a>() -> impl Parser<'a, Located<ExposesEntry<'a, &'a str>>, EProvides> {
+fn exposes_entry<'a, F, E>(
+    to_expectation: F,
+) -> impl Parser<'a, Located<ExposesEntry<'a, &'a str>>, E>
+where
+    F: Fn(crate::parser::Row, crate::parser::Col) -> E,
+    F: Copy,
+    E: 'a,
+{
     loc!(map!(
-        specialize(|_, r, c| EProvides::Identifier(r, c), unqualified_ident()),
+        specialize(|_, r, c| to_expectation(r, c), unqualified_ident()),
         ExposesEntry::Exposed
     ))
 }

From 268ab8241004c60ecaf9f494d7022b383e16dffc Mon Sep 17 00:00:00 2001
From: rvcas <x@rvcas.dev>
Date: Mon, 8 Mar 2021 21:12:19 -0500
Subject: [PATCH 10/74] feat(List): add map3

---
 compiler/builtins/bitcode/src/list.zig | 121 +++++++++++++++++++++++++
 compiler/builtins/src/bitcode.rs       |   1 +
 compiler/builtins/src/std.rs           |  15 +++
 compiler/can/src/builtins.rs           |  39 ++++++++
 compiler/gen/src/llvm/build.rs         |  36 +++++++-
 compiler/gen/src/llvm/build_list.rs    | 108 ++++++++++++++++++++++
 compiler/module/src/low_level.rs       |   1 +
 compiler/module/src/symbol.rs          |   1 +
 compiler/mono/src/borrow.rs            |   1 +
 compiler/test_gen/src/gen_list.rs      |  30 ++++++
 10 files changed, 351 insertions(+), 2 deletions(-)

diff --git a/compiler/builtins/bitcode/src/list.zig b/compiler/builtins/bitcode/src/list.zig
index fcd5f42cf8..95137d25bb 100644
--- a/compiler/builtins/bitcode/src/list.zig
+++ b/compiler/builtins/bitcode/src/list.zig
@@ -114,6 +114,7 @@ pub const RocList = extern struct {
 
 const Caller1 = fn (?[*]u8, ?[*]u8, ?[*]u8) callconv(.C) void;
 const Caller2 = fn (?[*]u8, ?[*]u8, ?[*]u8, ?[*]u8) callconv(.C) void;
+const Caller3 = fn (?[*]u8, ?[*]u8, ?[*]u8, ?[*]u8, ?[*]u8) callconv(.C) void;
 
 pub fn listMap(list: RocList, transform: Opaque, caller: Caller1, alignment: usize, old_element_width: usize, new_element_width: usize) callconv(.C) RocList {
     if (list.bytes) |source_ptr| {
@@ -213,6 +214,126 @@ pub fn listMap2(list1: RocList, list2: RocList, transform: Opaque, caller: Calle
     }
 }
 
+pub fn listMap3(list1: RocList, list2: RocList, list3: RocList, transform: Opaque, caller: Caller3, alignment: usize, a_width: usize, b_width: usize, c_width: usize, d_width: usize, dec_a: Dec, dec_b: Dec, dec_c: Dec) callconv(.C) RocList {
+    const smaller_length = std.math.min(list1.len(), list2.len());
+    const output_length = std.math.min(smaller_length, list3.len());
+
+    if (list1.bytes) |source_a| {
+        if (list2.bytes) |source_b| {
+            if (list3.bytes) |source_c| {
+                const output = RocList.allocate(std.heap.c_allocator, alignment, output_length, d_width);
+                const target_ptr = output.bytes orelse unreachable;
+
+                var i: usize = 0;
+                while (i < output_length) : (i += 1) {
+                    const element_a = source_a + i * a_width;
+                    const element_b = source_b + i * b_width;
+                    const element_c = source_c + i * c_width;
+                    const target = target_ptr + i * d_width;
+
+                    caller(transform, element_a, element_b, element_c, target);
+                }
+
+                // if the lists don't have equal length, we must consume the remaining elements
+                // In this case we consume by (recursively) decrementing the elements
+                if (list1.len() > output_length) {
+                    while (i < list1.len()) : (i += 1) {
+                        const element_a = source_a + i * a_width;
+                        dec_a(element_a);
+                    }
+                }
+
+                if (list2.len() > output_length) {
+                    while (i < list2.len()) : (i += 1) {
+                        const element_b = source_b + i * b_width;
+                        dec_b(element_b);
+                    }
+                }
+
+                if (list3.len() > output_length) {
+                    while (i < list3.len()) : (i += 1) {
+                        const element_c = source_c + i * c_width;
+                        dec_b(element_c);
+                    }
+                }
+
+                utils.decref(std.heap.c_allocator, alignment, list1.bytes, list1.len() * a_width);
+                utils.decref(std.heap.c_allocator, alignment, list2.bytes, list2.len() * b_width);
+                utils.decref(std.heap.c_allocator, alignment, list3.bytes, list3.len() * c_width);
+
+                return output;
+            } else {
+                // consume list1 elements (we know there is at least one because the list1.bytes pointer is non-null
+                var i: usize = 0;
+                while (i < list1.len()) : (i += 1) {
+                    const element_a = source_a + i * a_width;
+                    dec_a(element_a);
+                }
+                utils.decref(std.heap.c_allocator, alignment, list1.bytes, list1.len() * a_width);
+
+                // consume list2 elements (we know there is at least one because the list1.bytes pointer is non-null
+                i = 0;
+                while (i < list2.len()) : (i += 1) {
+                    const element_b = source_b + i * b_width;
+                    dec_b(element_b);
+                }
+                utils.decref(std.heap.c_allocator, alignment, list2.bytes, list2.len() * b_width);
+
+                return RocList.empty();
+            }
+        } else {
+            // consume list1 elements (we know there is at least one because the list1.bytes pointer is non-null
+            var i: usize = 0;
+            while (i < list1.len()) : (i += 1) {
+                const element_a = source_a + i * a_width;
+                dec_a(element_a);
+            }
+
+            utils.decref(std.heap.c_allocator, alignment, list1.bytes, list1.len() * a_width);
+
+            // consume list3 elements (if any)
+            if (list3.bytes) |source_c| {
+                i = 0;
+
+                while (i < list2.len()) : (i += 1) {
+                    const element_c = source_c + i * c_width;
+                    dec_c(element_c);
+                }
+
+                utils.decref(std.heap.c_allocator, alignment, list3.bytes, list3.len() * c_width);
+            }
+
+            return RocList.empty();
+        }
+    } else {
+        // consume list2 elements (if any)
+        if (list2.bytes) |source_b| {
+            var i: usize = 0;
+
+            while (i < list2.len()) : (i += 1) {
+                const element_b = source_b + i * b_width;
+                dec_b(element_b);
+            }
+
+            utils.decref(std.heap.c_allocator, alignment, list2.bytes, list2.len() * b_width);
+        }
+
+        // consume list3 elements (if any)
+        if (list3.bytes) |source_c| {
+            var i: usize = 0;
+
+            while (i < list2.len()) : (i += 1) {
+                const element_c = source_c + i * c_width;
+                dec_c(element_c);
+            }
+
+            utils.decref(std.heap.c_allocator, alignment, list3.bytes, list3.len() * c_width);
+        }
+
+        return RocList.empty();
+    }
+}
+
 pub fn listKeepIf(list: RocList, transform: Opaque, caller: Caller1, alignment: usize, element_width: usize, inc: Inc, dec: Dec) callconv(.C) RocList {
     if (list.bytes) |source_ptr| {
         const size = list.len();
diff --git a/compiler/builtins/src/bitcode.rs b/compiler/builtins/src/bitcode.rs
index 2905ec52df..0fd6cb1f2f 100644
--- a/compiler/builtins/src/bitcode.rs
+++ b/compiler/builtins/src/bitcode.rs
@@ -64,6 +64,7 @@ pub const SET_FROM_LIST: &str = "roc_builtins.dict.set_from_list";
 
 pub const LIST_MAP: &str = "roc_builtins.list.map";
 pub const LIST_MAP2: &str = "roc_builtins.list.map2";
+pub const LIST_MAP3: &str = "roc_builtins.list.map3";
 pub const LIST_MAP_WITH_INDEX: &str = "roc_builtins.list.map_with_index";
 pub const LIST_KEEP_IF: &str = "roc_builtins.list.keep_if";
 pub const LIST_KEEP_OKS: &str = "roc_builtins.list.keep_oks";
diff --git a/compiler/builtins/src/std.rs b/compiler/builtins/src/std.rs
index 094fbac48f..a743afde77 100644
--- a/compiler/builtins/src/std.rs
+++ b/compiler/builtins/src/std.rs
@@ -817,6 +817,21 @@ pub fn types() -> MutMap<Symbol, (SolvedType, Region)> {
         )
     });
 
+    // map3 : List a, List b, List c, (a, b, c -> d) -> List d
+    add_type(Symbol::LIST_MAP3, {
+        let_tvars! {a, b, c, d, cvar};
+
+        top_level_function(
+            vec![
+                list_type(flex(a)),
+                list_type(flex(b)),
+                list_type(flex(c)),
+                closure(vec![flex(a), flex(b), flex(c)], cvar, Box::new(flex(d))),
+            ],
+            Box::new(list_type(flex(d))),
+        )
+    });
+
     // append : List elem, elem -> List elem
     add_type(
         Symbol::LIST_APPEND,
diff --git a/compiler/can/src/builtins.rs b/compiler/can/src/builtins.rs
index 6977eaa607..e31d1597f0 100644
--- a/compiler/can/src/builtins.rs
+++ b/compiler/can/src/builtins.rs
@@ -81,6 +81,7 @@ pub fn builtin_defs_map(symbol: Symbol, var_store: &mut VarStore) -> Option<Def>
         LIST_JOIN => list_join,
         LIST_MAP => list_map,
         LIST_MAP2 => list_map2,
+        LIST_MAP3 => list_map3,
         LIST_MAP_WITH_INDEX => list_map_with_index,
         LIST_KEEP_IF => list_keep_if,
         LIST_KEEP_OKS => list_keep_oks,
@@ -218,6 +219,7 @@ pub fn builtin_defs(var_store: &mut VarStore) -> MutMap<Symbol, Def> {
         Symbol::LIST_JOIN => list_join,
         Symbol::LIST_MAP => list_map,
         Symbol::LIST_MAP2 => list_map2,
+        Symbol::LIST_MAP3 => list_map3,
         Symbol::LIST_MAP_WITH_INDEX => list_map_with_index,
         Symbol::LIST_KEEP_IF => list_keep_if,
         Symbol::LIST_KEEP_OKS => list_keep_oks,
@@ -370,6 +372,38 @@ fn lowlevel_3(symbol: Symbol, op: LowLevel, var_store: &mut VarStore) -> Def {
     )
 }
 
+fn lowlevel_4(symbol: Symbol, op: LowLevel, var_store: &mut VarStore) -> Def {
+    let arg1_var = var_store.fresh();
+    let arg2_var = var_store.fresh();
+    let arg3_var = var_store.fresh();
+    let arg4_var = var_store.fresh();
+    let ret_var = var_store.fresh();
+
+    let body = RunLowLevel {
+        op,
+        args: vec![
+            (arg1_var, Var(Symbol::ARG_1)),
+            (arg2_var, Var(Symbol::ARG_2)),
+            (arg3_var, Var(Symbol::ARG_3)),
+            (arg4_var, Var(Symbol::ARG_4)),
+        ],
+        ret_var,
+    };
+
+    defn(
+        symbol,
+        vec![
+            (arg1_var, Symbol::ARG_1),
+            (arg2_var, Symbol::ARG_2),
+            (arg3_var, Symbol::ARG_3),
+            (arg4_var, Symbol::ARG_4),
+        ],
+        var_store,
+        body,
+        ret_var,
+    )
+}
+
 /// Num.maxInt : Int
 fn num_max_int(symbol: Symbol, var_store: &mut VarStore) -> Def {
     let int_var = var_store.fresh();
@@ -2122,6 +2156,11 @@ fn list_map2(symbol: Symbol, var_store: &mut VarStore) -> Def {
     lowlevel_3(symbol, LowLevel::ListMap2, var_store)
 }
 
+/// List.map3 : List a, List b, (a, b -> c) -> List c
+fn list_map3(symbol: Symbol, var_store: &mut VarStore) -> Def {
+    lowlevel_4(symbol, LowLevel::ListMap3, var_store)
+}
+
 /// Dict.hashTestOnly : k, v -> Nat
 pub fn dict_hash_test_only(symbol: Symbol, var_store: &mut VarStore) -> Def {
     lowlevel_2(symbol, LowLevel::Hash, var_store)
diff --git a/compiler/gen/src/llvm/build.rs b/compiler/gen/src/llvm/build.rs
index 98386c2270..903ec6acef 100644
--- a/compiler/gen/src/llvm/build.rs
+++ b/compiler/gen/src/llvm/build.rs
@@ -7,8 +7,8 @@ use crate::llvm::build_hash::generic_hash;
 use crate::llvm::build_list::{
     allocate_list, empty_list, empty_polymorphic_list, list_append, list_concat, list_contains,
     list_get_unsafe, list_join, list_keep_errs, list_keep_if, list_keep_oks, list_len, list_map,
-    list_map2, list_map_with_index, list_prepend, list_repeat, list_reverse, list_set, list_single,
-    list_sum, list_walk, list_walk_backwards,
+    list_map2, list_map3, list_map_with_index, list_prepend, list_repeat, list_reverse, list_set,
+    list_single, list_sum, list_walk, list_walk_backwards,
 };
 use crate::llvm::build_str::{
     str_concat, str_count_graphemes, str_ends_with, str_from_float, str_from_int, str_from_utf8,
@@ -3746,6 +3746,38 @@ fn run_low_level<'a, 'ctx, 'env>(
                 _ => unreachable!("invalid list layout"),
             }
         }
+        ListMap3 => {
+            debug_assert_eq!(args.len(), 4);
+
+            let (list1, list1_layout) = load_symbol_and_layout(scope, &args[0]);
+            let (list2, list2_layout) = load_symbol_and_layout(scope, &args[1]);
+            let (list3, list3_layout) = load_symbol_and_layout(scope, &args[2]);
+
+            let (func, func_layout) = load_symbol_and_layout(scope, &args[3]);
+
+            match (list1_layout, list2_layout, list3_layout) {
+                (
+                    Layout::Builtin(Builtin::List(_, element1_layout)),
+                    Layout::Builtin(Builtin::List(_, element2_layout)),
+                    Layout::Builtin(Builtin::List(_, element3_layout)),
+                ) => list_map3(
+                    env,
+                    layout_ids,
+                    func,
+                    func_layout,
+                    list1,
+                    list2,
+                    list3,
+                    element1_layout,
+                    element2_layout,
+                    element3_layout,
+                ),
+                (Layout::Builtin(Builtin::EmptyList), _, _)
+                | (_, Layout::Builtin(Builtin::EmptyList), _)
+                | (_, _, Layout::Builtin(Builtin::EmptyList)) => empty_list(env),
+                _ => unreachable!("invalid list layout"),
+            }
+        }
         ListMapWithIndex => {
             // List.map : List before, (before -> after) -> List after
             debug_assert_eq!(args.len(), 2);
diff --git a/compiler/gen/src/llvm/build_list.rs b/compiler/gen/src/llvm/build_list.rs
index 4124891cf0..fb3232e0b8 100644
--- a/compiler/gen/src/llvm/build_list.rs
+++ b/compiler/gen/src/llvm/build_list.rs
@@ -1305,6 +1305,114 @@ pub fn list_map2<'a, 'ctx, 'env>(
     )
 }
 
+pub fn list_map3<'a, 'ctx, 'env>(
+    env: &Env<'a, 'ctx, 'env>,
+    layout_ids: &mut LayoutIds<'a>,
+    transform: BasicValueEnum<'ctx>,
+    transform_layout: &Layout<'a>,
+    list1: BasicValueEnum<'ctx>,
+    list2: BasicValueEnum<'ctx>,
+    list3: BasicValueEnum<'ctx>,
+    element1_layout: &Layout<'a>,
+    element2_layout: &Layout<'a>,
+    element3_layout: &Layout<'a>,
+) -> BasicValueEnum<'ctx> {
+    let builder = env.builder;
+
+    let return_layout = match transform_layout {
+        Layout::FunctionPointer(_, ret) => ret,
+        Layout::Closure(_, _, ret) => ret,
+        _ => unreachable!("not a callable layout"),
+    };
+
+    let u8_ptr = env.context.i8_type().ptr_type(AddressSpace::Generic);
+
+    let list1_i128 = complex_bitcast(
+        env.builder,
+        list1,
+        env.context.i128_type().into(),
+        "to_i128",
+    );
+
+    let list2_i128 = complex_bitcast(
+        env.builder,
+        list2,
+        env.context.i128_type().into(),
+        "to_i128",
+    );
+
+    let list3_i128 = complex_bitcast(
+        env.builder,
+        list3,
+        env.context.i128_type().into(),
+        "to_i128",
+    );
+
+    let transform_ptr = builder.build_alloca(transform.get_type(), "transform_ptr");
+    env.builder.build_store(transform_ptr, transform);
+
+    let argument_layouts = [
+        element1_layout.clone(),
+        element2_layout.clone(),
+        element3_layout.clone(),
+    ];
+    let stepper_caller =
+        build_transform_caller(env, layout_ids, transform_layout, &argument_layouts)
+            .as_global_value()
+            .as_pointer_value();
+
+    let a_width = env
+        .ptr_int()
+        .const_int(element1_layout.stack_size(env.ptr_bytes) as u64, false);
+
+    let b_width = env
+        .ptr_int()
+        .const_int(element2_layout.stack_size(env.ptr_bytes) as u64, false);
+
+    let c_width = env
+        .ptr_int()
+        .const_int(element3_layout.stack_size(env.ptr_bytes) as u64, false);
+
+    let d_width = env
+        .ptr_int()
+        .const_int(return_layout.stack_size(env.ptr_bytes) as u64, false);
+
+    let alignment = return_layout.alignment_bytes(env.ptr_bytes);
+    let alignment_iv = env.ptr_int().const_int(alignment as u64, false);
+
+    let dec_a = build_dec_wrapper(env, layout_ids, element1_layout);
+    let dec_b = build_dec_wrapper(env, layout_ids, element2_layout);
+    let dec_c = build_dec_wrapper(env, layout_ids, element3_layout);
+
+    let output = call_bitcode_fn(
+        env,
+        &[
+            list1_i128,
+            list2_i128,
+            list3_i128,
+            env.builder
+                .build_bitcast(transform_ptr, u8_ptr, "to_opaque"),
+            stepper_caller.into(),
+            alignment_iv.into(),
+            a_width.into(),
+            b_width.into(),
+            c_width.into(),
+            d_width.into(),
+            dec_a.as_global_value().as_pointer_value().into(),
+            dec_b.as_global_value().as_pointer_value().into(),
+            dec_c.as_global_value().as_pointer_value().into(),
+        ],
+        bitcode::LIST_MAP3,
+    );
+
+    complex_bitcast(
+        env.builder,
+        output,
+        collection(env.context, env.ptr_bytes).into(),
+        "from_i128",
+    )
+}
+
 /// List.concat : List elem, List elem -> List elem
 pub fn list_concat<'a, 'ctx, 'env>(
     env: &Env<'a, 'ctx, 'env>,
diff --git a/compiler/module/src/low_level.rs b/compiler/module/src/low_level.rs
index c597c42076..b8a2ed31c6 100644
--- a/compiler/module/src/low_level.rs
+++ b/compiler/module/src/low_level.rs
@@ -28,6 +28,7 @@ pub enum LowLevel {
     ListJoin,
     ListMap,
     ListMap2,
+    ListMap3,
     ListMapWithIndex,
     ListKeepIf,
     ListWalk,
diff --git a/compiler/module/src/symbol.rs b/compiler/module/src/symbol.rs
index 9ecb241be0..652c8493e2 100644
--- a/compiler/module/src/symbol.rs
+++ b/compiler/module/src/symbol.rs
@@ -910,6 +910,7 @@ define_builtins! {
         22 LIST_KEEP_ERRS: "keepErrs"
         23 LIST_MAP_WITH_INDEX: "mapWithIndex"
         24 LIST_MAP2: "map2"
+        25 LIST_MAP3: "map3"
     }
     5 RESULT: "Result" => {
         0 RESULT_RESULT: "Result" imported // the Result.Result type alias
diff --git a/compiler/mono/src/borrow.rs b/compiler/mono/src/borrow.rs
index 486205fcb3..b3785ddaa9 100644
--- a/compiler/mono/src/borrow.rs
+++ b/compiler/mono/src/borrow.rs
@@ -652,6 +652,7 @@ pub fn lowlevel_borrow_signature(arena: &Bump, op: LowLevel) -> &[bool] {
         ListJoin => arena.alloc_slice_copy(&[irrelevant]),
         ListMap | ListMapWithIndex => arena.alloc_slice_copy(&[owned, irrelevant]),
         ListMap2 => arena.alloc_slice_copy(&[owned, owned, irrelevant]),
+        ListMap3 => arena.alloc_slice_copy(&[owned, owned, owned, irrelevant]),
         ListKeepIf | ListKeepOks | ListKeepErrs => arena.alloc_slice_copy(&[owned, borrowed]),
         ListContains => arena.alloc_slice_copy(&[borrowed, irrelevant]),
         ListWalk => arena.alloc_slice_copy(&[owned, irrelevant, owned]),
diff --git a/compiler/test_gen/src/gen_list.rs b/compiler/test_gen/src/gen_list.rs
index dbf974988b..28986f682c 100644
--- a/compiler/test_gen/src/gen_list.rs
+++ b/compiler/test_gen/src/gen_list.rs
@@ -568,6 +568,36 @@ fn list_map_closure() {
     );
 }
 
+#[test]
+fn list_map3_group() {
+    assert_evals_to!(
+        indoc!(
+            r#"
+            List.map3 [1,2,3] [3,2,1] [2,1,3] (\a, b, c -> Group a b c)
+            "#
+        ),
+        RocList::from_slice(&[(1, 3, 2), (2, 2, 1), (3, 1, 3)]),
+        RocList<(i64, i64, i64)>
+    );
+}
+
+#[test]
+fn list_map3_different_length() {
+    assert_evals_to!(
+        indoc!(
+            r#"
+            List.map3
+                ["a", "b", "d" ]
+                ["b"],
+                ["c"],
+                Str.concat
+            "#
+        ),
+        RocList::from_slice(&[RocStr::from_slice("abc".as_bytes()),]),
+        RocList<RocStr>
+    );
+}
+
 #[test]
 fn list_map2_pair() {
     assert_evals_to!(

From 9fc572ace95e02bdc17848467699615cdad82980 Mon Sep 17 00:00:00 2001
From: rvcas <x@rvcas.dev>
Date: Mon, 8 Mar 2021 21:14:15 -0500
Subject: [PATCH 11/74] fix(List): map3 ref count use dec_c on third list

---
 compiler/builtins/bitcode/src/list.zig | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/compiler/builtins/bitcode/src/list.zig b/compiler/builtins/bitcode/src/list.zig
index 95137d25bb..bd765e1eca 100644
--- a/compiler/builtins/bitcode/src/list.zig
+++ b/compiler/builtins/bitcode/src/list.zig
@@ -253,7 +253,7 @@ pub fn listMap3(list1: RocList, list2: RocList, list3: RocList, transform: Opaqu
                 if (list3.len() > output_length) {
                     while (i < list3.len()) : (i += 1) {
                         const element_c = source_c + i * c_width;
-                        dec_b(element_c);
+                        dec_c(element_c);
                     }
                 }
 

From bebd96674b5364849e1beaa8cac18024a14cf8d2 Mon Sep 17 00:00:00 2001
From: rvcas <x@rvcas.dev>
Date: Mon, 8 Mar 2021 21:18:22 -0500
Subject: [PATCH 12/74] fix(List): export map3 from main.zig

---
 compiler/builtins/bitcode/src/main.zig | 1 +
 1 file changed, 1 insertion(+)

diff --git a/compiler/builtins/bitcode/src/main.zig b/compiler/builtins/bitcode/src/main.zig
index e0f501654b..4cd57a84a5 100644
--- a/compiler/builtins/bitcode/src/main.zig
+++ b/compiler/builtins/bitcode/src/main.zig
@@ -8,6 +8,7 @@ const list = @import("list.zig");
 comptime {
     exportListFn(list.listMap, "map");
     exportListFn(list.listMap2, "map2");
+    exportListFn(list.listMap3, "map3");
     exportListFn(list.listMapWithIndex, "map_with_index");
     exportListFn(list.listKeepIf, "keep_if");
     exportListFn(list.listWalk, "walk");

From dfc36bd4a82f4ec064a9395fd51b63947a6bd48e Mon Sep 17 00:00:00 2001
From: rvcas <x@rvcas.dev>
Date: Mon, 8 Mar 2021 21:42:11 -0500
Subject: [PATCH 13/74] fix(List): parse error in tests

---
 compiler/test_gen/src/gen_list.rs | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/compiler/test_gen/src/gen_list.rs b/compiler/test_gen/src/gen_list.rs
index 28986f682c..34244d06fb 100644
--- a/compiler/test_gen/src/gen_list.rs
+++ b/compiler/test_gen/src/gen_list.rs
@@ -588,8 +588,8 @@ fn list_map3_different_length() {
             r#"
             List.map3
                 ["a", "b", "d" ]
-                ["b"],
-                ["c"],
+                ["b"]
+                ["c"]
                 Str.concat
             "#
         ),

From afe9c27c19facc352ed53394b3d80c25dcc7f33f Mon Sep 17 00:00:00 2001
From: rvcas <x@rvcas.dev>
Date: Mon, 8 Mar 2021 21:46:06 -0500
Subject: [PATCH 14/74] fix(List): in test, Str.concat only takes 2 args, need
 to pass lambda

---
 compiler/test_gen/src/gen_list.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/compiler/test_gen/src/gen_list.rs b/compiler/test_gen/src/gen_list.rs
index 34244d06fb..83d93eebf2 100644
--- a/compiler/test_gen/src/gen_list.rs
+++ b/compiler/test_gen/src/gen_list.rs
@@ -590,7 +590,7 @@ fn list_map3_different_length() {
                 ["a", "b", "d" ]
                 ["b"]
                 ["c"]
-                Str.concat
+                (\a, b, c -> Str.concat a (Str.concat b c))
             "#
         ),
         RocList::from_slice(&[RocStr::from_slice("abc".as_bytes()),]),

From 73365fe5fa0ab0a020a2cd1395ebd5087bc9c02a Mon Sep 17 00:00:00 2001
From: Anton-4 <17049058+Anton-4@users.noreply.github.com>
Date: Tue, 9 Mar 2021 11:15:48 +0100
Subject: [PATCH 15/74] added g++ to dependencies for spirv_cross

---
 Earthfile | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Earthfile b/Earthfile
index d4f41a014c..e4df77170f 100644
--- a/Earthfile
+++ b/Earthfile
@@ -8,7 +8,7 @@ install-other-libs:
     FROM +prep-debian
     RUN apt -y install wget git
     RUN apt -y install libxcb-shape0-dev libxcb-xfixes0-dev # for editor clipboard
-    RUN apt -y install libc++-dev libc++abi-dev libunwind-dev pkg-config libx11-dev zlib1g-dev
+    RUN apt -y install libc++-dev libc++abi-dev g++ libunwind-dev pkg-config libx11-dev zlib1g-dev
 
 install-zig-llvm-valgrind-clippy-rustfmt:
     FROM +install-other-libs

From 71ab77b804192f765c3a66d54d430f7a78779d2f Mon Sep 17 00:00:00 2001
From: Folkert <folkert@folkertdev.nl>
Date: Tue, 9 Mar 2021 14:39:25 +0100
Subject: [PATCH 16/74] start of imports

---
 compiler/parse/src/module.rs               | 227 +++++++++++++++++----
 compiler/parse/src/parser.rs               |  47 +++++
 compiler/reporting/src/error/parse.rs      | 160 ++++++++++++++-
 compiler/reporting/tests/test_reporting.rs |  32 ++-
 4 files changed, 418 insertions(+), 48 deletions(-)

diff --git a/compiler/parse/src/module.rs b/compiler/parse/src/module.rs
index fdc9aede9d..ecac928a90 100644
--- a/compiler/parse/src/module.rs
+++ b/compiler/parse/src/module.rs
@@ -9,8 +9,8 @@ use crate::ident::{lowercase_ident, unqualified_ident, uppercase_ident};
 use crate::parser::Progress::{self, *};
 use crate::parser::{
     self, ascii_char, ascii_string, backtrackable, end_of_file, loc, optional, peek_utf8_char,
-    peek_utf8_char_at, specialize, unexpected, unexpected_eof, word1, EHeader, EProvides,
-    ParseResult, Parser, State, SyntaxError,
+    peek_utf8_char_at, specialize, unexpected, unexpected_eof, word1, Col, EExposes, EHeader,
+    EImports, EProvides, ParseResult, Parser, Row, State, SyntaxError,
 };
 use crate::string_literal;
 use crate::type_annotation;
@@ -342,22 +342,23 @@ fn provides_to_help<'a>() -> impl Parser<'a, ProvidesTo<'a>, EProvides> {
         and!(
             provides_without_to_help(),
             and!(
-                space0_e(min_indent, EProvides::Space, EProvides::IndentTo),
-                skip_first!(
-                    crate::parser::keyword_e("to", EProvides::To),
-                    and!(
-                        space0_e(min_indent, EProvides::Space, EProvides::IndentPackage),
-                        loc!(specialize(
-                            |_, r, c| EProvides::Package(r, c),
-                            provides_to_package()
-                        ))
-                    )
-                )
+                spaces_around_keyword(
+                    min_indent,
+                    "to",
+                    EProvides::To,
+                    EProvides::Space,
+                    EProvides::IndentTo,
+                    EProvides::IndentListStart
+                ),
+                loc!(specialize(
+                    |_, r, c| EProvides::Package(r, c),
+                    provides_to_package()
+                ))
             )
         ),
         |(
             ((before_provides_keyword, after_provides_keyword), entries),
-            (before_to_keyword, (after_to_keyword, to)),
+            ((before_to_keyword, after_to_keyword), to),
         )| {
             ProvidesTo {
                 entries,
@@ -397,12 +398,13 @@ fn provides_without_to_help<'a>() -> impl Parser<
 > {
     let min_indent = 1;
     and!(
-        and!(
-            skip_second!(
-                space0_e(min_indent, EProvides::Space, EProvides::IndentProvides),
-                crate::parser::keyword_e("provides", EProvides::Provides)
-            ),
-            space0_e(min_indent, EProvides::Space, EProvides::IndentListStart)
+        spaces_around_keyword(
+            min_indent,
+            "provides",
+            EProvides::Provides,
+            EProvides::Space,
+            EProvides::IndentProvides,
+            EProvides::IndentListStart
         ),
         collection_e!(
             word1(b'[', EProvides::ListStart),
@@ -460,14 +462,40 @@ fn exposes_values<'a>() -> impl Parser<
     ),
     SyntaxError<'a>,
 > {
+    specialize(
+        |e, r, c| SyntaxError::Header(EHeader::Exposes(e, r, c)),
+        exposes_values_help(),
+    )
+}
+
+#[inline(always)]
+fn exposes_values_help<'a>() -> impl Parser<
+    'a,
+    (
+        (&'a [CommentOrNewline<'a>], &'a [CommentOrNewline<'a>]),
+        Vec<'a, Located<ExposesEntry<'a, &'a str>>>,
+    ),
+    EExposes,
+> {
+    let min_indent = 1;
+
     and!(
-        and!(skip_second!(space1(1), ascii_string("exposes")), space1(1)),
-        collection!(
-            ascii_char(b'['),
-            loc!(map!(unqualified_ident(), ExposesEntry::Exposed)),
-            ascii_char(b','),
-            ascii_char(b']'),
-            1
+        spaces_around_keyword(
+            min_indent,
+            "exposes",
+            EExposes::Exposes,
+            EExposes::Space,
+            EExposes::IndentExposes,
+            EExposes::IndentListStart
+        ),
+        collection_e!(
+            word1(b'[', EExposes::ListStart),
+            exposes_entry(EExposes::Identifier),
+            word1(b',', EExposes::ListEnd),
+            word1(b']', EExposes::ListEnd),
+            min_indent,
+            EExposes::Space,
+            EExposes::IndentListEnd
         )
     )
 }
@@ -481,18 +509,78 @@ fn exposes_modules<'a>() -> impl Parser<
     ),
     SyntaxError<'a>,
 > {
+    specialize(
+        |e, r, c| SyntaxError::Header(EHeader::Exposes(e, r, c)),
+        exposes_modules_help(),
+    )
+}
+
+fn spaces_around_keyword<'a, E>(
+    min_indent: u16,
+    keyword: &'static str,
+    expectation: fn(Row, Col) -> E,
+    space_problem: fn(crate::parser::BadInputError, Row, Col) -> E,
+    indent_problem1: fn(Row, Col) -> E,
+    indent_problem2: fn(Row, Col) -> E,
+) -> impl Parser<'a, (&'a [CommentOrNewline<'a>], &'a [CommentOrNewline<'a>]), E>
+where
+    E: 'a,
+{
     and!(
-        and!(skip_second!(space1(1), ascii_string("exposes")), space1(1)),
-        collection!(
-            ascii_char(b'['),
-            loc!(map!(module_name(), ExposesEntry::Exposed)),
-            ascii_char(b','),
-            ascii_char(b']'),
-            1
+        skip_second!(
+            space0_e(min_indent, space_problem, indent_problem1),
+            crate::parser::keyword_e(keyword, expectation)
+        ),
+        space0_e(min_indent, space_problem, indent_problem2)
+    )
+}
+
+#[inline(always)]
+fn exposes_modules_help<'a>() -> impl Parser<
+    'a,
+    (
+        (&'a [CommentOrNewline<'a>], &'a [CommentOrNewline<'a>]),
+        Vec<'a, Located<ExposesEntry<'a, ModuleName<'a>>>>,
+    ),
+    EExposes,
+> {
+    let min_indent = 1;
+
+    and!(
+        spaces_around_keyword(
+            min_indent,
+            "exposes",
+            EExposes::Exposes,
+            EExposes::Space,
+            EExposes::IndentExposes,
+            EExposes::IndentListStart
+        ),
+        collection_e!(
+            word1(b'[', EExposes::ListStart),
+            exposes_module(EExposes::Identifier),
+            word1(b',', EExposes::ListEnd),
+            word1(b']', EExposes::ListEnd),
+            min_indent,
+            EExposes::Space,
+            EExposes::IndentListEnd
         )
     )
 }
 
+fn exposes_module<'a, F, E>(
+    to_expectation: F,
+) -> impl Parser<'a, Located<ExposesEntry<'a, ModuleName<'a>>>, E>
+where
+    F: Fn(crate::parser::Row, crate::parser::Col) -> E,
+    F: Copy,
+    E: 'a,
+{
+    loc!(map!(
+        specialize(|_, r, c| to_expectation(r, c), module_name()),
+        ExposesEntry::Exposed
+    ))
+}
+
 #[derive(Debug)]
 struct Packages<'a> {
     entries: Vec<'a, Located<PackageEntry<'a>>>,
@@ -551,6 +639,30 @@ fn imports<'a>() -> impl Parser<
     )
 }
 
+#[inline(always)]
+fn imports_help<'a>() -> impl Parser<
+    'a,
+    (
+        (&'a [CommentOrNewline<'a>], &'a [CommentOrNewline<'a>]),
+        Vec<'a, Located<ImportsEntry<'a>>>,
+    ),
+    SyntaxError<'a>,
+> {
+    and!(
+        and!(
+            skip_second!(backtrackable(space1(1)), ascii_string("imports")),
+            space1(1)
+        ),
+        collection!(
+            ascii_char(b'['),
+            loc!(imports_entry()),
+            ascii_char(b','),
+            ascii_char(b']'),
+            1
+        )
+    )
+}
+
 #[inline(always)]
 fn effects<'a>() -> impl Parser<'a, Effects<'a>, SyntaxError<'a>> {
     move |arena, state| {
@@ -621,23 +733,50 @@ fn typed_ident<'a>() -> impl Parser<'a, TypedIdent<'a>, SyntaxError<'a>> {
 #[inline(always)]
 #[allow(clippy::type_complexity)]
 fn imports_entry<'a>() -> impl Parser<'a, ImportsEntry<'a>, SyntaxError<'a>> {
+    specialize(
+        |e, r, c| SyntaxError::Header(EHeader::Imports(e, r, c)),
+        imports_entry_help(),
+    )
+}
+
+fn shortname<'a>() -> impl Parser<'a, &'a str, EImports> {
+    specialize(|_, r, c| EImports::Shortname(r, c), lowercase_ident())
+}
+
+fn module_name_help<'a, F, E>(to_expectation: F) -> impl Parser<'a, ModuleName<'a>, E>
+where
+    F: Fn(crate::parser::Row, crate::parser::Col) -> E,
+    E: 'a,
+    F: 'a,
+{
+    specialize(move |_, r, c| to_expectation(r, c), module_name())
+}
+
+fn imports_entry_help<'a>() -> impl Parser<'a, ImportsEntry<'a>, EImports> {
+    let min_indent = 1;
+
     map_with_arena!(
         and!(
             and!(
                 // e.g. `base.`
-                optional(skip_second!(lowercase_ident(), ascii_char(b'.'))),
+                maybe!(skip_second!(
+                    shortname(),
+                    word1(b'.', EImports::ShorthandDot)
+                )),
                 // e.g. `Task`
-                module_name()
+                module_name_help(EImports::ModuleName)
             ),
             // e.g. `.{ Task, after}`
-            optional(skip_first!(
-                ascii_char(b'.'),
-                collection!(
-                    ascii_char(b'{'),
-                    loc!(map!(unqualified_ident(), ExposesEntry::Exposed)),
-                    ascii_char(b','),
-                    ascii_char(b'}'),
-                    1
+            maybe!(skip_first!(
+                word1(b'.', EImports::ExposingDot),
+                collection_e!(
+                    word1(b'{', EImports::SetStart),
+                    exposes_entry(EImports::Identifier),
+                    word1(b',', EImports::SetEnd),
+                    word1(b'}', EImports::SetEnd),
+                    min_indent,
+                    EImports::Space,
+                    EImports::IndentSetEnd
                 )
             ))
         ),
diff --git a/compiler/parse/src/parser.rs b/compiler/parse/src/parser.rs
index 1ab906ea70..1d831bbf6b 100644
--- a/compiler/parse/src/parser.rs
+++ b/compiler/parse/src/parser.rs
@@ -341,6 +341,8 @@ pub enum SyntaxError<'a> {
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
 pub enum EHeader {
     Provides(EProvides, Row, Col),
+    Exposes(EExposes, Row, Col),
+    Imports(EImports, Row, Col),
 }
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
@@ -359,6 +361,38 @@ pub enum EProvides {
     Space(BadInputError, Row, Col),
 }
 
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub enum EExposes {
+    Exposes(Row, Col),
+    IndentExposes(Row, Col),
+    IndentListStart(Row, Col),
+    IndentListEnd(Row, Col),
+    ListStart(Row, Col),
+    ListEnd(Row, Col),
+    Identifier(Row, Col),
+    Space(BadInputError, Row, Col),
+}
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub enum EImports {
+    Imports(Row, Col),
+    IndentImports(Row, Col),
+    IndentListStart(Row, Col),
+    IndentListEnd(Row, Col),
+    ListStart(Row, Col),
+    ListEnd(Row, Col),
+    Identifier(Row, Col),
+    ExposingDot(Row, Col),
+    ShorthandDot(Row, Col),
+    Shortname(Row, Col),
+    ModuleName(Row, Col),
+    Space(BadInputError, Row, Col),
+    IndentSetStart(Row, Col),
+    IndentSetEnd(Row, Col),
+    SetStart(Row, Col),
+    SetEnd(Row, Col),
+}
+
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
 pub enum BadInputError {
     HasTab,
@@ -1777,6 +1811,19 @@ macro_rules! one_of {
     };
 }
 
+#[macro_export]
+macro_rules! maybe {
+    ($p1:expr) => {
+        move |arena: &'a bumpalo::Bump, state: $crate::parser::State<'a>| match $p1
+            .parse(arena, state)
+        {
+            Ok((progress, value, state)) => Ok((progress, Some(value), state)),
+            Err((MadeProgress, fail, state)) => Err((MadeProgress, fail, state)),
+            Err((NoProgress, _, state)) => Ok((NoProgress, None, state)),
+        }
+    };
+}
+
 #[macro_export]
 macro_rules! one_of_with_error {
     ($toerror:expr; $p1:expr) => {
diff --git a/compiler/reporting/src/error/parse.rs b/compiler/reporting/src/error/parse.rs
index 8e2dca66a3..93eebfcdf8 100644
--- a/compiler/reporting/src/error/parse.rs
+++ b/compiler/reporting/src/error/parse.rs
@@ -2482,7 +2482,15 @@ fn to_header_report<'a>(
     match *parse_problem {
         EHeader::Provides(provides, row, col) => {
             to_provides_report(alloc, filename, &provides, row, col)
-        } // _ => todo!("unhandled parse error {:?}", parse_problem),
+        }
+
+        EHeader::Exposes(exposes, row, col) => {
+            to_exposes_report(alloc, filename, &exposes, row, col)
+        }
+
+        EHeader::Imports(imports, row, col) => {
+            to_imports_report(alloc, filename, &imports, row, col)
+        }
     }
 }
 
@@ -2520,12 +2528,162 @@ fn to_provides_report<'a>(
             }
         }
 
+        EProvides::Provides(row, col) => {
+            let surroundings = Region::from_rows_cols(start_row, start_col, row, col);
+            let region = Region::from_row_col(row, col);
+
+            let doc = alloc.stack(vec![
+                alloc.reflow(r"I am in the middle of a header, but I got stuck here:"),
+                alloc.region_with_subregion(surroundings, region),
+                alloc.concat(vec![
+                    alloc.reflow("I am expecting the "),
+                    alloc.keyword("provides"),
+                    alloc.reflow(" keyword next, like "),
+                ]),
+                alloc
+                    .parser_suggestion("provides [ Animal, default, tame ]")
+                    .indent(4),
+            ]);
+
+            Report {
+                filename,
+                doc,
+                title: "WEIRD PROVIDES".to_string(),
+            }
+        }
+
         EProvides::Space(error, row, col) => to_space_report(alloc, filename, &error, row, col),
 
         _ => todo!("unhandled parse error {:?}", parse_problem),
     }
 }
 
+fn to_exposes_report<'a>(
+    alloc: &'a RocDocAllocator<'a>,
+    filename: PathBuf,
+    parse_problem: &roc_parse::parser::EExposes,
+    start_row: Row,
+    start_col: Col,
+) -> Report<'a> {
+    use roc_parse::parser::EExposes;
+
+    match *parse_problem {
+        EExposes::Identifier(row, col) => {
+            let surroundings = Region::from_rows_cols(start_row, start_col, row, col);
+            let region = Region::from_row_col(row, col);
+
+            let doc = alloc.stack(vec![
+                alloc
+                    .reflow(r"I am in the middle of parsing a exposes list, but I got stuck here:"),
+                alloc.region_with_subregion(surroundings, region),
+                alloc.concat(vec![alloc.reflow(
+                    "I was expecting a type name, value name or function name next, like ",
+                )]),
+                alloc
+                    .parser_suggestion("exposes [ Animal, default, tame ]")
+                    .indent(4),
+            ]);
+
+            Report {
+                filename,
+                doc,
+                title: "WEIRD EXPOSES".to_string(),
+            }
+        }
+
+        EExposes::Exposes(row, col) => {
+            let surroundings = Region::from_rows_cols(start_row, start_col, row, col);
+            let region = Region::from_row_col(row, col);
+
+            let doc = alloc.stack(vec![
+                alloc.reflow(r"I am in the middle of a header, but I got stuck here:"),
+                alloc.region_with_subregion(surroundings, region),
+                alloc.concat(vec![
+                    alloc.reflow("I am expecting the "),
+                    alloc.keyword("exposes"),
+                    alloc.reflow(" keyword next, like "),
+                ]),
+                alloc
+                    .parser_suggestion("exposes [ Animal, default, tame ]")
+                    .indent(4),
+            ]);
+
+            Report {
+                filename,
+                doc,
+                title: "WEIRD EXPOSES".to_string(),
+            }
+        }
+
+        EExposes::Space(error, row, col) => to_space_report(alloc, filename, &error, row, col),
+
+        _ => todo!("unhandled parse error {:?}", parse_problem),
+    }
+}
+
+fn to_imports_report<'a>(
+    alloc: &'a RocDocAllocator<'a>,
+    filename: PathBuf,
+    parse_problem: &roc_parse::parser::EImports,
+    start_row: Row,
+    start_col: Col,
+) -> Report<'a> {
+    use roc_parse::parser::EImports;
+
+    match *parse_problem {
+        EImports::Identifier(row, col) => {
+            let surroundings = Region::from_rows_cols(start_row, start_col, row, col);
+            let region = Region::from_row_col(row, col);
+
+            let doc = alloc.stack(vec![
+                alloc
+                    .reflow(r"I am in the middle of parsing a imports list, but I got stuck here:"),
+                alloc.region_with_subregion(surroundings, region),
+                alloc.concat(vec![alloc.reflow(
+                    "I was expecting a type name, value name or function name next, like ",
+                )]),
+                alloc
+                    .parser_suggestion("imports [ Animal, default, tame ]")
+                    .indent(4),
+            ]);
+
+            Report {
+                filename,
+                doc,
+                title: "WEIRD EXPOSES".to_string(),
+            }
+        }
+
+        EImports::Imports(row, col) => {
+            let surroundings = Region::from_rows_cols(start_row, start_col, row, col);
+            let region = Region::from_row_col(row, col);
+
+            let doc = alloc.stack(vec![
+                alloc.reflow(r"I am in the middle of a header, but I got stuck here:"),
+                alloc.region_with_subregion(surroundings, region),
+                alloc.concat(vec![
+                    alloc.reflow("I am expecting the "),
+                    alloc.keyword("imports"),
+                    alloc.reflow(" keyword next, like "),
+                ]),
+                alloc
+                    .parser_suggestion("imports [ Animal, default, tame ]")
+                    .indent(4),
+            ]);
+
+            Report {
+                filename,
+                doc,
+                title: "WEIRD IMPORTS".to_string(),
+            }
+        }
+
+        EImports::Space(error, row, col) => to_space_report(alloc, filename, &error, row, col),
+
+        _ => todo!("unhandled parse error {:?}", parse_problem),
+    }
+}
+
 fn to_space_report<'a>(
     alloc: &'a RocDocAllocator<'a>,
     filename: PathBuf,
diff --git a/compiler/reporting/tests/test_reporting.rs b/compiler/reporting/tests/test_reporting.rs
index 2980c65927..bef4e30107 100644
--- a/compiler/reporting/tests/test_reporting.rs
+++ b/compiler/reporting/tests/test_reporting.rs
@@ -5758,9 +5758,7 @@ mod test_reporting {
     }
 
     #[test]
-    fn provides_to() {
-        // this is still bad, but changing the order and progress of other parsers should improve it
-        // down the line
+    fn provides_to_identifier() {
         report_header_problem_as(
             indoc!(
                 r#"
@@ -5787,4 +5785,32 @@ mod test_reporting {
             ),
         )
     }
+
+    #[test]
+    fn exposes_identifier() {
+        report_header_problem_as(
+            indoc!(
+                r#"
+                interface Foobar 
+                    exposes [ main, @Foo ]
+                    imports [base.Task, Base64 ]
+                "#
+            ),
+            indoc!(
+                r#"
+                ── WEIRD EXPOSES ───────────────────────────────────────────────────────────────
+                
+                I am in the middle of parsing a exposes list, but I got stuck here:
+                
+                1│  interface Foobar 
+                2│      exposes [ main, @Foo ]
+                                        ^
+                
+                I was expecting a type name, value name or function name next, like 
+                
+                    exposes [ Animal, default, tame ]
+            "#
+            ),
+        )
+    }
 }

From f25e88397ae383ad2ae68a78943f45fcbde6c561 Mon Sep 17 00:00:00 2001
From: Folkert <folkert@folkertdev.nl>
Date: Tue, 9 Mar 2021 15:23:45 +0100
Subject: [PATCH 17/74] finish import

---
 compiler/parse/src/module.rs | 53 +++++++++++++++---------------------
 1 file changed, 22 insertions(+), 31 deletions(-)

diff --git a/compiler/parse/src/module.rs b/compiler/parse/src/module.rs
index ecac928a90..eaa9b495e6 100644
--- a/compiler/parse/src/module.rs
+++ b/compiler/parse/src/module.rs
@@ -624,18 +624,9 @@ fn imports<'a>() -> impl Parser<
     ),
     SyntaxError<'a>,
 > {
-    and!(
-        and!(
-            skip_second!(backtrackable(space1(1)), ascii_string("imports")),
-            space1(1)
-        ),
-        collection!(
-            ascii_char(b'['),
-            loc!(imports_entry()),
-            ascii_char(b','),
-            ascii_char(b']'),
-            1
-        )
+    specialize(
+        |e, r, c| SyntaxError::Header(EHeader::Imports(e, r, c)),
+        imports_help(),
     )
 }
 
@@ -646,19 +637,27 @@ fn imports_help<'a>() -> impl Parser<
         (&'a [CommentOrNewline<'a>], &'a [CommentOrNewline<'a>]),
         Vec<'a, Located<ImportsEntry<'a>>>,
     ),
-    SyntaxError<'a>,
+    EImports,
 > {
+    let min_indent = 1;
+
     and!(
-        and!(
-            skip_second!(backtrackable(space1(1)), ascii_string("imports")),
-            space1(1)
+        spaces_around_keyword(
+            min_indent,
+            "imports",
+            EImports::Imports,
+            EImports::Space,
+            EImports::IndentImports,
+            EImports::IndentListStart
         ),
-        collection!(
-            ascii_char(b'['),
+        collection_e!(
+            word1(b'[', EImports::ListStart),
             loc!(imports_entry()),
-            ascii_char(b','),
-            ascii_char(b']'),
-            1
+            word1(b',', EImports::ListEnd),
+            word1(b']', EImports::ListEnd),
+            min_indent,
+            EImports::Space,
+            EImports::IndentListEnd
         )
     )
 }
@@ -730,15 +729,6 @@ fn typed_ident<'a>() -> impl Parser<'a, TypedIdent<'a>, SyntaxError<'a>> {
     }
 }
 
-#[inline(always)]
-#[allow(clippy::type_complexity)]
-fn imports_entry<'a>() -> impl Parser<'a, ImportsEntry<'a>, SyntaxError<'a>> {
-    specialize(
-        |e, r, c| SyntaxError::Header(EHeader::Imports(e, r, c)),
-        imports_entry_help(),
-    )
-}
-
 fn shortname<'a>() -> impl Parser<'a, &'a str, EImports> {
     specialize(|_, r, c| EImports::Shortname(r, c), lowercase_ident())
 }
@@ -752,7 +742,8 @@ where
     specialize(move |_, r, c| to_expectation(r, c), module_name())
 }
 
-fn imports_entry_help<'a>() -> impl Parser<'a, ImportsEntry<'a>, EImports> {
+#[inline(always)]
+fn imports_entry<'a>() -> impl Parser<'a, ImportsEntry<'a>, EImports> {
     let min_indent = 1;
 
     map_with_arena!(

From 322c645714d7b1dc22c47fe940911c662b19c2e5 Mon Sep 17 00:00:00 2001
From: Folkert <folkert@folkertdev.nl>
Date: Tue, 9 Mar 2021 16:48:42 +0100
Subject: [PATCH 18/74] refactor

---
 compiler/parse/src/module.rs          | 379 ++++++++++++++------------
 compiler/parse/src/parser.rs          |  30 +-
 compiler/parse/tests/test_parse.rs    | 123 ++++-----
 compiler/reporting/src/error/parse.rs |  54 +++-
 4 files changed, 334 insertions(+), 252 deletions(-)

diff --git a/compiler/parse/src/module.rs b/compiler/parse/src/module.rs
index eaa9b495e6..6a51c34c67 100644
--- a/compiler/parse/src/module.rs
+++ b/compiler/parse/src/module.rs
@@ -1,5 +1,5 @@
 use crate::ast::{Attempting, CommentOrNewline, Def, Module};
-use crate::blankspace::{space0, space0_around, space0_before, space0_e, space1};
+use crate::blankspace::{space0, space0_around, space0_before, space0_before_e, space0_e, space1};
 use crate::expr::def;
 use crate::header::{
     package_entry, package_or_path, AppHeader, Effects, ExposesEntry, ImportsEntry,
@@ -10,7 +10,7 @@ use crate::parser::Progress::{self, *};
 use crate::parser::{
     self, ascii_char, ascii_string, backtrackable, end_of_file, loc, optional, peek_utf8_char,
     peek_utf8_char_at, specialize, unexpected, unexpected_eof, word1, Col, EExposes, EHeader,
-    EImports, EProvides, ParseResult, Parser, Row, State, SyntaxError,
+    EImports, EProvides, ERequires, ETypedIdent, ParseResult, Parser, Row, State, SyntaxError,
 };
 use crate::string_literal;
 use crate::type_annotation;
@@ -19,55 +19,46 @@ use bumpalo::Bump;
 use roc_region::all::Located;
 
 pub fn header<'a>() -> impl Parser<'a, Module<'a>, SyntaxError<'a>> {
-    one_of!(interface_module(), app_module(), platform_module())
-}
-
-#[inline(always)]
-fn app_module<'a>() -> impl Parser<'a, Module<'a>, SyntaxError<'a>> {
-    map!(app_header(), |header| { Module::App { header } })
-}
-
-#[inline(always)]
-fn platform_module<'a>() -> impl Parser<'a, Module<'a>, SyntaxError<'a>> {
-    map!(platform_header(), |header| { Module::Platform { header } })
-}
-
-#[inline(always)]
-fn interface_module<'a>() -> impl Parser<'a, Module<'a>, SyntaxError<'a>> {
-    map!(interface_header(), |header| {
-        Module::Interface { header }
-    })
-}
-
-#[inline(always)]
-pub fn interface_header<'a>() -> impl Parser<'a, InterfaceHeader<'a>, SyntaxError<'a>> {
-    parser::map(
-        and!(
-            skip_first!(
-                ascii_string("interface"),
-                and!(space1(1), loc!(module_name()))
-            ),
-            and!(exposes_values(), imports())
+    one_of![
+        map!(
+            skip_first!(debug!(ascii_string("app")), app_header()),
+            |header| { Module::App { header } }
         ),
-        |(
-            (after_interface_keyword, name),
-            (
-                ((before_exposes, after_exposes), exposes),
-                ((before_imports, after_imports), imports),
-            ),
-        )| {
-            InterfaceHeader {
-                name,
-                exposes,
-                imports,
-                after_interface_keyword,
-                before_exposes,
-                after_exposes,
-                before_imports,
-                after_imports,
-            }
-        },
-    )
+        map!(
+            skip_first!(ascii_string("platform"), platform_header()),
+            |header| { Module::Platform { header } }
+        ),
+        map!(
+            skip_first!(debug!(ascii_string("interface")), interface_header()),
+            |header| { Module::Interface { header } }
+        )
+    ]
+}
+
+#[inline(always)]
+fn interface_header<'a>() -> impl Parser<'a, InterfaceHeader<'a>, SyntaxError<'a>> {
+    |arena, state| {
+        let (_, after_interface_keyword, state) = space1(1).parse(arena, state)?;
+        let (_, name, state) = loc!(module_name()).parse(arena, state)?;
+
+        let (_, ((before_exposes, after_exposes), exposes), state) =
+            exposes_values().parse(arena, state)?;
+        let (_, ((before_imports, after_imports), imports), state) =
+            imports().parse(arena, state)?;
+
+        let header = InterfaceHeader {
+            name,
+            exposes,
+            imports,
+            after_interface_keyword,
+            before_exposes,
+            after_exposes,
+            before_imports,
+            after_imports,
+        };
+
+        Ok((MadeProgress, header, state))
+    }
 }
 
 #[inline(always)]
@@ -87,10 +78,12 @@ pub fn package_name<'a>() -> impl Parser<'a, PackageName<'a>, SyntaxError<'a>> {
     )
 }
 
-pub fn parse_package_part<'a>(
+fn parse_package_part<'a>(
     arena: &'a Bump,
     mut state: State<'a>,
 ) -> ParseResult<'a, &'a str, SyntaxError<'a>> {
+    use encode_unicode::CharExt;
+
     let mut part_buf = String::new_in(arena); // The current "part" (parts are dot-separated.)
 
     while !state.bytes.is_empty() {
@@ -184,123 +177,109 @@ pub fn module_name<'a>() -> impl Parser<'a, ModuleName<'a>, SyntaxError<'a>> {
 }
 
 #[inline(always)]
-pub fn app_header<'a>() -> impl Parser<'a, AppHeader<'a>, SyntaxError<'a>> {
-    map_with_arena!(
-        and!(
-            skip_first!(
-                ascii_string("app"),
-                and!(
-                    space1(1),
-                    loc!(crate::parser::specialize(
-                        |e, r, c| SyntaxError::Expr(crate::parser::EExpr::Str(e, r, c)),
-                        string_literal::parse()
-                    ))
+fn app_header<'a>() -> impl Parser<'a, AppHeader<'a>, SyntaxError<'a>> {
+    |arena, state| {
+        let (_, after_app_keyword, state) = space1(1).parse(arena, state)?;
+        let (_, name, state) = loc!(crate::parser::specialize(
+            |e, r, c| SyntaxError::Expr(crate::parser::EExpr::Str(e, r, c)),
+            string_literal::parse()
+        ))
+        .parse(arena, state)?;
+
+        let (_, opt_pkgs, state) = maybe!(packages()).parse(arena, state)?;
+        let (_, opt_imports, state) = maybe!(imports()).parse(arena, state)?;
+        let (_, provides, state) = provides_to().parse(arena, state)?;
+
+        let (before_packages, after_packages, package_entries) = match opt_pkgs {
+            Some(pkgs) => {
+                let pkgs: Packages<'a> = pkgs; // rustc must be told the type here
+
+                (
+                    pkgs.before_packages_keyword,
+                    pkgs.after_packages_keyword,
+                    pkgs.entries,
                 )
-            ),
-            and!(
-                optional(packages()),
-                and!(optional(imports()), provides_to())
-            )
-        ),
-        |arena, ((after_app_keyword, name), (opt_pkgs, (opt_imports, provides)))| {
-            let (before_packages, after_packages, package_entries) = match opt_pkgs {
-                Some(pkgs) => {
-                    let pkgs: Packages<'a> = pkgs; // rustc must be told the type here
-
-                    (
-                        pkgs.before_packages_keyword,
-                        pkgs.after_packages_keyword,
-                        pkgs.entries,
-                    )
-                }
-                None => (&[] as _, &[] as _, Vec::new_in(arena)),
-            };
-
-            // rustc must be told the type here
-            #[allow(clippy::type_complexity)]
-            let opt_imports: Option<(
-                (&'a [CommentOrNewline<'a>], &'a [CommentOrNewline<'a>]),
-                Vec<'a, Located<ImportsEntry<'a>>>,
-            )> = opt_imports;
-
-            let ((before_imports, after_imports), imports) =
-                opt_imports.unwrap_or_else(|| ((&[] as _, &[] as _), Vec::new_in(arena)));
-            let provides: ProvidesTo<'a> = provides; // rustc must be told the type here
-
-            AppHeader {
-                name,
-                packages: package_entries,
-                imports,
-                provides: provides.entries,
-                to: provides.to,
-                after_app_keyword,
-                before_packages,
-                after_packages,
-                before_imports,
-                after_imports,
-                before_provides: provides.before_provides_keyword,
-                after_provides: provides.after_provides_keyword,
-                before_to: provides.before_to_keyword,
-                after_to: provides.after_to_keyword,
             }
-        }
-    )
+            None => (&[] as _, &[] as _, Vec::new_in(arena)),
+        };
+
+        // rustc must be told the type here
+        #[allow(clippy::type_complexity)]
+        let opt_imports: Option<(
+            (&'a [CommentOrNewline<'a>], &'a [CommentOrNewline<'a>]),
+            Vec<'a, Located<ImportsEntry<'a>>>,
+        )> = opt_imports;
+
+        let ((before_imports, after_imports), imports) =
+            opt_imports.unwrap_or_else(|| ((&[] as _, &[] as _), Vec::new_in(arena)));
+        let provides: ProvidesTo<'a> = provides; // rustc must be told the type here
+
+        let header = AppHeader {
+            name,
+            packages: package_entries,
+            imports,
+            provides: provides.entries,
+            to: provides.to,
+            after_app_keyword,
+            before_packages,
+            after_packages,
+            before_imports,
+            after_imports,
+            before_provides: provides.before_provides_keyword,
+            after_provides: provides.after_provides_keyword,
+            before_to: provides.before_to_keyword,
+            after_to: provides.after_to_keyword,
+        };
+
+        Ok((MadeProgress, header, state))
+    }
 }
 
 #[inline(always)]
-pub fn platform_header<'a>() -> impl Parser<'a, PlatformHeader<'a>, SyntaxError<'a>> {
-    parser::map(
-        and!(
-            skip_first!(
-                ascii_string("platform"),
-                and!(space1(1), loc!(package_name()))
-            ),
-            and!(
-                and!(
-                    and!(requires(), and!(exposes_modules(), packages())),
-                    and!(imports(), provides_without_to())
-                ),
-                effects()
-            )
-        ),
-        |(
-            (after_platform_keyword, name),
-            (
-                (
-                    (
-                        ((before_requires, after_requires), requires),
-                        (((before_exposes, after_exposes), exposes), packages),
-                    ),
-                    (
-                        ((before_imports, after_imports), imports),
-                        ((before_provides, after_provides), provides),
-                    ),
-                ),
-                effects,
-            ),
-        )| {
-            PlatformHeader {
-                name,
-                requires,
-                exposes,
-                packages: packages.entries,
-                imports,
-                provides,
-                effects,
-                after_platform_keyword,
-                before_requires,
-                after_requires,
-                before_exposes,
-                after_exposes,
-                before_packages: packages.before_packages_keyword,
-                after_packages: packages.after_packages_keyword,
-                before_imports,
-                after_imports,
-                before_provides,
-                after_provides,
-            }
-        },
-    )
+fn platform_header<'a>() -> impl Parser<'a, PlatformHeader<'a>, SyntaxError<'a>> {
+    |arena, state| {
+        let (_, after_platform_keyword, state) = space1(1).parse(arena, state)?;
+        let (_, name, state) = loc!(package_name()).parse(arena, state)?;
+
+        let (_, ((before_requires, after_requires), requires), state) =
+            requires().parse(arena, state)?;
+
+        let (_, ((before_exposes, after_exposes), exposes), state) =
+            exposes_modules().parse(arena, state)?;
+
+        let (_, packages, state) = packages().parse(arena, state)?;
+
+        let (_, ((before_imports, after_imports), imports), state) =
+            imports().parse(arena, state)?;
+
+        let (_, ((before_provides, after_provides), provides), state) =
+            provides_without_to().parse(arena, state)?;
+
+        let (_, effects, state) = effects().parse(arena, state)?;
+
+        let header = PlatformHeader {
+            name,
+            requires,
+            exposes,
+            packages: packages.entries,
+            imports,
+            provides,
+            effects,
+            after_platform_keyword,
+            before_requires,
+            after_requires,
+            before_exposes,
+            after_exposes,
+            before_packages: packages.before_packages_keyword,
+            after_packages: packages.after_packages_keyword,
+            before_imports,
+            after_imports,
+            before_provides,
+            after_provides,
+        };
+
+        Ok((MadeProgress, header, state))
+    }
 }
 
 #[inline(always)]
@@ -441,14 +420,39 @@ fn requires<'a>() -> impl Parser<
     ),
     SyntaxError<'a>,
 > {
+    specialize(
+        |e, r, c| SyntaxError::Header(EHeader::Requires(e, r, c)),
+        requires_help(),
+    )
+}
+
+#[inline(always)]
+fn requires_help<'a>() -> impl Parser<
+    'a,
+    (
+        (&'a [CommentOrNewline<'a>], &'a [CommentOrNewline<'a>]),
+        Vec<'a, Located<TypedIdent<'a>>>,
+    ),
+    ERequires<'a>,
+> {
+    let min_indent = 1;
     and!(
-        and!(skip_second!(space1(1), ascii_string("requires")), space1(1)),
-        collection!(
-            ascii_char(b'{'),
-            loc!(typed_ident()),
-            ascii_char(b','),
-            ascii_char(b'}'),
-            1
+        spaces_around_keyword(
+            min_indent,
+            "requires",
+            ERequires::Requires,
+            ERequires::Space,
+            ERequires::IndentRequires,
+            ERequires::IndentListStart
+        ),
+        collection_e!(
+            word1(b'{', ERequires::ListStart),
+            specialize(ERequires::TypedIdent, loc!(typed_ident_help())),
+            word1(b',', ERequires::ListEnd),
+            word1(b'}', ERequires::ListEnd),
+            min_indent,
+            ERequires::Space,
+            ERequires::IndentListEnd
         )
     )
 }
@@ -729,6 +733,41 @@ fn typed_ident<'a>() -> impl Parser<'a, TypedIdent<'a>, SyntaxError<'a>> {
     }
 }
 
+fn typed_ident_help<'a>() -> impl Parser<'a, TypedIdent<'a>, ETypedIdent<'a>> {
+    // e.g.
+    //
+    // printLine : Str -> Effect {}
+    let min_indent = 0;
+
+    map!(
+        and!(
+            and!(
+                loc!(specialize(
+                    |_, r, c| ETypedIdent::Identifier(r, c),
+                    lowercase_ident()
+                )),
+                space0_e(min_indent, ETypedIdent::Space, ETypedIdent::IndentHasType)
+            ),
+            skip_first!(
+                word1(b':', ETypedIdent::HasType),
+                space0_before_e(
+                    specialize(ETypedIdent::Type, type_annotation::located_help(min_indent)),
+                    min_indent,
+                    ETypedIdent::Space,
+                    ETypedIdent::IndentType,
+                )
+            )
+        ),
+        |((ident, spaces_before_colon), ann)| {
+            TypedIdent::Entry {
+                ident,
+                spaces_before_colon,
+                ann,
+            }
+        }
+    )
+}
+
 fn shortname<'a>() -> impl Parser<'a, &'a str, EImports> {
     specialize(|_, r, c| EImports::Shortname(r, c), lowercase_ident())
 }
diff --git a/compiler/parse/src/parser.rs b/compiler/parse/src/parser.rs
index 1d831bbf6b..affb41567b 100644
--- a/compiler/parse/src/parser.rs
+++ b/compiler/parse/src/parser.rs
@@ -334,15 +334,16 @@ pub enum SyntaxError<'a> {
     Type(Type<'a>),
     Pattern(EPattern<'a>),
     Expr(EExpr<'a>),
-    Header(EHeader),
+    Header(EHeader<'a>),
     Space(BadInputError),
 }
 
-#[derive(Debug, Clone, Copy, PartialEq, Eq)]
-pub enum EHeader {
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub enum EHeader<'a> {
     Provides(EProvides, Row, Col),
     Exposes(EExposes, Row, Col),
     Imports(EImports, Row, Col),
+    Requires(ERequires<'a>, Row, Col),
 }
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
@@ -373,6 +374,29 @@ pub enum EExposes {
     Space(BadInputError, Row, Col),
 }
 
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub enum ERequires<'a> {
+    Requires(Row, Col),
+    IndentRequires(Row, Col),
+    IndentListStart(Row, Col),
+    IndentListEnd(Row, Col),
+    ListStart(Row, Col),
+    ListEnd(Row, Col),
+    TypedIdent(ETypedIdent<'a>, Row, Col),
+    Space(BadInputError, Row, Col),
+}
+
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub enum ETypedIdent<'a> {
+    Space(BadInputError, Row, Col),
+    HasType(Row, Col),
+    IndentHasType(Row, Col),
+    Name(Row, Col),
+    Type(Type<'a>, Row, Col),
+    IndentType(Row, Col),
+    Identifier(Row, Col),
+}
+
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
 pub enum EImports {
     Imports(Row, Col),
diff --git a/compiler/parse/tests/test_parse.rs b/compiler/parse/tests/test_parse.rs
index f48d03df13..084f169f12 100644
--- a/compiler/parse/tests/test_parse.rs
+++ b/compiler/parse/tests/test_parse.rs
@@ -23,14 +23,12 @@ mod test_parse {
     use roc_parse::ast::Pattern::{self, *};
     use roc_parse::ast::StrLiteral::{self, *};
     use roc_parse::ast::StrSegment::*;
-    use roc_parse::ast::{
-        self, Attempting, Def, EscapedChar, Spaceable, TypeAnnotation, WhenBranch,
-    };
+    use roc_parse::ast::{self, Def, EscapedChar, Spaceable, TypeAnnotation, WhenBranch};
     use roc_parse::header::{
         AppHeader, Effects, ExposesEntry, ImportsEntry, InterfaceHeader, ModuleName, PackageEntry,
         PackageName, PackageOrPath, PlatformHeader, To,
     };
-    use roc_parse::module::{app_header, interface_header, module_defs, platform_header};
+    use roc_parse::module::module_defs;
     use roc_parse::parser::{Parser, State, SyntaxError};
     use roc_parse::test_helpers::parse_expr_with;
     use roc_region::all::{Located, Region};
@@ -43,10 +41,9 @@ mod test_parse {
         assert_eq!(Ok(expected_expr), actual);
     }
 
-    fn assert_parsing_fails<'a>(input: &'a str, _reason: SyntaxError, _attempting: Attempting) {
+    fn assert_parsing_fails<'a>(input: &'a str, _reason: SyntaxError) {
         let arena = Bump::new();
         let actual = parse_expr_with(&arena, input);
-        // let expected_fail = Fail { reason, attempting };
 
         assert!(actual.is_err());
     }
@@ -291,7 +288,7 @@ mod test_parse {
 
     #[test]
     fn empty_source_file() {
-        assert_parsing_fails("", SyntaxError::Eof(Region::zero()), Attempting::Module);
+        assert_parsing_fails("", SyntaxError::Eof(Region::zero()));
     }
 
     #[test]
@@ -308,11 +305,7 @@ mod test_parse {
         // Make sure it's longer than our maximum line length
         assert_eq!(too_long_str.len(), max_line_length + 1);
 
-        assert_parsing_fails(
-            &too_long_str,
-            SyntaxError::LineTooLong(0),
-            Attempting::Module,
-        );
+        assert_parsing_fails(&too_long_str, SyntaxError::LineTooLong(0));
     }
 
     // INT LITERALS
@@ -2416,7 +2409,7 @@ mod test_parse {
         let imports = Vec::new_in(&arena);
         let provides = Vec::new_in(&arena);
         let module_name = StrLiteral::PlainLine("test-app");
-        let expected = AppHeader {
+        let header = AppHeader {
             name: Located::new(0, 0, 4, 14, module_name),
             packages,
             imports,
@@ -2433,16 +2426,15 @@ mod test_parse {
             after_to: &[],
         };
 
+        let expected = roc_parse::ast::Module::App { header };
+
         let src = indoc!(
             r#"
                 app "test-app" packages {} imports [] provides [] to blah
             "#
         );
-        let actual = app_header()
-            .parse(
-                &arena,
-                State::new_in(&arena, src.as_bytes(), Attempting::Module),
-            )
+        let actual = roc_parse::module::header()
+            .parse(&arena, State::new_in(&arena, src.as_bytes()))
             .map(|tuple| tuple.1);
 
         assert_eq!(Ok(expected), actual);
@@ -2457,7 +2449,7 @@ mod test_parse {
         let imports = Vec::new_in(&arena);
         let provides = Vec::new_in(&arena);
         let module_name = StrLiteral::PlainLine("test-app");
-        let expected = AppHeader {
+        let header = AppHeader {
             name: Located::new(0, 0, 4, 14, module_name),
             packages,
             imports,
@@ -2474,16 +2466,16 @@ mod test_parse {
             after_to: &[],
         };
 
+        let expected = roc_parse::ast::Module::App { header };
+
         let src = indoc!(
             r#"
                 app "test-app" provides [] to "./blah"
             "#
         );
-        let actual = app_header()
-            .parse(
-                &arena,
-                State::new_in(&arena, src.as_bytes(), Attempting::Module),
-            )
+
+        let actual = roc_parse::module::header()
+            .parse(&arena, State::new_in(&arena, src.as_bytes()))
             .map(|tuple| tuple.1);
 
         assert_eq!(Ok(expected), actual);
@@ -2509,7 +2501,8 @@ mod test_parse {
         let provide_entry = Located::new(3, 3, 15, 24, Exposed("quicksort"));
         let provides = bumpalo::vec![in &arena; provide_entry];
         let module_name = StrLiteral::PlainLine("quicksort");
-        let expected = AppHeader {
+
+        let header = AppHeader {
             name: Located::new(0, 0, 4, 15, module_name),
             packages,
             imports,
@@ -2526,6 +2519,8 @@ mod test_parse {
             after_to: &[],
         };
 
+        let expected = roc_parse::ast::Module::App { header };
+
         let src = indoc!(
             r#"
                 app "quicksort"
@@ -2535,11 +2530,8 @@ mod test_parse {
             "#
         );
 
-        let actual = app_header()
-            .parse(
-                &arena,
-                State::new_in(&arena, src.as_bytes(), Attempting::Module),
-            )
+        let actual = roc_parse::module::header()
+            .parse(&arena, State::new_in(&arena, src.as_bytes()))
             .map(|tuple| tuple.1);
 
         assert_eq!(Ok(expected), actual);
@@ -2560,7 +2552,7 @@ mod test_parse {
             spaces_after_effects_keyword: &[],
             spaces_after_type_name: &[],
         };
-        let expected = PlatformHeader {
+        let header = PlatformHeader {
             name: Located::new(0, 0, 9, 23, pkg_name),
             requires: Vec::new_in(&arena),
             exposes: Vec::new_in(&arena),
@@ -2581,12 +2573,11 @@ mod test_parse {
             after_provides: &[],
         };
 
+        let expected = roc_parse::ast::Module::Platform { header };
+
         let src = "platform rtfeldman/blah requires {} exposes [] packages {} imports [] provides [] effects fx.Blah {}";
-        let actual = platform_header()
-            .parse(
-                &arena,
-                State::new_in(&arena, src.as_bytes(), Attempting::Module),
-            )
+        let actual = roc_parse::module::header()
+            .parse(&arena, State::new_in(&arena, src.as_bytes()))
             .map(|tuple| tuple.1);
 
         assert_eq!(Ok(expected), actual);
@@ -2621,7 +2612,7 @@ mod test_parse {
             spaces_after_effects_keyword: &[],
             spaces_after_type_name: &[],
         };
-        let expected = PlatformHeader {
+        let header = PlatformHeader {
             name: Located::new(0, 0, 9, 19, pkg_name),
             requires: Vec::new_in(&arena),
             exposes: Vec::new_in(&arena),
@@ -2642,6 +2633,8 @@ mod test_parse {
             after_provides: &[],
         };
 
+        let expected = roc_parse::ast::Module::Platform { header };
+
         let src = indoc!(
             r#"
                 platform foo/barbaz
@@ -2653,11 +2646,8 @@ mod test_parse {
                     effects fx.Effect {}
             "#
         );
-        let actual = platform_header()
-            .parse(
-                &arena,
-                State::new_in(&arena, src.as_bytes(), Attempting::Module),
-            )
+        let actual = roc_parse::module::header()
+            .parse(&arena, State::new_in(&arena, src.as_bytes()))
             .map(|tuple| tuple.1);
 
         assert_eq!(Ok(expected), actual);
@@ -2669,7 +2659,7 @@ mod test_parse {
         let exposes = Vec::new_in(&arena);
         let imports = Vec::new_in(&arena);
         let module_name = ModuleName::new("Foo");
-        let expected = InterfaceHeader {
+        let header = InterfaceHeader {
             name: Located::new(0, 0, 10, 13, module_name),
             exposes,
             imports,
@@ -2680,16 +2670,16 @@ mod test_parse {
             before_imports: &[],
             after_imports: &[],
         };
+
+        let expected = roc_parse::ast::Module::Interface { header };
+
         let src = indoc!(
             r#"
                 interface Foo exposes [] imports []
             "#
         );
-        let actual = interface_header()
-            .parse(
-                &arena,
-                State::new_in(&arena, src.as_bytes(), Attempting::Module),
-            )
+        let actual = roc_parse::module::header()
+            .parse(&arena, State::new_in(&arena, src.as_bytes()))
             .map(|tuple| tuple.1);
 
         assert_eq!(Ok(expected), actual);
@@ -2701,7 +2691,7 @@ mod test_parse {
         let exposes = Vec::new_in(&arena);
         let imports = Vec::new_in(&arena);
         let module_name = ModuleName::new("Foo.Bar.Baz");
-        let expected = InterfaceHeader {
+        let header = InterfaceHeader {
             name: Located::new(0, 0, 10, 21, module_name),
             exposes,
             imports,
@@ -2712,16 +2702,16 @@ mod test_parse {
             before_imports: &[],
             after_imports: &[],
         };
+
+        let expected = roc_parse::ast::Module::Interface { header };
+
         let src = indoc!(
             r#"
                 interface Foo.Bar.Baz exposes [] imports []
             "#
         );
-        let actual = interface_header()
-            .parse(
-                &arena,
-                State::new_in(&arena, src.as_bytes(), Attempting::Module),
-            )
+        let actual = roc_parse::module::header()
+            .parse(&arena, State::new_in(&arena, src.as_bytes()))
             .map(|tuple| tuple.1);
 
         assert_eq!(Ok(expected), actual);
@@ -2748,10 +2738,7 @@ mod test_parse {
             "#
         );
         let actual = module_defs()
-            .parse(
-                &arena,
-                State::new_in(&arena, src.as_bytes(), Attempting::Module),
-            )
+            .parse(&arena, State::new_in(&arena, src.as_bytes()))
             .map(|tuple| tuple.1);
 
         // It should occur twice in the debug output - once for the pattern,
@@ -2810,10 +2797,7 @@ mod test_parse {
         );
 
         let actual = module_defs()
-            .parse(
-                &arena,
-                State::new_in(&arena, src.as_bytes(), Attempting::Module),
-            )
+            .parse(&arena, State::new_in(&arena, src.as_bytes()))
             .map(|tuple| tuple.1);
 
         assert_eq!(Ok(expected), actual);
@@ -2833,10 +2817,7 @@ mod test_parse {
         );
 
         let actual = module_defs()
-            .parse(
-                &arena,
-                State::new_in(&arena, src.as_bytes(), Attempting::Module),
-            )
+            .parse(&arena, State::new_in(&arena, src.as_bytes()))
             .map(|tuple| tuple.1);
 
         assert!(actual.is_ok());
@@ -2858,10 +2839,7 @@ mod test_parse {
         );
 
         let actual = module_defs()
-            .parse(
-                &arena,
-                State::new_in(&arena, src.as_bytes(), Attempting::Module),
-            )
+            .parse(&arena, State::new_in(&arena, src.as_bytes()))
             .map(|tuple| tuple.1);
 
         assert!(actual.is_ok());
@@ -2882,10 +2860,7 @@ mod test_parse {
         );
 
         let actual = module_defs()
-            .parse(
-                &arena,
-                State::new_in(&arena, src.as_bytes(), Attempting::Module),
-            )
+            .parse(&arena, State::new_in(&arena, src.as_bytes()))
             .map(|tuple| tuple.1);
 
         dbg!(&actual);
diff --git a/compiler/reporting/src/error/parse.rs b/compiler/reporting/src/error/parse.rs
index 93eebfcdf8..732e261e17 100644
--- a/compiler/reporting/src/error/parse.rs
+++ b/compiler/reporting/src/error/parse.rs
@@ -2473,23 +2473,27 @@ fn to_tapply_report<'a>(
 fn to_header_report<'a>(
     alloc: &'a RocDocAllocator<'a>,
     filename: PathBuf,
-    parse_problem: &roc_parse::parser::EHeader,
+    parse_problem: &roc_parse::parser::EHeader<'a>,
     _start_row: Row,
     _start_col: Col,
 ) -> Report<'a> {
     use roc_parse::parser::EHeader;
 
-    match *parse_problem {
+    match parse_problem {
         EHeader::Provides(provides, row, col) => {
-            to_provides_report(alloc, filename, &provides, row, col)
+            to_provides_report(alloc, filename, &provides, *row, *col)
         }
 
         EHeader::Exposes(exposes, row, col) => {
-            to_exposes_report(alloc, filename, &exposes, row, col)
+            to_exposes_report(alloc, filename, &exposes, *row, *col)
         }
 
         EHeader::Imports(imports, row, col) => {
-            to_imports_report(alloc, filename, &imports, row, col)
+            to_imports_report(alloc, filename, &imports, *row, *col)
+        }
+
+        EHeader::Requires(requires, row, col) => {
+            to_requires_report(alloc, filename, &requires, *row, *col)
         }
     }
 }
@@ -2684,6 +2688,46 @@ fn to_imports_report<'a>(
     }
 }
 
+fn to_requires_report<'a>(
+    alloc: &'a RocDocAllocator<'a>,
+    filename: PathBuf,
+    parse_problem: &roc_parse::parser::ERequires<'a>,
+    start_row: Row,
+    start_col: Col,
+) -> Report<'a> {
+    use roc_parse::parser::ERequires;
+
+    match *parse_problem {
+        ERequires::Requires(row, col) => {
+            let surroundings = Region::from_rows_cols(start_row, start_col, row, col);
+            let region = Region::from_row_col(row, col);
+
+            let doc = alloc.stack(vec![
+                alloc.reflow(r"I am in the middle of a header, but I got stuck here:"),
+                alloc.region_with_subregion(surroundings, region),
+                alloc.concat(vec![
+                    alloc.reflow("I am expecting the "),
+                    alloc.keyword("requires"),
+                    alloc.reflow(" keyword next, like "),
+                ]),
+                alloc
+                    .parser_suggestion("requires { main : Task I64 Str }")
+                    .indent(4),
+            ]);
+
+            Report {
+                filename,
+                doc,
+                title: "MISSING REQUIRES".to_string(),
+            }
+        }
+
+        ERequires::Space(error, row, col) => to_space_report(alloc, filename, &error, row, col),
+
+        _ => todo!("unhandled parse error {:?}", parse_problem),
+    }
+}
+
 fn to_space_report<'a>(
     alloc: &'a RocDocAllocator<'a>,
     filename: PathBuf,

From a80c429a0a27b9f1ee260e475783447bb7a87170 Mon Sep 17 00:00:00 2001
From: Anton-4 <17049058+Anton-4@users.noreply.github.com>
Date: Tue, 9 Mar 2021 18:41:32 +0100
Subject: [PATCH 19/74] replace ; with && to prevent discarding of exit codes

---
 Earthfile | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/Earthfile b/Earthfile
index d4f41a014c..dc8254fb15 100644
--- a/Earthfile
+++ b/Earthfile
@@ -30,10 +30,10 @@ install-zig-llvm-valgrind-clippy-rustfmt:
     RUN wget https://sourceware.org/pub/valgrind/valgrind-3.16.1.tar.bz2
     RUN tar -xf valgrind-3.16.1.tar.bz2
     # need to cd every time, every command starts at WORKDIR
-    RUN cd valgrind-3.16.1; ./autogen.sh
-    RUN cd valgrind-3.16.1; ./configure --disable-dependency-tracking
-    RUN cd valgrind-3.16.1; make -j`nproc`
-    RUN cd valgrind-3.16.1; make install
+    RUN cd valgrind-3.16.1 && ./autogen.sh
+    RUN cd valgrind-3.16.1 && ./configure --disable-dependency-tracking
+    RUN cd valgrind-3.16.1 && make -j`nproc`
+    RUN cd valgrind-3.16.1 && make install
     # clippy
     RUN rustup component add clippy
     # rustfmt
@@ -75,16 +75,16 @@ save-cache:
     FROM +install-zig-llvm-valgrind-clippy-rustfmt
     COPY +prepare-cache/recipe.json ./
     RUN --mount=type=cache,target=$SCCACHE_DIR \
-        cargo chef cook; sccache --show-stats # for clippy
+        cargo chef cook && sccache --show-stats # for clippy
     RUN --mount=type=cache,target=$SCCACHE_DIR \
-        cargo chef cook --release --tests; sccache --show-stats
+        cargo chef cook --release --tests && sccache --show-stats
     SAVE ARTIFACT target
     SAVE ARTIFACT $CARGO_HOME cargo_home
 
 test-zig:
     FROM +install-zig-llvm-valgrind-clippy-rustfmt
     COPY --dir compiler/builtins/bitcode ./
-    RUN cd bitcode; ./run-tests.sh;
+    RUN cd bitcode && ./run-tests.sh
 
 check-clippy:
     FROM +copy-dirs-and-cache
@@ -101,7 +101,7 @@ test-rust:
     FROM +copy-dirs-and-cache
     ENV RUST_BACKTRACE=1
     RUN --mount=type=cache,target=$SCCACHE_DIR \
-        cargo test --release; sccache --show-stats
+        cargo test --release && sccache --show-stats
 
 test-all:
     BUILD +test-zig

From 3c70eca1452ec497510767e2525859af5dcd8c03 Mon Sep 17 00:00:00 2001
From: Folkert <folkert@folkertdev.nl>
Date: Tue, 9 Mar 2021 18:51:56 +0100
Subject: [PATCH 20/74] refactor

---
 compiler/parse/src/module.rs | 18 +++++++++++++-----
 compiler/parse/src/parser.rs |  4 ++++
 2 files changed, 17 insertions(+), 5 deletions(-)

diff --git a/compiler/parse/src/module.rs b/compiler/parse/src/module.rs
index 6a51c34c67..cdd2b44af8 100644
--- a/compiler/parse/src/module.rs
+++ b/compiler/parse/src/module.rs
@@ -37,14 +37,22 @@ pub fn header<'a>() -> impl Parser<'a, Module<'a>, SyntaxError<'a>> {
 
 #[inline(always)]
 fn interface_header<'a>() -> impl Parser<'a, InterfaceHeader<'a>, SyntaxError<'a>> {
+    specialize(|e, _, _| SyntaxError::Header(e), interface_header_help())
+}
+
+#[inline(always)]
+fn interface_header_help<'a>() -> impl Parser<'a, InterfaceHeader<'a>, EHeader<'a>> {
     |arena, state| {
-        let (_, after_interface_keyword, state) = space1(1).parse(arena, state)?;
-        let (_, name, state) = loc!(module_name()).parse(arena, state)?;
+        let min_indent = 1;
+
+        let (_, after_interface_keyword, state) =
+            space0_e(min_indent, EHeader::Space, EHeader::IndentStart).parse(arena, state)?;
+        let (_, name, state) = loc!(module_name_help(EHeader::ModuleName)).parse(arena, state)?;
 
         let (_, ((before_exposes, after_exposes), exposes), state) =
-            exposes_values().parse(arena, state)?;
+            specialize(EHeader::Exposes, exposes_values_help()).parse(arena, state)?;
         let (_, ((before_imports, after_imports), imports), state) =
-            imports().parse(arena, state)?;
+            specialize(EHeader::Imports, imports_help()).parse(arena, state)?;
 
         let header = InterfaceHeader {
             name,
@@ -532,7 +540,7 @@ where
 {
     and!(
         skip_second!(
-            space0_e(min_indent, space_problem, indent_problem1),
+            backtrackable(space0_e(min_indent, space_problem, indent_problem1)),
             crate::parser::keyword_e(keyword, expectation)
         ),
         space0_e(min_indent, space_problem, indent_problem2)
diff --git a/compiler/parse/src/parser.rs b/compiler/parse/src/parser.rs
index affb41567b..0627fcf2d1 100644
--- a/compiler/parse/src/parser.rs
+++ b/compiler/parse/src/parser.rs
@@ -344,6 +344,10 @@ pub enum EHeader<'a> {
     Exposes(EExposes, Row, Col),
     Imports(EImports, Row, Col),
     Requires(ERequires<'a>, Row, Col),
+
+    Space(BadInputError, Row, Col),
+    ModuleName(Row, Col),
+    IndentStart(Row, Col),
 }
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]

From e96a0215bec0b6d01524a6b83ac7c6dbf326ca8e Mon Sep 17 00:00:00 2001
From: Folkert <folkert@folkertdev.nl>
Date: Tue, 9 Mar 2021 20:38:58 +0100
Subject: [PATCH 21/74] more errors for headers

---
 compiler/reporting/src/error/parse.rs      | 31 ++++++++++++++++++++--
 compiler/reporting/tests/test_reporting.rs | 26 ++++++++++++++++++
 2 files changed, 55 insertions(+), 2 deletions(-)

diff --git a/compiler/reporting/src/error/parse.rs b/compiler/reporting/src/error/parse.rs
index 732e261e17..73f5829161 100644
--- a/compiler/reporting/src/error/parse.rs
+++ b/compiler/reporting/src/error/parse.rs
@@ -2474,8 +2474,8 @@ fn to_header_report<'a>(
     alloc: &'a RocDocAllocator<'a>,
     filename: PathBuf,
     parse_problem: &roc_parse::parser::EHeader<'a>,
-    _start_row: Row,
-    _start_col: Col,
+    start_row: Row,
+    start_col: Col,
 ) -> Report<'a> {
     use roc_parse::parser::EHeader;
 
@@ -2495,6 +2495,33 @@ fn to_header_report<'a>(
         EHeader::Requires(requires, row, col) => {
             to_requires_report(alloc, filename, &requires, *row, *col)
         }
+
+        EHeader::IndentStart(row, col) => todo!(),
+
+        EHeader::ModuleName(row, col) => {
+            let surroundings = Region::from_rows_cols(start_row, start_col, *row, *col);
+            let region = Region::from_row_col(*row, *col);
+
+            let doc = alloc.stack(vec![
+                alloc.reflow(r"I am partway through parsing a header, but got stuck here:"),
+                alloc.region_with_subregion(surroundings, region),
+                alloc.concat(vec![
+                    alloc.reflow("I am expecting a module name next, like "),
+                    alloc.parser_suggestion("BigNum"),
+                    alloc.reflow(" or "),
+                    alloc.parser_suggestion("Main"),
+                    alloc.reflow(". Module names must start with an uppercase letter."),
+                ]),
+            ]);
+
+            Report {
+                filename,
+                doc,
+                title: "WEIRD MODULE NAME".to_string(),
+            }
+        }
+
+        EHeader::Space(error, row, col) => to_space_report(alloc, filename, &error, *row, *col),
     }
 }
 
diff --git a/compiler/reporting/tests/test_reporting.rs b/compiler/reporting/tests/test_reporting.rs
index bef4e30107..d24ff00022 100644
--- a/compiler/reporting/tests/test_reporting.rs
+++ b/compiler/reporting/tests/test_reporting.rs
@@ -5813,4 +5813,30 @@ mod test_reporting {
             ),
         )
     }
+
+    #[test]
+    fn invalid_module_name() {
+        report_header_problem_as(
+            indoc!(
+                r#"
+                interface foobar 
+                    exposes [ main, @Foo ]
+                    imports [base.Task, Base64 ]
+                "#
+            ),
+            indoc!(
+                r#"
+                ── WEIRD MODULE NAME ───────────────────────────────────────────────────────────
+                
+                I am partway through parsing a header, but got stuck here:
+                
+                1│  interface foobar 
+                              ^
+                
+                I am expecting a module name next, like BigNum or Main. Module names
+                must start with an uppercase letter.
+            "#
+            ),
+        )
+    }
 }

From caafcc28889d45dfb098fb03f52ad71a40dae4e7 Mon Sep 17 00:00:00 2001
From: Folkert <folkert@folkertdev.nl>
Date: Tue, 9 Mar 2021 20:40:19 +0100
Subject: [PATCH 22/74] cleanup

---
 compiler/parse/src/module.rs | 25 ++++---------------------
 1 file changed, 4 insertions(+), 21 deletions(-)

diff --git a/compiler/parse/src/module.rs b/compiler/parse/src/module.rs
index cdd2b44af8..efa13d2cc3 100644
--- a/compiler/parse/src/module.rs
+++ b/compiler/parse/src/module.rs
@@ -8,9 +8,9 @@ use crate::header::{
 use crate::ident::{lowercase_ident, unqualified_ident, uppercase_ident};
 use crate::parser::Progress::{self, *};
 use crate::parser::{
-    self, ascii_char, ascii_string, backtrackable, end_of_file, loc, optional, peek_utf8_char,
-    peek_utf8_char_at, specialize, unexpected, unexpected_eof, word1, Col, EExposes, EHeader,
-    EImports, EProvides, ERequires, ETypedIdent, ParseResult, Parser, Row, State, SyntaxError,
+    ascii_char, ascii_string, backtrackable, end_of_file, loc, peek_utf8_char, peek_utf8_char_at,
+    specialize, unexpected, unexpected_eof, word1, Col, EExposes, EHeader, EImports, EProvides,
+    ERequires, ETypedIdent, ParseResult, Parser, Row, State, SyntaxError,
 };
 use crate::string_literal;
 use crate::type_annotation;
@@ -50,7 +50,7 @@ fn interface_header_help<'a>() -> impl Parser<'a, InterfaceHeader<'a>, EHeader<'
         let (_, name, state) = loc!(module_name_help(EHeader::ModuleName)).parse(arena, state)?;
 
         let (_, ((before_exposes, after_exposes), exposes), state) =
-            specialize(EHeader::Exposes, exposes_values_help()).parse(arena, state)?;
+            specialize(EHeader::Exposes, exposes_values()).parse(arena, state)?;
         let (_, ((before_imports, after_imports), imports), state) =
             specialize(EHeader::Imports, imports_help()).parse(arena, state)?;
 
@@ -90,8 +90,6 @@ fn parse_package_part<'a>(
     arena: &'a Bump,
     mut state: State<'a>,
 ) -> ParseResult<'a, &'a str, SyntaxError<'a>> {
-    use encode_unicode::CharExt;
-
     let mut part_buf = String::new_in(arena); // The current "part" (parts are dot-separated.)
 
     while !state.bytes.is_empty() {
@@ -467,21 +465,6 @@ fn requires_help<'a>() -> impl Parser<
 
 #[inline(always)]
 fn exposes_values<'a>() -> impl Parser<
-    'a,
-    (
-        (&'a [CommentOrNewline<'a>], &'a [CommentOrNewline<'a>]),
-        Vec<'a, Located<ExposesEntry<'a, &'a str>>>,
-    ),
-    SyntaxError<'a>,
-> {
-    specialize(
-        |e, r, c| SyntaxError::Header(EHeader::Exposes(e, r, c)),
-        exposes_values_help(),
-    )
-}
-
-#[inline(always)]
-fn exposes_values_help<'a>() -> impl Parser<
     'a,
     (
         (&'a [CommentOrNewline<'a>], &'a [CommentOrNewline<'a>]),

From 3eddedc56654d28a007860006fae6537913e49d3 Mon Sep 17 00:00:00 2001
From: Folkert <folkert@folkertdev.nl>
Date: Tue, 9 Mar 2021 21:53:23 +0100
Subject: [PATCH 23/74] port effects

---
 compiler/parse/src/header.rs               |  58 ++++++-
 compiler/parse/src/module.rs               | 186 ++++++++++++---------
 compiler/parse/src/parser.rs               |  32 +++-
 compiler/reporting/src/error/parse.rs      | 142 +++++++++++++---
 compiler/reporting/tests/test_reporting.rs |  26 +++
 5 files changed, 340 insertions(+), 104 deletions(-)

diff --git a/compiler/parse/src/header.rs b/compiler/parse/src/header.rs
index d90501564b..e289e15179 100644
--- a/compiler/parse/src/header.rs
+++ b/compiler/parse/src/header.rs
@@ -1,13 +1,14 @@
+use crate::ast::{CommentOrNewline, Spaceable, StrLiteral, TypeAnnotation};
 use crate::blankspace::space0;
 use crate::ident::lowercase_ident;
-use crate::module::package_name;
-use crate::parser::{ascii_char, optional, Either, Parser, Progress::*, State, SyntaxError};
-use crate::string_literal;
-use crate::{
-    ast::{CommentOrNewline, Spaceable, StrLiteral, TypeAnnotation},
-    parser::specialize,
+use crate::parser::{
+    ascii_char, optional, peek_utf8_char, specialize, unexpected_eof, Either, ParseResult, Parser,
+    Progress, Progress::*, State, SyntaxError,
 };
+use crate::string_literal;
+use bumpalo::collections::String;
 use bumpalo::collections::Vec;
+use bumpalo::Bump;
 use inlinable_string::InlinableString;
 use roc_region::all::Loc;
 
@@ -296,3 +297,48 @@ pub fn package_or_path<'a>() -> impl Parser<'a, PackageOrPath<'a>, SyntaxError<'
 fn package_version<'a>() -> impl Parser<'a, Version<'a>, SyntaxError<'a>> {
     move |_, _| todo!("TODO parse package version")
 }
+
+#[inline(always)]
+pub fn package_name<'a>() -> impl Parser<'a, PackageName<'a>, SyntaxError<'a>> {
+    // e.g. rtfeldman/blah
+    //
+    // Package names and accounts can be capitalized and can contain dashes.
+    // They cannot contain underscores or other special characters.
+    // They must be ASCII.
+
+    map!(
+        and!(
+            parse_package_part,
+            skip_first!(ascii_char(b'/'), parse_package_part)
+        ),
+        |(account, pkg)| { PackageName { account, pkg } }
+    )
+}
+
+fn parse_package_part<'a>(
+    arena: &'a Bump,
+    mut state: State<'a>,
+) -> ParseResult<'a, &'a str, SyntaxError<'a>> {
+    let mut part_buf = String::new_in(arena); // The current "part" (parts are dot-separated.)
+
+    while !state.bytes.is_empty() {
+        match peek_utf8_char(&state) {
+            Ok((ch, bytes_parsed)) => {
+                if ch == '-' || ch.is_ascii_alphanumeric() {
+                    part_buf.push(ch);
+
+                    state = state.advance_without_indenting(bytes_parsed)?;
+                } else {
+                    let progress = Progress::progress_when(!part_buf.is_empty());
+                    return Ok((progress, part_buf.into_bump_str(), state));
+                }
+            }
+            Err(reason) => {
+                let progress = Progress::progress_when(!part_buf.is_empty());
+                return state.fail(arena, progress, reason);
+            }
+        }
+    }
+
+    Err(unexpected_eof(arena, state, 0))
+}
diff --git a/compiler/parse/src/module.rs b/compiler/parse/src/module.rs
index efa13d2cc3..7b25e80def 100644
--- a/compiler/parse/src/module.rs
+++ b/compiler/parse/src/module.rs
@@ -2,20 +2,19 @@ use crate::ast::{Attempting, CommentOrNewline, Def, Module};
 use crate::blankspace::{space0, space0_around, space0_before, space0_before_e, space0_e, space1};
 use crate::expr::def;
 use crate::header::{
-    package_entry, package_or_path, AppHeader, Effects, ExposesEntry, ImportsEntry,
-    InterfaceHeader, ModuleName, PackageEntry, PackageName, PlatformHeader, To, TypedIdent,
+    package_entry, package_name, package_or_path, AppHeader, Effects, ExposesEntry, ImportsEntry,
+    InterfaceHeader, ModuleName, PackageEntry, PlatformHeader, To, TypedIdent,
 };
 use crate::ident::{lowercase_ident, unqualified_ident, uppercase_ident};
 use crate::parser::Progress::{self, *};
 use crate::parser::{
     ascii_char, ascii_string, backtrackable, end_of_file, loc, peek_utf8_char, peek_utf8_char_at,
-    specialize, unexpected, unexpected_eof, word1, Col, EExposes, EHeader, EImports, EProvides,
-    ERequires, ETypedIdent, ParseResult, Parser, Row, State, SyntaxError,
+    specialize, unexpected, word1, Col, EEffects, EExposes, EHeader, EImports, EPackages,
+    EProvides, ERequires, ETypedIdent, Parser, Row, State, SyntaxError,
 };
 use crate::string_literal;
 use crate::type_annotation;
 use bumpalo::collections::{String, Vec};
-use bumpalo::Bump;
 use roc_region::all::Located;
 
 pub fn header<'a>() -> impl Parser<'a, Module<'a>, SyntaxError<'a>> {
@@ -69,51 +68,6 @@ fn interface_header_help<'a>() -> impl Parser<'a, InterfaceHeader<'a>, EHeader<'
     }
 }
 
-#[inline(always)]
-pub fn package_name<'a>() -> impl Parser<'a, PackageName<'a>, SyntaxError<'a>> {
-    // e.g. rtfeldman/blah
-    //
-    // Package names and accounts can be capitalized and can contain dashes.
-    // They cannot contain underscores or other special characters.
-    // They must be ASCII.
-
-    map!(
-        and!(
-            parse_package_part,
-            skip_first!(ascii_char(b'/'), parse_package_part)
-        ),
-        |(account, pkg)| { PackageName { account, pkg } }
-    )
-}
-
-fn parse_package_part<'a>(
-    arena: &'a Bump,
-    mut state: State<'a>,
-) -> ParseResult<'a, &'a str, SyntaxError<'a>> {
-    let mut part_buf = String::new_in(arena); // The current "part" (parts are dot-separated.)
-
-    while !state.bytes.is_empty() {
-        match peek_utf8_char(&state) {
-            Ok((ch, bytes_parsed)) => {
-                if ch == '-' || ch.is_ascii_alphanumeric() {
-                    part_buf.push(ch);
-
-                    state = state.advance_without_indenting(bytes_parsed)?;
-                } else {
-                    let progress = Progress::progress_when(!part_buf.is_empty());
-                    return Ok((progress, part_buf.into_bump_str(), state));
-                }
-            }
-            Err(reason) => {
-                let progress = Progress::progress_when(!part_buf.is_empty());
-                return state.fail(arena, progress, reason);
-            }
-        }
-    }
-
-    Err(unexpected_eof(arena, state, 0))
-}
-
 #[inline(always)]
 pub fn module_name<'a>() -> impl Parser<'a, ModuleName<'a>, SyntaxError<'a>> {
     move |arena, mut state: State<'a>| {
@@ -184,17 +138,28 @@ pub fn module_name<'a>() -> impl Parser<'a, ModuleName<'a>, SyntaxError<'a>> {
 
 #[inline(always)]
 fn app_header<'a>() -> impl Parser<'a, AppHeader<'a>, SyntaxError<'a>> {
+    specialize(|e, _, _| SyntaxError::Header(e), app_header_help())
+}
+
+#[inline(always)]
+fn app_header_help<'a>() -> impl Parser<'a, AppHeader<'a>, EHeader<'a>> {
     |arena, state| {
-        let (_, after_app_keyword, state) = space1(1).parse(arena, state)?;
+        let min_indent = 1;
+
+        let (_, after_app_keyword, state) =
+            space0_e(min_indent, EHeader::Space, EHeader::IndentStart).parse(arena, state)?;
         let (_, name, state) = loc!(crate::parser::specialize(
-            |e, r, c| SyntaxError::Expr(crate::parser::EExpr::Str(e, r, c)),
+            EHeader::AppName,
             string_literal::parse()
         ))
         .parse(arena, state)?;
 
-        let (_, opt_pkgs, state) = maybe!(packages()).parse(arena, state)?;
-        let (_, opt_imports, state) = maybe!(imports()).parse(arena, state)?;
-        let (_, provides, state) = provides_to().parse(arena, state)?;
+        let (_, opt_pkgs, state) =
+            maybe!(specialize(EHeader::Packages, packages_help())).parse(arena, state)?;
+        let (_, opt_imports, state) =
+            maybe!(specialize(EHeader::Imports, imports_help())).parse(arena, state)?;
+        let (_, provides, state) =
+            specialize(EHeader::Provides, provides_to()).parse(arena, state)?;
 
         let (before_packages, after_packages, package_entries) = match opt_pkgs {
             Some(pkgs) => {
@@ -304,14 +269,6 @@ struct ProvidesTo<'a> {
     after_to_keyword: &'a [CommentOrNewline<'a>],
 }
 
-#[inline(always)]
-fn provides_to<'a>() -> impl Parser<'a, ProvidesTo<'a>, SyntaxError<'a>> {
-    specialize(
-        |e, r, c| SyntaxError::Header(EHeader::Provides(e, r, c)),
-        provides_to_help(),
-    )
-}
-
 fn provides_to_package<'a>() -> impl Parser<'a, To<'a>, SyntaxError<'a>> {
     one_of![
         map!(lowercase_ident(), To::ExistingPackage),
@@ -320,7 +277,7 @@ fn provides_to_package<'a>() -> impl Parser<'a, To<'a>, SyntaxError<'a>> {
 }
 
 #[inline(always)]
-fn provides_to_help<'a>() -> impl Parser<'a, ProvidesTo<'a>, EProvides> {
+fn provides_to<'a>() -> impl Parser<'a, ProvidesTo<'a>, EProvides> {
     let min_indent = 1;
 
     map!(
@@ -584,6 +541,7 @@ struct Packages<'a> {
     after_packages_keyword: &'a [CommentOrNewline<'a>],
 }
 
+/*
 #[inline(always)]
 fn packages<'a>() -> impl Parser<'a, Packages<'a>, SyntaxError<'a>> {
     map!(
@@ -609,6 +567,52 @@ fn packages<'a>() -> impl Parser<'a, Packages<'a>, SyntaxError<'a>> {
         }
     )
 }
+*/
+
+#[inline(always)]
+fn packages<'a>() -> impl Parser<'a, Packages<'a>, SyntaxError<'a>> {
+    specialize(
+        |e, r, c| SyntaxError::Header(EHeader::Packages(e, r, c)),
+        packages_help(),
+    )
+}
+
+#[inline(always)]
+fn packages_help<'a>() -> impl Parser<'a, Packages<'a>, EPackages> {
+    let min_indent = 1;
+
+    map!(
+        and!(
+            spaces_around_keyword(
+                min_indent,
+                "packages",
+                EPackages::Packages,
+                EPackages::Space,
+                EPackages::IndentPackages,
+                EPackages::IndentListStart
+            ),
+            collection_e!(
+                word1(b'{', EPackages::ListStart),
+                specialize(
+                    |_, r, c| EPackages::PackageEntry(r, c),
+                    loc!(package_entry())
+                ),
+                word1(b',', EPackages::ListEnd),
+                word1(b'}', EPackages::ListEnd),
+                min_indent,
+                EPackages::Space,
+                EPackages::IndentListEnd
+            )
+        ),
+        |((before_packages_keyword, after_packages_keyword), entries)| {
+            Packages {
+                entries,
+                before_packages_keyword,
+                after_packages_keyword,
+            }
+        }
+    )
+}
 
 #[inline(always)]
 fn imports<'a>() -> impl Parser<
@@ -659,23 +663,49 @@ fn imports_help<'a>() -> impl Parser<
 
 #[inline(always)]
 fn effects<'a>() -> impl Parser<'a, Effects<'a>, SyntaxError<'a>> {
+    specialize(
+        |e, r, c| SyntaxError::Header(EHeader::Effects(e, r, c)),
+        effects_help(),
+    )
+}
+
+#[inline(always)]
+fn effects_help<'a>() -> impl Parser<'a, Effects<'a>, EEffects<'a>> {
     move |arena, state| {
-        let (_, spaces_before_effects_keyword, state) =
-            skip_second!(space1(0), ascii_string("effects")).parse(arena, state)?;
-        let (_, spaces_after_effects_keyword, state) = space1(0).parse(arena, state)?;
+        let min_indent = 1;
+
+        let (_, (spaces_before_effects_keyword, spaces_after_effects_keyword), state) =
+            spaces_around_keyword(
+                min_indent,
+                "effects",
+                EEffects::Effects,
+                EEffects::Space,
+                EEffects::IndentEffects,
+                EEffects::IndentListStart,
+            )
+            .parse(arena, state)?;
 
         // e.g. `fx.`
-        let (_, type_shortname, state) =
-            skip_second!(lowercase_ident(), ascii_char(b'.')).parse(arena, state)?;
+        let (_, type_shortname, state) = skip_second!(
+            specialize(|_, r, c| EEffects::Shorthand(r, c), lowercase_ident()),
+            word1(b'.', EEffects::ShorthandDot)
+        )
+        .parse(arena, state)?;
 
-        let (_, (type_name, spaces_after_type_name), state) =
-            and!(uppercase_ident(), space1(0)).parse(arena, state)?;
-        let (_, entries, state) = collection!(
-            ascii_char(b'{'),
-            loc!(typed_ident()),
-            ascii_char(b','),
-            ascii_char(b'}'),
-            1
+        // the type name, e.g. Effects
+        let (_, (type_name, spaces_after_type_name), state) = and!(
+            specialize(|_, r, c| EEffects::TypeName(r, c), uppercase_ident()),
+            space0_e(min_indent, EEffects::Space, EEffects::IndentListStart)
+        )
+        .parse(arena, state)?;
+        let (_, entries, state) = collection_e!(
+            word1(b'{', EEffects::ListStart),
+            specialize(EEffects::TypedIdent, loc!(typed_ident_help())),
+            word1(b',', EEffects::ListEnd),
+            word1(b'}', EEffects::ListEnd),
+            min_indent,
+            EEffects::Space,
+            EEffects::IndentListEnd
         )
         .parse(arena, state)?;
 
@@ -760,7 +790,7 @@ fn typed_ident_help<'a>() -> impl Parser<'a, TypedIdent<'a>, ETypedIdent<'a>> {
 }
 
 fn shortname<'a>() -> impl Parser<'a, &'a str, EImports> {
-    specialize(|_, r, c| EImports::Shortname(r, c), lowercase_ident())
+    specialize(|_, r, c| EImports::Shorthand(r, c), lowercase_ident())
 }
 
 fn module_name_help<'a, F, E>(to_expectation: F) -> impl Parser<'a, ModuleName<'a>, E>
diff --git a/compiler/parse/src/parser.rs b/compiler/parse/src/parser.rs
index 0627fcf2d1..786454ac73 100644
--- a/compiler/parse/src/parser.rs
+++ b/compiler/parse/src/parser.rs
@@ -344,9 +344,12 @@ pub enum EHeader<'a> {
     Exposes(EExposes, Row, Col),
     Imports(EImports, Row, Col),
     Requires(ERequires<'a>, Row, Col),
+    Packages(EPackages, Row, Col),
+    Effects(EEffects<'a>, Row, Col),
 
     Space(BadInputError, Row, Col),
     ModuleName(Row, Col),
+    AppName(EString<'a>, Row, Col),
     IndentStart(Row, Col),
 }
 
@@ -401,6 +404,33 @@ pub enum ETypedIdent<'a> {
     Identifier(Row, Col),
 }
 
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub enum EPackages {
+    Space(BadInputError, Row, Col),
+    Packages(Row, Col),
+    IndentPackages(Row, Col),
+    ListStart(Row, Col),
+    ListEnd(Row, Col),
+    IndentListStart(Row, Col),
+    IndentListEnd(Row, Col),
+    PackageEntry(Row, Col),
+}
+
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub enum EEffects<'a> {
+    Space(BadInputError, Row, Col),
+    Effects(Row, Col),
+    IndentEffects(Row, Col),
+    ListStart(Row, Col),
+    ListEnd(Row, Col),
+    IndentListStart(Row, Col),
+    IndentListEnd(Row, Col),
+    TypedIdent(ETypedIdent<'a>, Row, Col),
+    ShorthandDot(Row, Col),
+    Shorthand(Row, Col),
+    TypeName(Row, Col),
+}
+
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
 pub enum EImports {
     Imports(Row, Col),
@@ -412,7 +442,7 @@ pub enum EImports {
     Identifier(Row, Col),
     ExposingDot(Row, Col),
     ShorthandDot(Row, Col),
-    Shortname(Row, Col),
+    Shorthand(Row, Col),
     ModuleName(Row, Col),
     Space(BadInputError, Row, Col),
     IndentSetStart(Row, Col),
diff --git a/compiler/reporting/src/error/parse.rs b/compiler/reporting/src/error/parse.rs
index 73f5829161..f5d9ea662e 100644
--- a/compiler/reporting/src/error/parse.rs
+++ b/compiler/reporting/src/error/parse.rs
@@ -205,7 +205,7 @@ fn to_expr_report<'a>(
             let region = *region;
 
             let doc = alloc.stack(vec![
-                alloc.reflow(r"I am in the middle of parsing a definition, but I got stuck here:"),
+                alloc.reflow(r"I am partway through parsing a definition, but I got stuck here:"),
                 alloc.region_with_subregion(surroundings, region),
                 alloc.concat(vec![
                     alloc.reflow("Looks like you are trying to define a function. "),
@@ -381,7 +381,7 @@ fn to_expr_report<'a>(
             let region = Region::from_row_col(*row, *col);
 
             let doc = alloc.stack(vec![
-                alloc.reflow(r"I am in the middle of parsing a definition, but I got stuck here:"),
+                alloc.reflow(r"I am partway through parsing a definition, but I got stuck here:"),
                 alloc.region_with_subregion(surroundings, region),
                 alloc.concat(vec![
                     alloc.reflow("Looks like you are trying to define a function. "),
@@ -420,7 +420,7 @@ fn to_lambda_report<'a>(
 
                 let doc = alloc.stack(vec![
                     alloc
-                        .reflow(r"I am in the middle of parsing a function argument list, but I got stuck here:"),
+                        .reflow(r"I am partway through parsing a function argument list, but I got stuck here:"),
                     alloc.region_with_subregion(surroundings, region),
                     alloc.concat(vec![
                         alloc.reflow("I was expecting a "),
@@ -441,7 +441,7 @@ fn to_lambda_report<'a>(
 
                 let doc = alloc.stack(vec![
                     alloc
-                        .reflow(r"I am in the middle of parsing a function argument list, but I got stuck here:"),
+                        .reflow(r"I am partway through parsing a function argument list, but I got stuck here:"),
                     alloc.region_with_subregion(surroundings, region),
                     alloc.concat(vec![
                         alloc.reflow("I was expecting a "),
@@ -465,7 +465,7 @@ fn to_lambda_report<'a>(
 
                 let doc = alloc.stack(vec![
                     alloc
-                        .reflow(r"I am in the middle of parsing a function argument list, but I got stuck here:"),
+                        .reflow(r"I am partway through parsing a function argument list, but I got stuck here:"),
                     alloc.region_with_subregion(surroundings, region),
                     alloc.concat(vec![
                         alloc.reflow("I was expecting a "),
@@ -486,7 +486,7 @@ fn to_lambda_report<'a>(
 
                 let doc = alloc.stack(vec![
                     alloc
-                        .reflow(r"I am in the middle of parsing a function argument list, but I got stuck here:"),
+                        .reflow(r"I am partway through parsing a function argument list, but I got stuck here:"),
                     alloc.region_with_subregion(surroundings, region),
                     alloc.concat(vec![
                         alloc.reflow("I was expecting a "),
@@ -510,7 +510,7 @@ fn to_lambda_report<'a>(
 
                 let doc = alloc.stack(vec![
                     alloc
-                        .reflow(r"I am in the middle of parsing a function argument list, but I got stuck at this comma:"),
+                        .reflow(r"I am partway through parsing a function argument list, but I got stuck at this comma:"),
                     alloc.region_with_subregion(surroundings, region),
                     alloc.concat(vec![
                         alloc.reflow("I was expecting an argument pattern before this, "),
@@ -530,7 +530,7 @@ fn to_lambda_report<'a>(
 
                 let doc = alloc.stack(vec![
                     alloc
-                        .reflow(r"I am in the middle of parsing a function argument list, but I got stuck here:"),
+                        .reflow(r"I am partway through parsing a function argument list, but I got stuck here:"),
                     alloc.region_with_subregion(surroundings, region),
                     alloc.concat(vec![
                         alloc.reflow("I was expecting an argument pattern before this, "),
@@ -2496,6 +2496,14 @@ fn to_header_report<'a>(
             to_requires_report(alloc, filename, &requires, *row, *col)
         }
 
+        EHeader::Packages(packages, row, col) => {
+            to_packages_report(alloc, filename, &packages, *row, *col)
+        }
+
+        EHeader::Effects(effects, row, col) => {
+            to_effects_report(alloc, filename, &effects, *row, *col)
+        }
+
         EHeader::IndentStart(row, col) => todo!(),
 
         EHeader::ModuleName(row, col) => {
@@ -2521,6 +2529,29 @@ fn to_header_report<'a>(
             }
         }
 
+        EHeader::AppName(_, row, col) => {
+            let surroundings = Region::from_rows_cols(start_row, start_col, *row, *col);
+            let region = Region::from_row_col(*row, *col);
+
+            let doc = alloc.stack(vec![
+                alloc.reflow(r"I am partway through parsing a header, but got stuck here:"),
+                alloc.region_with_subregion(surroundings, region),
+                alloc.concat(vec![
+                    alloc.reflow("I am expecting an application name next, like "),
+                    alloc.parser_suggestion("app \"main\""),
+                    alloc.reflow(" or "),
+                    alloc.parser_suggestion("app \"editor\""),
+                    alloc.reflow(". App names are surrounded by quotation marks."),
+                ]),
+            ]);
+
+            Report {
+                filename,
+                doc,
+                title: "WEIRD APP NAME".to_string(),
+            }
+        }
+
         EHeader::Space(error, row, col) => to_space_report(alloc, filename, &error, *row, *col),
     }
 }
@@ -2540,9 +2571,8 @@ fn to_provides_report<'a>(
             let region = Region::from_row_col(row, col);
 
             let doc = alloc.stack(vec![
-                alloc.reflow(
-                    r"I am in the middle of parsing a provides list, but I got stuck here:",
-                ),
+                alloc
+                    .reflow(r"I am partway through parsing a provides list, but I got stuck here:"),
                 alloc.region_with_subregion(surroundings, region),
                 alloc.concat(vec![alloc.reflow(
                     "I was expecting a type name, value name or function name next, like ",
@@ -2564,7 +2594,7 @@ fn to_provides_report<'a>(
             let region = Region::from_row_col(row, col);
 
             let doc = alloc.stack(vec![
-                alloc.reflow(r"I am in the middle of a header, but I got stuck here:"),
+                alloc.reflow(r"I am partway through parsing a header, but I got stuck here:"),
                 alloc.region_with_subregion(surroundings, region),
                 alloc.concat(vec![
                     alloc.reflow("I am expecting the "),
@@ -2604,8 +2634,7 @@ fn to_exposes_report<'a>(
             let region = Region::from_row_col(row, col);
 
             let doc = alloc.stack(vec![
-                alloc
-                    .reflow(r"I am in the middle of parsing a exposes list, but I got stuck here:"),
+                alloc.reflow(r"I am partway through parsing a exposes list, but I got stuck here:"),
                 alloc.region_with_subregion(surroundings, region),
                 alloc.concat(vec![alloc.reflow(
                     "I was expecting a type name, value name or function name next, like ",
@@ -2627,7 +2656,7 @@ fn to_exposes_report<'a>(
             let region = Region::from_row_col(row, col);
 
             let doc = alloc.stack(vec![
-                alloc.reflow(r"I am in the middle of a header, but I got stuck here:"),
+                alloc.reflow(r"I am partway through parsing a header, but I got stuck here:"),
                 alloc.region_with_subregion(surroundings, region),
                 alloc.concat(vec![
                     alloc.reflow("I am expecting the "),
@@ -2667,8 +2696,7 @@ fn to_imports_report<'a>(
             let region = Region::from_row_col(row, col);
 
             let doc = alloc.stack(vec![
-                alloc
-                    .reflow(r"I am in the middle of parsing a imports list, but I got stuck here:"),
+                alloc.reflow(r"I am partway through parsing a imports list, but I got stuck here:"),
                 alloc.region_with_subregion(surroundings, region),
                 alloc.concat(vec![alloc.reflow(
                     "I was expecting a type name, value name or function name next, like ",
@@ -2690,7 +2718,7 @@ fn to_imports_report<'a>(
             let region = Region::from_row_col(row, col);
 
             let doc = alloc.stack(vec![
-                alloc.reflow(r"I am in the middle of a header, but I got stuck here:"),
+                alloc.reflow(r"I am partway through parsing a header, but I got stuck here:"),
                 alloc.region_with_subregion(surroundings, region),
                 alloc.concat(vec![
                     alloc.reflow("I am expecting the "),
@@ -2730,7 +2758,7 @@ fn to_requires_report<'a>(
             let region = Region::from_row_col(row, col);
 
             let doc = alloc.stack(vec![
-                alloc.reflow(r"I am in the middle of a header, but I got stuck here:"),
+                alloc.reflow(r"I am partway through parsing a header, but I got stuck here:"),
                 alloc.region_with_subregion(surroundings, region),
                 alloc.concat(vec![
                     alloc.reflow("I am expecting the "),
@@ -2755,6 +2783,82 @@ fn to_requires_report<'a>(
     }
 }
 
+fn to_packages_report<'a>(
+    alloc: &'a RocDocAllocator<'a>,
+    filename: PathBuf,
+    parse_problem: &roc_parse::parser::EPackages,
+    start_row: Row,
+    start_col: Col,
+) -> Report<'a> {
+    use roc_parse::parser::EPackages;
+
+    match *parse_problem {
+        EPackages::Packages(row, col) => {
+            let surroundings = Region::from_rows_cols(start_row, start_col, row, col);
+            let region = Region::from_row_col(row, col);
+
+            let doc = alloc.stack(vec![
+                alloc.reflow(r"I am partway through parsing a header, but I got stuck here:"),
+                alloc.region_with_subregion(surroundings, region),
+                alloc.concat(vec![
+                    alloc.reflow("I am expecting the "),
+                    alloc.keyword("packages"),
+                    alloc.reflow(" keyword next, like "),
+                ]),
+                alloc.parser_suggestion("packages {}").indent(4),
+            ]);
+
+            Report {
+                filename,
+                doc,
+                title: "MISSING PACKAGES".to_string(),
+            }
+        }
+
+        EPackages::Space(error, row, col) => to_space_report(alloc, filename, &error, row, col),
+
+        _ => todo!("unhandled parse error {:?}", parse_problem),
+    }
+}
+
+fn to_effects_report<'a>(
+    alloc: &'a RocDocAllocator<'a>,
+    filename: PathBuf,
+    parse_problem: &roc_parse::parser::EEffects,
+    start_row: Row,
+    start_col: Col,
+) -> Report<'a> {
+    use roc_parse::parser::EEffects;
+
+    match *parse_problem {
+        EEffects::Effects(row, col) => {
+            let surroundings = Region::from_rows_cols(start_row, start_col, row, col);
+            let region = Region::from_row_col(row, col);
+
+            let doc = alloc.stack(vec![
+                alloc.reflow(r"I am partway through parsing a header, but I got stuck here:"),
+                alloc.region_with_subregion(surroundings, region),
+                alloc.concat(vec![
+                    alloc.reflow("I am expecting the "),
+                    alloc.keyword("effects"),
+                    alloc.reflow(" keyword next, like "),
+                ]),
+                alloc.parser_suggestion("effects {}").indent(4),
+            ]);
+
+            Report {
+                filename,
+                doc,
+                title: "MISSING PACKAGES".to_string(),
+            }
+        }
+
+        EEffects::Space(error, row, col) => to_space_report(alloc, filename, &error, row, col),
+
+        _ => todo!("unhandled parse error {:?}", parse_problem),
+    }
+}
+
 fn to_space_report<'a>(
     alloc: &'a RocDocAllocator<'a>,
     filename: PathBuf,
diff --git a/compiler/reporting/tests/test_reporting.rs b/compiler/reporting/tests/test_reporting.rs
index d24ff00022..84befac1a5 100644
--- a/compiler/reporting/tests/test_reporting.rs
+++ b/compiler/reporting/tests/test_reporting.rs
@@ -5839,4 +5839,30 @@ mod test_reporting {
             ),
         )
     }
+
+    #[test]
+    fn invalid_app_name() {
+        report_header_problem_as(
+            indoc!(
+                r#"
+                app foobar 
+                    exposes [ main, @Foo ]
+                    imports [base.Task, Base64 ]
+                "#
+            ),
+            indoc!(
+                r#"
+                ── WEIRD APP NAME ──────────────────────────────────────────────────────────────
+                
+                I am partway through parsing a header, but got stuck here:
+                
+                1│  app foobar 
+                        ^
+                
+                I am expecting an application name next, like app "main" or
+                app "editor". App names are surrounded by quotation marks.
+            "#
+            ),
+        )
+    }
 }

From 25d7caa89e5e4c7e252f627a417414f41c2afcfe Mon Sep 17 00:00:00 2001
From: Folkert <folkert@folkertdev.nl>
Date: Tue, 9 Mar 2021 22:00:00 +0100
Subject: [PATCH 24/74] port platform module

---
 compiler/parse/src/module.rs          | 30 ++++++++++++++++++++-------
 compiler/parse/src/parser.rs          |  1 +
 compiler/reporting/src/error/parse.rs | 21 +++++++++++++++++++
 3 files changed, 44 insertions(+), 8 deletions(-)

diff --git a/compiler/parse/src/module.rs b/compiler/parse/src/module.rs
index 7b25e80def..be55df9694 100644
--- a/compiler/parse/src/module.rs
+++ b/compiler/parse/src/module.rs
@@ -208,25 +208,39 @@ fn app_header_help<'a>() -> impl Parser<'a, AppHeader<'a>, EHeader<'a>> {
 
 #[inline(always)]
 fn platform_header<'a>() -> impl Parser<'a, PlatformHeader<'a>, SyntaxError<'a>> {
+    specialize(|e, _, _| SyntaxError::Header(e), platform_header_help())
+}
+
+#[inline(always)]
+fn platform_header_help<'a>() -> impl Parser<'a, PlatformHeader<'a>, EHeader<'a>> {
     |arena, state| {
-        let (_, after_platform_keyword, state) = space1(1).parse(arena, state)?;
-        let (_, name, state) = loc!(package_name()).parse(arena, state)?;
+        let min_indent = 1;
+
+        let (_, after_platform_keyword, state) =
+            space0_e(min_indent, EHeader::Space, EHeader::IndentStart).parse(arena, state)?;
+        let (_, name, state) = loc!(specialize(
+            |_, r, c| EHeader::PlatformName(r, c),
+            package_name()
+        ))
+        .parse(arena, state)?;
 
         let (_, ((before_requires, after_requires), requires), state) =
-            requires().parse(arena, state)?;
+            specialize(EHeader::Requires, requires_help()).parse(arena, state)?;
 
         let (_, ((before_exposes, after_exposes), exposes), state) =
-            exposes_modules().parse(arena, state)?;
+            specialize(EHeader::Exposes, exposes_modules_help()).parse(arena, state)?;
 
-        let (_, packages, state) = packages().parse(arena, state)?;
+        let (_, packages, state) =
+            specialize(EHeader::Packages, packages_help()).parse(arena, state)?;
 
         let (_, ((before_imports, after_imports), imports), state) =
-            imports().parse(arena, state)?;
+            specialize(EHeader::Imports, imports_help()).parse(arena, state)?;
 
         let (_, ((before_provides, after_provides), provides), state) =
-            provides_without_to().parse(arena, state)?;
+            specialize(EHeader::Provides, provides_without_to_help()).parse(arena, state)?;
 
-        let (_, effects, state) = effects().parse(arena, state)?;
+        let (_, effects, state) =
+            specialize(EHeader::Effects, effects_help()).parse(arena, state)?;
 
         let header = PlatformHeader {
             name,
diff --git a/compiler/parse/src/parser.rs b/compiler/parse/src/parser.rs
index 786454ac73..6848480b55 100644
--- a/compiler/parse/src/parser.rs
+++ b/compiler/parse/src/parser.rs
@@ -350,6 +350,7 @@ pub enum EHeader<'a> {
     Space(BadInputError, Row, Col),
     ModuleName(Row, Col),
     AppName(EString<'a>, Row, Col),
+    PlatformName(Row, Col),
     IndentStart(Row, Col),
 }
 
diff --git a/compiler/reporting/src/error/parse.rs b/compiler/reporting/src/error/parse.rs
index f5d9ea662e..d3886c27ed 100644
--- a/compiler/reporting/src/error/parse.rs
+++ b/compiler/reporting/src/error/parse.rs
@@ -2552,6 +2552,27 @@ fn to_header_report<'a>(
             }
         }
 
+        EHeader::PlatformName(row, col) => {
+            let surroundings = Region::from_rows_cols(start_row, start_col, *row, *col);
+            let region = Region::from_row_col(*row, *col);
+
+            let doc = alloc.stack(vec![
+                alloc.reflow(r"I am partway through parsing a header, but got stuck here:"),
+                alloc.region_with_subregion(surroundings, region),
+                alloc.concat(vec![
+                    alloc.reflow("I am expecting a platform name next, like "),
+                    alloc.parser_suggestion("roc/core"),
+                    alloc.reflow("."),
+                ]),
+            ]);
+
+            Report {
+                filename,
+                doc,
+                title: "WEIRD MODULE NAME".to_string(),
+            }
+        }
+
         EHeader::Space(error, row, col) => to_space_report(alloc, filename, &error, *row, *col),
     }
 }

From d6ff5540dca30467c0fedbd32507933d0e6ffda3 Mon Sep 17 00:00:00 2001
From: Folkert <folkert@folkertdev.nl>
Date: Tue, 9 Mar 2021 22:02:34 +0100
Subject: [PATCH 25/74] cleanup

---
 compiler/parse/src/module.rs | 175 ++++-------------------------------
 1 file changed, 20 insertions(+), 155 deletions(-)

diff --git a/compiler/parse/src/module.rs b/compiler/parse/src/module.rs
index be55df9694..f5bb27afb8 100644
--- a/compiler/parse/src/module.rs
+++ b/compiler/parse/src/module.rs
@@ -1,5 +1,5 @@
 use crate::ast::{Attempting, CommentOrNewline, Def, Module};
-use crate::blankspace::{space0, space0_around, space0_before, space0_before_e, space0_e, space1};
+use crate::blankspace::{space0_around, space0_before_e, space0_e};
 use crate::expr::def;
 use crate::header::{
     package_entry, package_name, package_or_path, AppHeader, Effects, ExposesEntry, ImportsEntry,
@@ -8,9 +8,9 @@ use crate::header::{
 use crate::ident::{lowercase_ident, unqualified_ident, uppercase_ident};
 use crate::parser::Progress::{self, *};
 use crate::parser::{
-    ascii_char, ascii_string, backtrackable, end_of_file, loc, peek_utf8_char, peek_utf8_char_at,
-    specialize, unexpected, word1, Col, EEffects, EExposes, EHeader, EImports, EPackages,
-    EProvides, ERequires, ETypedIdent, Parser, Row, State, SyntaxError,
+    ascii_string, backtrackable, end_of_file, loc, peek_utf8_char, peek_utf8_char_at, specialize,
+    unexpected, word1, Col, EEffects, EExposes, EHeader, EImports, EPackages, EProvides, ERequires,
+    ETypedIdent, Parser, Row, State, SyntaxError,
 };
 use crate::string_literal;
 use crate::type_annotation;
@@ -51,7 +51,7 @@ fn interface_header_help<'a>() -> impl Parser<'a, InterfaceHeader<'a>, EHeader<'
         let (_, ((before_exposes, after_exposes), exposes), state) =
             specialize(EHeader::Exposes, exposes_values()).parse(arena, state)?;
         let (_, ((before_imports, after_imports), imports), state) =
-            specialize(EHeader::Imports, imports_help()).parse(arena, state)?;
+            specialize(EHeader::Imports, imports()).parse(arena, state)?;
 
         let header = InterfaceHeader {
             name,
@@ -155,9 +155,9 @@ fn app_header_help<'a>() -> impl Parser<'a, AppHeader<'a>, EHeader<'a>> {
         .parse(arena, state)?;
 
         let (_, opt_pkgs, state) =
-            maybe!(specialize(EHeader::Packages, packages_help())).parse(arena, state)?;
+            maybe!(specialize(EHeader::Packages, packages())).parse(arena, state)?;
         let (_, opt_imports, state) =
-            maybe!(specialize(EHeader::Imports, imports_help())).parse(arena, state)?;
+            maybe!(specialize(EHeader::Imports, imports())).parse(arena, state)?;
         let (_, provides, state) =
             specialize(EHeader::Provides, provides_to()).parse(arena, state)?;
 
@@ -225,22 +225,20 @@ fn platform_header_help<'a>() -> impl Parser<'a, PlatformHeader<'a>, EHeader<'a>
         .parse(arena, state)?;
 
         let (_, ((before_requires, after_requires), requires), state) =
-            specialize(EHeader::Requires, requires_help()).parse(arena, state)?;
+            specialize(EHeader::Requires, requires()).parse(arena, state)?;
 
         let (_, ((before_exposes, after_exposes), exposes), state) =
-            specialize(EHeader::Exposes, exposes_modules_help()).parse(arena, state)?;
+            specialize(EHeader::Exposes, exposes_modules()).parse(arena, state)?;
 
-        let (_, packages, state) =
-            specialize(EHeader::Packages, packages_help()).parse(arena, state)?;
+        let (_, packages, state) = specialize(EHeader::Packages, packages()).parse(arena, state)?;
 
         let (_, ((before_imports, after_imports), imports), state) =
-            specialize(EHeader::Imports, imports_help()).parse(arena, state)?;
+            specialize(EHeader::Imports, imports()).parse(arena, state)?;
 
         let (_, ((before_provides, after_provides), provides), state) =
-            specialize(EHeader::Provides, provides_without_to_help()).parse(arena, state)?;
+            specialize(EHeader::Provides, provides_without_to()).parse(arena, state)?;
 
-        let (_, effects, state) =
-            specialize(EHeader::Effects, effects_help()).parse(arena, state)?;
+        let (_, effects, state) = specialize(EHeader::Effects, effects()).parse(arena, state)?;
 
         let header = PlatformHeader {
             name,
@@ -296,7 +294,7 @@ fn provides_to<'a>() -> impl Parser<'a, ProvidesTo<'a>, EProvides> {
 
     map!(
         and!(
-            provides_without_to_help(),
+            provides_without_to(),
             and!(
                 spaces_around_keyword(
                     min_indent,
@@ -330,21 +328,6 @@ fn provides_to<'a>() -> impl Parser<'a, ProvidesTo<'a>, EProvides> {
 
 #[inline(always)]
 fn provides_without_to<'a>() -> impl Parser<
-    'a,
-    (
-        (&'a [CommentOrNewline<'a>], &'a [CommentOrNewline<'a>]),
-        Vec<'a, Located<ExposesEntry<'a, &'a str>>>,
-    ),
-    SyntaxError<'a>,
-> {
-    specialize(
-        |e, r, c| SyntaxError::Header(EHeader::Provides(e, r, c)),
-        provides_without_to_help(),
-    )
-}
-
-#[inline(always)]
-fn provides_without_to_help<'a>() -> impl Parser<
     'a,
     (
         (&'a [CommentOrNewline<'a>], &'a [CommentOrNewline<'a>]),
@@ -390,21 +373,6 @@ where
 
 #[inline(always)]
 fn requires<'a>() -> impl Parser<
-    'a,
-    (
-        (&'a [CommentOrNewline<'a>], &'a [CommentOrNewline<'a>]),
-        Vec<'a, Located<TypedIdent<'a>>>,
-    ),
-    SyntaxError<'a>,
-> {
-    specialize(
-        |e, r, c| SyntaxError::Header(EHeader::Requires(e, r, c)),
-        requires_help(),
-    )
-}
-
-#[inline(always)]
-fn requires_help<'a>() -> impl Parser<
     'a,
     (
         (&'a [CommentOrNewline<'a>], &'a [CommentOrNewline<'a>]),
@@ -424,7 +392,7 @@ fn requires_help<'a>() -> impl Parser<
         ),
         collection_e!(
             word1(b'{', ERequires::ListStart),
-            specialize(ERequires::TypedIdent, loc!(typed_ident_help())),
+            specialize(ERequires::TypedIdent, loc!(typed_ident())),
             word1(b',', ERequires::ListEnd),
             word1(b'}', ERequires::ListEnd),
             min_indent,
@@ -466,21 +434,6 @@ fn exposes_values<'a>() -> impl Parser<
     )
 }
 
-#[inline(always)]
-fn exposes_modules<'a>() -> impl Parser<
-    'a,
-    (
-        (&'a [CommentOrNewline<'a>], &'a [CommentOrNewline<'a>]),
-        Vec<'a, Located<ExposesEntry<'a, ModuleName<'a>>>>,
-    ),
-    SyntaxError<'a>,
-> {
-    specialize(
-        |e, r, c| SyntaxError::Header(EHeader::Exposes(e, r, c)),
-        exposes_modules_help(),
-    )
-}
-
 fn spaces_around_keyword<'a, E>(
     min_indent: u16,
     keyword: &'static str,
@@ -502,7 +455,7 @@ where
 }
 
 #[inline(always)]
-fn exposes_modules_help<'a>() -> impl Parser<
+fn exposes_modules<'a>() -> impl Parser<
     'a,
     (
         (&'a [CommentOrNewline<'a>], &'a [CommentOrNewline<'a>]),
@@ -555,44 +508,8 @@ struct Packages<'a> {
     after_packages_keyword: &'a [CommentOrNewline<'a>],
 }
 
-/*
 #[inline(always)]
-fn packages<'a>() -> impl Parser<'a, Packages<'a>, SyntaxError<'a>> {
-    map!(
-        and!(
-            and!(
-                skip_second!(backtrackable(space1(1)), ascii_string("packages")),
-                space1(1)
-            ),
-            collection!(
-                ascii_char(b'{'),
-                loc!(package_entry()),
-                ascii_char(b','),
-                ascii_char(b'}'),
-                1
-            )
-        ),
-        |((before_packages_keyword, after_packages_keyword), entries)| {
-            Packages {
-                entries,
-                before_packages_keyword,
-                after_packages_keyword,
-            }
-        }
-    )
-}
-*/
-
-#[inline(always)]
-fn packages<'a>() -> impl Parser<'a, Packages<'a>, SyntaxError<'a>> {
-    specialize(
-        |e, r, c| SyntaxError::Header(EHeader::Packages(e, r, c)),
-        packages_help(),
-    )
-}
-
-#[inline(always)]
-fn packages_help<'a>() -> impl Parser<'a, Packages<'a>, EPackages> {
+fn packages<'a>() -> impl Parser<'a, Packages<'a>, EPackages> {
     let min_indent = 1;
 
     map!(
@@ -630,21 +547,6 @@ fn packages_help<'a>() -> impl Parser<'a, Packages<'a>, EPackages> {
 
 #[inline(always)]
 fn imports<'a>() -> impl Parser<
-    'a,
-    (
-        (&'a [CommentOrNewline<'a>], &'a [CommentOrNewline<'a>]),
-        Vec<'a, Located<ImportsEntry<'a>>>,
-    ),
-    SyntaxError<'a>,
-> {
-    specialize(
-        |e, r, c| SyntaxError::Header(EHeader::Imports(e, r, c)),
-        imports_help(),
-    )
-}
-
-#[inline(always)]
-fn imports_help<'a>() -> impl Parser<
     'a,
     (
         (&'a [CommentOrNewline<'a>], &'a [CommentOrNewline<'a>]),
@@ -676,15 +578,7 @@ fn imports_help<'a>() -> impl Parser<
 }
 
 #[inline(always)]
-fn effects<'a>() -> impl Parser<'a, Effects<'a>, SyntaxError<'a>> {
-    specialize(
-        |e, r, c| SyntaxError::Header(EHeader::Effects(e, r, c)),
-        effects_help(),
-    )
-}
-
-#[inline(always)]
-fn effects_help<'a>() -> impl Parser<'a, Effects<'a>, EEffects<'a>> {
+fn effects<'a>() -> impl Parser<'a, Effects<'a>, EEffects<'a>> {
     move |arena, state| {
         let min_indent = 1;
 
@@ -714,7 +608,7 @@ fn effects_help<'a>() -> impl Parser<'a, Effects<'a>, EEffects<'a>> {
         .parse(arena, state)?;
         let (_, entries, state) = collection_e!(
             word1(b'{', EEffects::ListStart),
-            specialize(EEffects::TypedIdent, loc!(typed_ident_help())),
+            specialize(EEffects::TypedIdent, loc!(typed_ident())),
             word1(b',', EEffects::ListEnd),
             word1(b'}', EEffects::ListEnd),
             min_indent,
@@ -739,36 +633,7 @@ fn effects_help<'a>() -> impl Parser<'a, Effects<'a>, EEffects<'a>> {
 }
 
 #[inline(always)]
-fn typed_ident<'a>() -> impl Parser<'a, TypedIdent<'a>, SyntaxError<'a>> {
-    move |arena, state| {
-        // You must have a field name, e.g. "email"
-        let (_, ident, state) = loc!(lowercase_ident()).parse(arena, state)?;
-
-        let (_, spaces_before_colon, state) = space0(0).parse(arena, state)?;
-
-        let (_, ann, state) = skip_first!(
-            ascii_char(b':'),
-            space0_before(type_annotation::located(0), 0)
-        )
-        .parse(arena, state)?;
-
-        // e.g.
-        //
-        // printLine : Str -> Effect {}
-
-        Ok((
-            MadeProgress,
-            TypedIdent::Entry {
-                ident,
-                spaces_before_colon,
-                ann,
-            },
-            state,
-        ))
-    }
-}
-
-fn typed_ident_help<'a>() -> impl Parser<'a, TypedIdent<'a>, ETypedIdent<'a>> {
+fn typed_ident<'a>() -> impl Parser<'a, TypedIdent<'a>, ETypedIdent<'a>> {
     // e.g.
     //
     // printLine : Str -> Effect {}

From 932dcf6da7542b8bbbc2bfb37381f72a29cb5708 Mon Sep 17 00:00:00 2001
From: Folkert <folkert@folkertdev.nl>
Date: Tue, 9 Mar 2021 22:34:10 +0100
Subject: [PATCH 26/74] faster module name parsing

---
 compiler/parse/src/module.rs | 139 +++++++++++++++++------------------
 compiler/parse/src/parser.rs |   1 +
 2 files changed, 70 insertions(+), 70 deletions(-)

diff --git a/compiler/parse/src/module.rs b/compiler/parse/src/module.rs
index f5bb27afb8..3083c01ad7 100644
--- a/compiler/parse/src/module.rs
+++ b/compiler/parse/src/module.rs
@@ -1,4 +1,4 @@
-use crate::ast::{Attempting, CommentOrNewline, Def, Module};
+use crate::ast::{CommentOrNewline, Def, Module};
 use crate::blankspace::{space0_around, space0_before_e, space0_e};
 use crate::expr::def;
 use crate::header::{
@@ -8,27 +8,38 @@ use crate::header::{
 use crate::ident::{lowercase_ident, unqualified_ident, uppercase_ident};
 use crate::parser::Progress::{self, *};
 use crate::parser::{
-    ascii_string, backtrackable, end_of_file, loc, peek_utf8_char, peek_utf8_char_at, specialize,
-    unexpected, word1, Col, EEffects, EExposes, EHeader, EImports, EPackages, EProvides, ERequires,
-    ETypedIdent, Parser, Row, State, SyntaxError,
+    backtrackable, end_of_file, loc, specialize, word1, Col, EEffects, EExposes, EHeader, EImports,
+    EPackages, EProvides, ERequires, ETypedIdent, Parser, Row, State, SyntaxError,
 };
 use crate::string_literal;
 use crate::type_annotation;
-use bumpalo::collections::{String, Vec};
+use bumpalo::collections::Vec;
 use roc_region::all::Located;
 
 pub fn header<'a>() -> impl Parser<'a, Module<'a>, SyntaxError<'a>> {
+    specialize(|e, _, _| SyntaxError::Header(e), header_help())
+}
+
+fn header_help<'a>() -> impl Parser<'a, Module<'a>, EHeader<'a>> {
+    use crate::parser::keyword_e;
+
     one_of![
         map!(
-            skip_first!(debug!(ascii_string("app")), app_header()),
+            skip_first!(keyword_e("app", EHeader::Start), app_header_help()),
             |header| { Module::App { header } }
         ),
         map!(
-            skip_first!(ascii_string("platform"), platform_header()),
+            skip_first!(
+                keyword_e("platform", EHeader::Start),
+                platform_header_help()
+            ),
             |header| { Module::Platform { header } }
         ),
         map!(
-            skip_first!(debug!(ascii_string("interface")), interface_header()),
+            skip_first!(
+                keyword_e("interface", EHeader::Start),
+                interface_header_help()
+            ),
             |header| { Module::Interface { header } }
         )
     ]
@@ -68,72 +79,60 @@ fn interface_header_help<'a>() -> impl Parser<'a, InterfaceHeader<'a>, EHeader<'
     }
 }
 
-#[inline(always)]
-pub fn module_name<'a>() -> impl Parser<'a, ModuleName<'a>, SyntaxError<'a>> {
-    move |arena, mut state: State<'a>| {
-        match peek_utf8_char(&state) {
-            Ok((first_letter, bytes_parsed)) => {
-                if !first_letter.is_uppercase() {
-                    return Err(unexpected(0, Attempting::Module, state));
-                };
+fn chomp_module_name<'a>(buffer: &'a [u8]) -> Result<&'a str, Progress> {
+    use encode_unicode::CharExt;
 
-                let mut buf = String::with_capacity_in(4, arena);
+    let mut chomped = 0;
 
-                buf.push(first_letter);
-
-                state = state.advance_without_indenting(bytes_parsed)?;
-
-                while !state.bytes.is_empty() {
-                    match peek_utf8_char(&state) {
-                        Ok((ch, bytes_parsed)) => {
-                            // After the first character, only these are allowed:
-                            //
-                            // * Unicode alphabetic chars - you might include `鹏` if that's clear to your readers
-                            // * ASCII digits - e.g. `1` but not `¾`, both of which pass .is_numeric()
-                            // * A '.' separating module parts
-                            if ch.is_alphabetic() || ch.is_ascii_digit() {
-                                state = state.advance_without_indenting(bytes_parsed)?;
-
-                                buf.push(ch);
-                            } else if ch == '.' {
-                                match peek_utf8_char_at(&state, 1) {
-                                    Ok((next, next_bytes_parsed)) => {
-                                        if next.is_uppercase() {
-                                            // If we hit another uppercase letter, keep going!
-                                            buf.push('.');
-                                            buf.push(next);
-
-                                            state = state.advance_without_indenting(
-                                                bytes_parsed + next_bytes_parsed,
-                                            )?;
-                                        } else {
-                                            // We have finished parsing the module name.
-                                            //
-                                            // There may be an identifier after this '.',
-                                            // e.g. "baz" in `Foo.Bar.baz`
-                                            return Ok((
-                                                MadeProgress,
-                                                ModuleName::new(buf.into_bump_str()),
-                                                state,
-                                            ));
-                                        }
-                                    }
-                                    Err(reason) => return state.fail(arena, MadeProgress, reason),
-                                }
-                            } else {
-                                // This is the end of the module name. We're done!
-                                break;
-                            }
-                        }
-                        Err(reason) => return state.fail(arena, MadeProgress, reason),
-                    }
-                }
-
-                Ok((MadeProgress, ModuleName::new(buf.into_bump_str()), state))
-            }
-            Err(reason) => state.fail(arena, MadeProgress, reason),
+    if let Ok((first_letter, width)) = char::from_utf8_slice_start(&buffer[chomped..]) {
+        if first_letter.is_uppercase() {
+            chomped += width;
+        } else {
+            return Err(Progress::NoProgress);
         }
     }
+
+    while let Ok((ch, width)) = char::from_utf8_slice_start(&buffer[chomped..]) {
+        // After the first character, only these are allowed:
+        //
+        // * Unicode alphabetic chars - you might include `鹏` if that's clear to your readers
+        // * ASCII digits - e.g. `1` but not `¾`, both of which pass .is_numeric()
+        // * A '.' separating module parts
+        if ch.is_alphabetic() || ch.is_ascii_digit() {
+            chomped += width;
+        } else if ch == '.' {
+            chomped += width;
+
+            if let Ok((first_letter, width)) = char::from_utf8_slice_start(&buffer[chomped..]) {
+                if first_letter.is_uppercase() {
+                    chomped += width;
+                } else {
+                    return Err(Progress::MadeProgress);
+                }
+            }
+        } else {
+            // we're done
+            break;
+        }
+    }
+
+    let name = unsafe { std::str::from_utf8_unchecked(&buffer[..chomped]) };
+
+    Ok(name)
+}
+
+#[inline(always)]
+fn module_name<'a>() -> impl Parser<'a, ModuleName<'a>, ()> {
+    |_, mut state: State<'a>| match chomp_module_name(state.bytes) {
+        Ok(name) => {
+            let width = name.len();
+            state.column += width as u16;
+            state.bytes = &state.bytes[width..];
+
+            Ok((MadeProgress, ModuleName::new(name), state))
+        }
+        Err(progress) => Err((progress, (), state)),
+    }
 }
 
 #[inline(always)]
diff --git a/compiler/parse/src/parser.rs b/compiler/parse/src/parser.rs
index 6848480b55..de6bbd2ee1 100644
--- a/compiler/parse/src/parser.rs
+++ b/compiler/parse/src/parser.rs
@@ -348,6 +348,7 @@ pub enum EHeader<'a> {
     Effects(EEffects<'a>, Row, Col),
 
     Space(BadInputError, Row, Col),
+    Start(Row, Col),
     ModuleName(Row, Col),
     AppName(EString<'a>, Row, Col),
     PlatformName(Row, Col),

From 86ef187d1cd2e9cb4afd8deda8b80fcaf2de3031 Mon Sep 17 00:00:00 2001
From: Folkert <folkert@folkertdev.nl>
Date: Tue, 9 Mar 2021 22:39:32 +0100
Subject: [PATCH 27/74] cleanup

---
 compiler/parse/src/module.rs          | 33 ++++-----------------
 compiler/reporting/src/error/parse.rs | 42 ++++++++++++++++++++++++++-
 2 files changed, 47 insertions(+), 28 deletions(-)

diff --git a/compiler/parse/src/module.rs b/compiler/parse/src/module.rs
index 3083c01ad7..7c270bcd67 100644
--- a/compiler/parse/src/module.rs
+++ b/compiler/parse/src/module.rs
@@ -25,33 +25,22 @@ fn header_help<'a>() -> impl Parser<'a, Module<'a>, EHeader<'a>> {
 
     one_of![
         map!(
-            skip_first!(keyword_e("app", EHeader::Start), app_header_help()),
+            skip_first!(keyword_e("app", EHeader::Start), app_header()),
             |header| { Module::App { header } }
         ),
         map!(
-            skip_first!(
-                keyword_e("platform", EHeader::Start),
-                platform_header_help()
-            ),
+            skip_first!(keyword_e("platform", EHeader::Start), platform_header()),
             |header| { Module::Platform { header } }
         ),
         map!(
-            skip_first!(
-                keyword_e("interface", EHeader::Start),
-                interface_header_help()
-            ),
+            skip_first!(keyword_e("interface", EHeader::Start), interface_header()),
             |header| { Module::Interface { header } }
         )
     ]
 }
 
 #[inline(always)]
-fn interface_header<'a>() -> impl Parser<'a, InterfaceHeader<'a>, SyntaxError<'a>> {
-    specialize(|e, _, _| SyntaxError::Header(e), interface_header_help())
-}
-
-#[inline(always)]
-fn interface_header_help<'a>() -> impl Parser<'a, InterfaceHeader<'a>, EHeader<'a>> {
+fn interface_header<'a>() -> impl Parser<'a, InterfaceHeader<'a>, EHeader<'a>> {
     |arena, state| {
         let min_indent = 1;
 
@@ -136,12 +125,7 @@ fn module_name<'a>() -> impl Parser<'a, ModuleName<'a>, ()> {
 }
 
 #[inline(always)]
-fn app_header<'a>() -> impl Parser<'a, AppHeader<'a>, SyntaxError<'a>> {
-    specialize(|e, _, _| SyntaxError::Header(e), app_header_help())
-}
-
-#[inline(always)]
-fn app_header_help<'a>() -> impl Parser<'a, AppHeader<'a>, EHeader<'a>> {
+fn app_header<'a>() -> impl Parser<'a, AppHeader<'a>, EHeader<'a>> {
     |arena, state| {
         let min_indent = 1;
 
@@ -206,12 +190,7 @@ fn app_header_help<'a>() -> impl Parser<'a, AppHeader<'a>, EHeader<'a>> {
 }
 
 #[inline(always)]
-fn platform_header<'a>() -> impl Parser<'a, PlatformHeader<'a>, SyntaxError<'a>> {
-    specialize(|e, _, _| SyntaxError::Header(e), platform_header_help())
-}
-
-#[inline(always)]
-fn platform_header_help<'a>() -> impl Parser<'a, PlatformHeader<'a>, EHeader<'a>> {
+fn platform_header<'a>() -> impl Parser<'a, PlatformHeader<'a>, EHeader<'a>> {
     |arena, state| {
         let min_indent = 1;
 
diff --git a/compiler/reporting/src/error/parse.rs b/compiler/reporting/src/error/parse.rs
index d3886c27ed..d485467733 100644
--- a/compiler/reporting/src/error/parse.rs
+++ b/compiler/reporting/src/error/parse.rs
@@ -2504,7 +2504,47 @@ fn to_header_report<'a>(
             to_effects_report(alloc, filename, &effects, *row, *col)
         }
 
-        EHeader::IndentStart(row, col) => todo!(),
+        EHeader::IndentStart(row, col) => {
+            let surroundings = Region::from_rows_cols(start_row, start_col, *row, *col);
+            let region = Region::from_row_col(*row, *col);
+
+            let doc = alloc.stack(vec![
+                alloc.reflow(r"I am partway through parsing a header, but got stuck here:"),
+                alloc.region_with_subregion(surroundings, region),
+                alloc.concat(vec![alloc.reflow("I may be confused by indentation.")]),
+            ]);
+
+            Report {
+                filename,
+                doc,
+                title: "INCOMPLETE HEADER".to_string(),
+            }
+        }
+
+        EHeader::Start(row, col) => {
+            let surroundings = Region::from_rows_cols(start_row, start_col, *row, *col);
+            let region = Region::from_row_col(*row, *col);
+
+            let doc = alloc.stack(vec![
+                alloc.reflow(r"I am expecting a header, but got stuck here:"),
+                alloc.region_with_subregion(surroundings, region),
+                alloc.concat(vec![
+                    alloc.reflow("I am expecting a module keyword next, one of "),
+                    alloc.keyword("interface"),
+                    alloc.reflow(", "),
+                    alloc.keyword("app"),
+                    alloc.reflow(" or "),
+                    alloc.keyword("platform"),
+                    alloc.reflow("."),
+                ]),
+            ]);
+
+            Report {
+                filename,
+                doc,
+                title: "MISSING HEADER".to_string(),
+            }
+        }
 
         EHeader::ModuleName(row, col) => {
             let surroundings = Region::from_rows_cols(start_row, start_col, *row, *col);

From bd61a03ae045cc4b502bea912460ec5265bc1a8f Mon Sep 17 00:00:00 2001
From: Folkert <folkert@folkertdev.nl>
Date: Tue, 9 Mar 2021 23:06:17 +0100
Subject: [PATCH 28/74] port headers!

---
 compiler/parse/src/module.rs          |  8 ++++++--
 compiler/reporting/src/error/parse.rs | 23 +++++++++++++++++++++++
 2 files changed, 29 insertions(+), 2 deletions(-)

diff --git a/compiler/parse/src/module.rs b/compiler/parse/src/module.rs
index 7c270bcd67..5e7a8e5535 100644
--- a/compiler/parse/src/module.rs
+++ b/compiler/parse/src/module.rs
@@ -8,7 +8,7 @@ use crate::header::{
 use crate::ident::{lowercase_ident, unqualified_ident, uppercase_ident};
 use crate::parser::Progress::{self, *};
 use crate::parser::{
-    backtrackable, end_of_file, loc, specialize, word1, Col, EEffects, EExposes, EHeader, EImports,
+    backtrackable, end_of_file, specialize, word1, Col, EEffects, EExposes, EHeader, EImports,
     EPackages, EProvides, ERequires, ETypedIdent, Parser, Row, State, SyntaxError,
 };
 use crate::string_literal;
@@ -95,6 +95,10 @@ fn chomp_module_name<'a>(buffer: &'a [u8]) -> Result<&'a str, Progress> {
             if let Ok((first_letter, width)) = char::from_utf8_slice_start(&buffer[chomped..]) {
                 if first_letter.is_uppercase() {
                     chomped += width;
+                } else if first_letter == '{' {
+                    // the .{ starting a `Foo.{ bar, baz }` importing clauses
+                    chomped -= width;
+                    break;
                 } else {
                     return Err(Progress::MadeProgress);
                 }
@@ -246,7 +250,7 @@ fn platform_header<'a>() -> impl Parser<'a, PlatformHeader<'a>, EHeader<'a>> {
 #[inline(always)]
 pub fn module_defs<'a>() -> impl Parser<'a, Vec<'a, Located<Def<'a>>>, SyntaxError<'a>> {
     // force that we pare until the end of the input
-    skip_second!(zero_or_more!(space0_around(loc(def(0)), 0)), end_of_file())
+    skip_second!(zero_or_more!(space0_around(loc!(def(0)), 0)), end_of_file())
 }
 #[derive(Debug)]
 struct ProvidesTo<'a> {
diff --git a/compiler/reporting/src/error/parse.rs b/compiler/reporting/src/error/parse.rs
index d485467733..cfa73606b7 100644
--- a/compiler/reporting/src/error/parse.rs
+++ b/compiler/reporting/src/error/parse.rs
@@ -2800,6 +2800,29 @@ fn to_imports_report<'a>(
 
         EImports::Space(error, row, col) => to_space_report(alloc, filename, &error, row, col),
 
+        EImports::ModuleName(row, col) => {
+            let surroundings = Region::from_rows_cols(start_row, start_col, row, col);
+            let region = Region::from_row_col(row, col);
+
+            let doc = alloc.stack(vec![
+                alloc.reflow(r"I am partway through parsing a header, but got stuck here:"),
+                alloc.region_with_subregion(surroundings, region),
+                alloc.concat(vec![
+                    alloc.reflow("I am expecting a module name next, like "),
+                    alloc.parser_suggestion("BigNum"),
+                    alloc.reflow(" or "),
+                    alloc.parser_suggestion("Main"),
+                    alloc.reflow(". Module names must start with an uppercase letter."),
+                ]),
+            ]);
+
+            Report {
+                filename,
+                doc,
+                title: "WEIRD MODULE NAME".to_string(),
+            }
+        }
+
         _ => todo!("unhandled parse error {:?}", parse_problem),
     }
 }

From 91271d0308e0b88f573adcacf8bb4c64f7d48ffc Mon Sep 17 00:00:00 2001
From: Folkert <folkert@folkertdev.nl>
Date: Tue, 9 Mar 2021 23:20:31 +0100
Subject: [PATCH 29/74] don't leak implementation details

---
 compiler/load/src/file.rs          | 24 ++++++++---------
 compiler/parse/src/module.rs       | 12 ++++++---
 compiler/parse/src/test_helpers.rs | 14 +---------
 compiler/parse/tests/test_parse.rs | 41 +++++++++++++-----------------
 editor/src/lang/roc_file.rs        |  6 ++---
 5 files changed, 42 insertions(+), 55 deletions(-)

diff --git a/compiler/load/src/file.rs b/compiler/load/src/file.rs
index 7ae0aa7833..a92d075677 100644
--- a/compiler/load/src/file.rs
+++ b/compiler/load/src/file.rs
@@ -2305,7 +2305,7 @@ fn load_pkg_config<'a>(
             let parse_start = SystemTime::now();
             let bytes = arena.alloc(bytes_vec);
             let parse_state = parser::State::new_in(arena, bytes);
-            let parsed = roc_parse::module::header().parse(&arena, parse_state);
+            let parsed = roc_parse::module::parse_header(&arena, parse_state);
             let parse_header_duration = parse_start.elapsed().unwrap();
 
             // Insert the first entries for this module's timings
@@ -2319,19 +2319,19 @@ fn load_pkg_config<'a>(
             effect_module_timing.parse_header = parse_header_duration;
 
             match parsed {
-                Ok((_, ast::Module::Interface { header }, _parse_state)) => {
+                Ok((ast::Module::Interface { header }, _parse_state)) => {
                     Err(LoadingProblem::UnexpectedHeader(format!(
                         "expected platform/package module, got Interface with header\n{:?}",
                         header
                     )))
                 }
-                Ok((_, ast::Module::App { header }, _parse_state)) => {
+                Ok((ast::Module::App { header }, _parse_state)) => {
                     Err(LoadingProblem::UnexpectedHeader(format!(
                         "expected platform/package module, got App with header\n{:?}",
                         header
                     )))
                 }
-                Ok((_, ast::Module::Platform { header }, parser_state)) => {
+                Ok((ast::Module::Platform { header }, parser_state)) => {
                     // make a Pkg-Config module that ultimately exposes `main` to the host
                     let pkg_config_module_msg = fabricate_pkg_config_module(
                         arena,
@@ -2359,8 +2359,8 @@ fn load_pkg_config<'a>(
 
                     Ok(Msg::Many(vec![effects_module_msg, pkg_config_module_msg]))
                 }
-                Err((_, fail, _)) => Err(LoadingProblem::ParsingFailed(
-                    fail.into_parse_problem(filename, bytes),
+                Err(fail) => Err(LoadingProblem::ParsingFailed(
+                    SyntaxError::Header(fail).into_parse_problem(filename, bytes),
                 )),
             }
         }
@@ -2475,7 +2475,7 @@ fn parse_header<'a>(
 ) -> Result<(ModuleId, Msg<'a>), LoadingProblem<'a>> {
     let parse_start = SystemTime::now();
     let parse_state = parser::State::new_in(arena, src_bytes);
-    let parsed = roc_parse::module::header().parse(&arena, parse_state);
+    let parsed = roc_parse::module::parse_header(&arena, parse_state);
     let parse_header_duration = parse_start.elapsed().unwrap();
 
     // Insert the first entries for this module's timings
@@ -2485,7 +2485,7 @@ fn parse_header<'a>(
     module_timing.parse_header = parse_header_duration;
 
     match parsed {
-        Ok((_, ast::Module::Interface { header }, parse_state)) => {
+        Ok((ast::Module::Interface { header }, parse_state)) => {
             let header_src = unsafe {
                 let chomped = src_bytes.len() - parse_state.bytes.len();
                 std::str::from_utf8_unchecked(&src_bytes[..chomped])
@@ -2514,7 +2514,7 @@ fn parse_header<'a>(
                 module_timing,
             ))
         }
-        Ok((_, ast::Module::App { header }, parse_state)) => {
+        Ok((ast::Module::App { header }, parse_state)) => {
             let mut pkg_config_dir = filename.clone();
             pkg_config_dir.pop();
 
@@ -2623,7 +2623,7 @@ fn parse_header<'a>(
                 },
             }
         }
-        Ok((_, ast::Module::Platform { header }, _parse_state)) => Ok(fabricate_effects_module(
+        Ok((ast::Module::Platform { header }, _parse_state)) => Ok(fabricate_effects_module(
             arena,
             &"",
             module_ids,
@@ -2632,8 +2632,8 @@ fn parse_header<'a>(
             header,
             module_timing,
         )),
-        Err((_, fail, _)) => Err(LoadingProblem::ParsingFailed(
-            fail.into_parse_problem(filename, src_bytes),
+        Err(fail) => Err(LoadingProblem::ParsingFailed(
+            SyntaxError::Header(fail).into_parse_problem(filename, src_bytes),
         )),
     }
 }
diff --git a/compiler/parse/src/module.rs b/compiler/parse/src/module.rs
index 5e7a8e5535..fab4c3ab4d 100644
--- a/compiler/parse/src/module.rs
+++ b/compiler/parse/src/module.rs
@@ -16,11 +16,17 @@ use crate::type_annotation;
 use bumpalo::collections::Vec;
 use roc_region::all::Located;
 
-pub fn header<'a>() -> impl Parser<'a, Module<'a>, SyntaxError<'a>> {
-    specialize(|e, _, _| SyntaxError::Header(e), header_help())
+pub fn parse_header<'a>(
+    arena: &'a bumpalo::Bump,
+    state: State<'a>,
+) -> Result<(Module<'a>, State<'a>), EHeader<'a>> {
+    match header().parse(arena, state) {
+        Ok((_, module, state)) => Ok((module, state)),
+        Err((_, fail, _)) => Err(fail),
+    }
 }
 
-fn header_help<'a>() -> impl Parser<'a, Module<'a>, EHeader<'a>> {
+fn header<'a>() -> impl Parser<'a, Module<'a>, EHeader<'a>> {
     use crate::parser::keyword_e;
 
     one_of![
diff --git a/compiler/parse/src/test_helpers.rs b/compiler/parse/src/test_helpers.rs
index 7cfddd8d8c..7fce100612 100644
--- a/compiler/parse/src/test_helpers.rs
+++ b/compiler/parse/src/test_helpers.rs
@@ -1,7 +1,7 @@
 use crate::ast;
 use crate::blankspace::space0_before;
 use crate::expr::expr;
-use crate::module::{header, module_defs};
+use crate::module::module_defs;
 use crate::parser::{loc, Parser, State, SyntaxError};
 use bumpalo::collections::Vec;
 use bumpalo::Bump;
@@ -14,18 +14,6 @@ pub fn parse_expr_with<'a>(
     parse_loc_with(arena, input).map(|loc_expr| loc_expr.value)
 }
 
-pub fn parse_header_with<'a>(
-    arena: &'a Bump,
-    input: &'a str,
-) -> Result<ast::Module<'a>, SyntaxError<'a>> {
-    let state = State::new_in(arena, input.trim().as_bytes());
-    let answer = header().parse(arena, state);
-
-    answer
-        .map(|(_, loc_expr, _)| loc_expr)
-        .map_err(|(_, fail, _)| fail)
-}
-
 #[allow(dead_code)]
 pub fn parse_defs_with<'a>(
     arena: &'a Bump,
diff --git a/compiler/parse/tests/test_parse.rs b/compiler/parse/tests/test_parse.rs
index 084f169f12..58dfb65174 100644
--- a/compiler/parse/tests/test_parse.rs
+++ b/compiler/parse/tests/test_parse.rs
@@ -2433,9 +2433,8 @@ mod test_parse {
                 app "test-app" packages {} imports [] provides [] to blah
             "#
         );
-        let actual = roc_parse::module::header()
-            .parse(&arena, State::new_in(&arena, src.as_bytes()))
-            .map(|tuple| tuple.1);
+        let actual = roc_parse::module::parse_header(&arena, State::new_in(&arena, src.as_bytes()))
+            .map(|tuple| tuple.0);
 
         assert_eq!(Ok(expected), actual);
     }
@@ -2474,9 +2473,8 @@ mod test_parse {
             "#
         );
 
-        let actual = roc_parse::module::header()
-            .parse(&arena, State::new_in(&arena, src.as_bytes()))
-            .map(|tuple| tuple.1);
+        let actual = roc_parse::module::parse_header(&arena, State::new_in(&arena, src.as_bytes()))
+            .map(|tuple| tuple.0);
 
         assert_eq!(Ok(expected), actual);
     }
@@ -2530,9 +2528,8 @@ mod test_parse {
             "#
         );
 
-        let actual = roc_parse::module::header()
-            .parse(&arena, State::new_in(&arena, src.as_bytes()))
-            .map(|tuple| tuple.1);
+        let actual = roc_parse::module::parse_header(&arena, State::new_in(&arena, src.as_bytes()))
+            .map(|tuple| tuple.0);
 
         assert_eq!(Ok(expected), actual);
     }
@@ -2576,9 +2573,8 @@ mod test_parse {
         let expected = roc_parse::ast::Module::Platform { header };
 
         let src = "platform rtfeldman/blah requires {} exposes [] packages {} imports [] provides [] effects fx.Blah {}";
-        let actual = roc_parse::module::header()
-            .parse(&arena, State::new_in(&arena, src.as_bytes()))
-            .map(|tuple| tuple.1);
+        let actual = roc_parse::module::parse_header(&arena, State::new_in(&arena, src.as_bytes()))
+            .map(|tuple| tuple.0);
 
         assert_eq!(Ok(expected), actual);
     }
@@ -2646,9 +2642,8 @@ mod test_parse {
                     effects fx.Effect {}
             "#
         );
-        let actual = roc_parse::module::header()
-            .parse(&arena, State::new_in(&arena, src.as_bytes()))
-            .map(|tuple| tuple.1);
+        let actual = roc_parse::module::parse_header(&arena, State::new_in(&arena, src.as_bytes()))
+            .map(|tuple| tuple.0);
 
         assert_eq!(Ok(expected), actual);
     }
@@ -2678,9 +2673,8 @@ mod test_parse {
                 interface Foo exposes [] imports []
             "#
         );
-        let actual = roc_parse::module::header()
-            .parse(&arena, State::new_in(&arena, src.as_bytes()))
-            .map(|tuple| tuple.1);
+        let actual = roc_parse::module::parse_header(&arena, State::new_in(&arena, src.as_bytes()))
+            .map(|tuple| tuple.0);
 
         assert_eq!(Ok(expected), actual);
     }
@@ -2710,9 +2704,8 @@ mod test_parse {
                 interface Foo.Bar.Baz exposes [] imports []
             "#
         );
-        let actual = roc_parse::module::header()
-            .parse(&arena, State::new_in(&arena, src.as_bytes()))
-            .map(|tuple| tuple.1);
+        let actual = roc_parse::module::parse_header(&arena, State::new_in(&arena, src.as_bytes()))
+            .map(|tuple| tuple.0);
 
         assert_eq!(Ok(expected), actual);
     }
@@ -2818,7 +2811,7 @@ mod test_parse {
 
         let actual = module_defs()
             .parse(&arena, State::new_in(&arena, src.as_bytes()))
-            .map(|tuple| tuple.1);
+            .map(|tuple| tuple.0);
 
         assert!(actual.is_ok());
     }
@@ -2840,7 +2833,7 @@ mod test_parse {
 
         let actual = module_defs()
             .parse(&arena, State::new_in(&arena, src.as_bytes()))
-            .map(|tuple| tuple.1);
+            .map(|tuple| tuple.0);
 
         assert!(actual.is_ok());
     }
@@ -2861,7 +2854,7 @@ mod test_parse {
 
         let actual = module_defs()
             .parse(&arena, State::new_in(&arena, src.as_bytes()))
-            .map(|tuple| tuple.1);
+            .map(|tuple| tuple.0);
 
         dbg!(&actual);
 
diff --git a/editor/src/lang/roc_file.rs b/editor/src/lang/roc_file.rs
index f034a1f1b0..f551d987e2 100644
--- a/editor/src/lang/roc_file.rs
+++ b/editor/src/lang/roc_file.rs
@@ -37,10 +37,10 @@ impl<'a> File<'a> {
         let allocation = arena.alloc(bytes);
 
         let module_parse_state = parser::State::new_in(arena, allocation);
-        let parsed_module = roc_parse::module::header().parse(&arena, module_parse_state);
+        let parsed_module = roc_parse::module::parse_header(&arena, module_parse_state);
 
         match parsed_module {
-            Ok((_, module, state)) => {
+            Ok((module, state)) => {
                 let parsed_defs = module_defs().parse(&arena, state);
 
                 match parsed_defs {
@@ -52,7 +52,7 @@ impl<'a> File<'a> {
                     Err((_, error, _)) => Err(ReadError::ParseDefs(error)),
                 }
             }
-            Err((_, error, _)) => Err(ReadError::ParseHeader(error)),
+            Err(error) => Err(ReadError::ParseHeader(SyntaxError::Header(error))),
         }
     }
 

From 4b8f5fb4777c9f8f89541fc9348aaddf57c3a1ad Mon Sep 17 00:00:00 2001
From: Folkert <folkert@folkertdev.nl>
Date: Wed, 10 Mar 2021 00:26:54 +0100
Subject: [PATCH 30/74] cleanup

---
 compiler/parse/src/header.rs | 95 +++++++++++++++++++-----------------
 1 file changed, 51 insertions(+), 44 deletions(-)

diff --git a/compiler/parse/src/header.rs b/compiler/parse/src/header.rs
index e289e15179..3bd83988ab 100644
--- a/compiler/parse/src/header.rs
+++ b/compiler/parse/src/header.rs
@@ -2,13 +2,10 @@ use crate::ast::{CommentOrNewline, Spaceable, StrLiteral, TypeAnnotation};
 use crate::blankspace::space0;
 use crate::ident::lowercase_ident;
 use crate::parser::{
-    ascii_char, optional, peek_utf8_char, specialize, unexpected_eof, Either, ParseResult, Parser,
-    Progress, Progress::*, State, SyntaxError,
+    ascii_char, optional, specialize, Either, Parser, Progress, Progress::*, State, SyntaxError,
 };
 use crate::string_literal;
-use bumpalo::collections::String;
 use bumpalo::collections::Vec;
-use bumpalo::Bump;
 use inlinable_string::InlinableString;
 use roc_region::all::Loc;
 
@@ -274,24 +271,22 @@ pub fn package_entry<'a>() -> impl Parser<'a, PackageEntry<'a>, SyntaxError<'a>>
 }
 
 pub fn package_or_path<'a>() -> impl Parser<'a, PackageOrPath<'a>, SyntaxError<'a>> {
-    map!(
-        either!(
+    one_of![
+        map!(
             specialize(
                 |e, r, c| SyntaxError::Expr(crate::parser::EExpr::Str(e, r, c)),
                 string_literal::parse()
             ),
+            PackageOrPath::Path
+        ),
+        map!(
             and!(
                 package_name(),
                 skip_first!(one_or_more!(ascii_char(b' ')), package_version())
-            )
-        ),
-        |answer| {
-            match answer {
-                Either::First(str_literal) => PackageOrPath::Path(str_literal),
-                Either::Second((name, version)) => PackageOrPath::Package(name, version),
-            }
-        }
-    )
+            ),
+            |(name, version)| { PackageOrPath::Package(name, version) }
+        )
+    ]
 }
 
 fn package_version<'a>() -> impl Parser<'a, Version<'a>, SyntaxError<'a>> {
@@ -300,45 +295,57 @@ fn package_version<'a>() -> impl Parser<'a, Version<'a>, SyntaxError<'a>> {
 
 #[inline(always)]
 pub fn package_name<'a>() -> impl Parser<'a, PackageName<'a>, SyntaxError<'a>> {
+    use encode_unicode::CharExt;
     // e.g. rtfeldman/blah
     //
     // Package names and accounts can be capitalized and can contain dashes.
     // They cannot contain underscores or other special characters.
     // They must be ASCII.
 
-    map!(
-        and!(
-            parse_package_part,
-            skip_first!(ascii_char(b'/'), parse_package_part)
-        ),
-        |(account, pkg)| { PackageName { account, pkg } }
-    )
-}
+    |_, mut state: State<'a>| match chomp_package_part(state.bytes) {
+        Err(progress) => Err((progress, SyntaxError::ConditionFailed, state)),
+        Ok(account) => {
+            let mut chomped = account.len();
+            if let Ok(('/', width)) = char::from_utf8_slice_start(&state.bytes[chomped..]) {
+                chomped += width;
+                match chomp_package_part(&state.bytes[chomped..]) {
+                    Err(progress) => Err((progress, SyntaxError::ConditionFailed, state)),
+                    Ok(pkg) => {
+                        chomped += pkg.len();
 
-fn parse_package_part<'a>(
-    arena: &'a Bump,
-    mut state: State<'a>,
-) -> ParseResult<'a, &'a str, SyntaxError<'a>> {
-    let mut part_buf = String::new_in(arena); // The current "part" (parts are dot-separated.)
+                        state.column += chomped as u16;
+                        state.bytes = &state.bytes[chomped..];
 
-    while !state.bytes.is_empty() {
-        match peek_utf8_char(&state) {
-            Ok((ch, bytes_parsed)) => {
-                if ch == '-' || ch.is_ascii_alphanumeric() {
-                    part_buf.push(ch);
-
-                    state = state.advance_without_indenting(bytes_parsed)?;
-                } else {
-                    let progress = Progress::progress_when(!part_buf.is_empty());
-                    return Ok((progress, part_buf.into_bump_str(), state));
+                        let value = PackageName { account, pkg };
+                        Ok((MadeProgress, value, state))
+                    }
                 }
-            }
-            Err(reason) => {
-                let progress = Progress::progress_when(!part_buf.is_empty());
-                return state.fail(arena, progress, reason);
+            } else {
+                Err((MadeProgress, SyntaxError::ConditionFailed, state))
             }
         }
     }
-
-    Err(unexpected_eof(arena, state, 0))
+}
+
+fn chomp_package_part<'a>(buffer: &'a [u8]) -> Result<&'a str, Progress> {
+    use encode_unicode::CharExt;
+
+    let mut chomped = 0;
+
+    while let Ok((ch, width)) = char::from_utf8_slice_start(&buffer[chomped..]) {
+        if ch == '-' || ch.is_ascii_alphanumeric() {
+            chomped += width;
+        } else {
+            // we're done
+            break;
+        }
+    }
+
+    if chomped == 0 {
+        Err(Progress::NoProgress)
+    } else {
+        let name = unsafe { std::str::from_utf8_unchecked(&buffer[..chomped]) };
+
+        Ok(name)
+    }
 }

From 2773639c7b28dd231ac20a8a84351cb88000fdab Mon Sep 17 00:00:00 2001
From: Folkert <folkert@folkertdev.nl>
Date: Wed, 10 Mar 2021 01:02:24 +0100
Subject: [PATCH 31/74] port header parsing

---
 compiler/parse/src/header.rs          | 88 +++++++++++++++++++++------
 compiler/parse/src/module.rs          | 32 ++++------
 compiler/parse/src/parser.rs          | 46 +++++++++-----
 compiler/reporting/src/error/parse.rs |  2 +-
 4 files changed, 113 insertions(+), 55 deletions(-)

diff --git a/compiler/parse/src/header.rs b/compiler/parse/src/header.rs
index 3bd83988ab..6b3d8d7089 100644
--- a/compiler/parse/src/header.rs
+++ b/compiler/parse/src/header.rs
@@ -1,8 +1,9 @@
 use crate::ast::{CommentOrNewline, Spaceable, StrLiteral, TypeAnnotation};
-use crate::blankspace::space0;
+use crate::blankspace::space0_e;
 use crate::ident::lowercase_ident;
+use crate::parser::Progress::{self, *};
 use crate::parser::{
-    ascii_char, optional, specialize, Either, Parser, Progress, Progress::*, State, SyntaxError,
+    specialize, word1, EPackageEntry, EPackageName, EPackageOrPath, Parser, State,
 };
 use crate::string_literal;
 use bumpalo::collections::Vec;
@@ -240,18 +241,32 @@ impl<'a> Spaceable<'a> for PackageEntry<'a> {
     }
 }
 
-pub fn package_entry<'a>() -> impl Parser<'a, PackageEntry<'a>, SyntaxError<'a>> {
+pub fn package_entry<'a>() -> impl Parser<'a, PackageEntry<'a>, EPackageEntry<'a>> {
     move |arena, state| {
         // You may optionally have a package shorthand,
         // e.g. "uc" in `uc: roc/unicode 1.0.0`
         //
         // (Indirect dependencies don't have a shorthand.)
-        let (_, opt_shorthand, state) = optional(and!(
-            skip_second!(lowercase_ident(), ascii_char(b':')),
-            space0(1)
+        let min_indent = 1;
+
+        let (_, opt_shorthand, state) = maybe!(and!(
+            skip_second!(
+                specialize(|_, r, c| EPackageEntry::Shorthand(r, c), lowercase_ident()),
+                word1(b':', EPackageEntry::Colon)
+            ),
+            space0_e(
+                min_indent,
+                EPackageEntry::Space,
+                EPackageEntry::IndentPackageOrPath
+            )
+        ))
+        .parse(arena, state)?;
+
+        let (_, package_or_path, state) = loc!(specialize(
+            EPackageEntry::BadPackageOrPath,
+            package_or_path()
         ))
         .parse(arena, state)?;
-        let (_, package_or_path, state) = loc!(package_or_path()).parse(arena, state)?;
 
         let entry = match opt_shorthand {
             Some((shorthand, spaces_after_shorthand)) => PackageEntry::Entry {
@@ -270,31 +285,54 @@ pub fn package_entry<'a>() -> impl Parser<'a, PackageEntry<'a>, SyntaxError<'a>>
     }
 }
 
-pub fn package_or_path<'a>() -> impl Parser<'a, PackageOrPath<'a>, SyntaxError<'a>> {
+pub fn package_or_path<'a>() -> impl Parser<'a, PackageOrPath<'a>, EPackageOrPath<'a>> {
     one_of![
         map!(
-            specialize(
-                |e, r, c| SyntaxError::Expr(crate::parser::EExpr::Str(e, r, c)),
-                string_literal::parse()
-            ),
+            specialize(EPackageOrPath::BadPath, string_literal::parse()),
             PackageOrPath::Path
         ),
         map!(
             and!(
-                package_name(),
-                skip_first!(one_or_more!(ascii_char(b' ')), package_version())
+                specialize(EPackageOrPath::BadPackage, package_name()),
+                skip_first!(skip_spaces(), package_version())
             ),
             |(name, version)| { PackageOrPath::Package(name, version) }
         )
     ]
 }
 
-fn package_version<'a>() -> impl Parser<'a, Version<'a>, SyntaxError<'a>> {
+fn skip_spaces<'a, T>() -> impl Parser<'a, (), T>
+where
+    T: 'a,
+{
+    |_, mut state: State<'a>| {
+        let mut chomped = 0;
+        let mut it = state.bytes.iter();
+
+        while let Some(b' ') = it.next() {
+            chomped += 1;
+        }
+
+        if chomped == 0 {
+            Ok((NoProgress, (), state))
+        } else {
+            state.column += chomped;
+            state.bytes = it.as_slice();
+
+            Ok((MadeProgress, (), state))
+        }
+    }
+}
+
+fn package_version<'a, T>() -> impl Parser<'a, Version<'a>, T>
+where
+    T: 'a,
+{
     move |_, _| todo!("TODO parse package version")
 }
 
 #[inline(always)]
-pub fn package_name<'a>() -> impl Parser<'a, PackageName<'a>, SyntaxError<'a>> {
+pub fn package_name<'a>() -> impl Parser<'a, PackageName<'a>, EPackageName> {
     use encode_unicode::CharExt;
     // e.g. rtfeldman/blah
     //
@@ -303,13 +341,21 @@ pub fn package_name<'a>() -> impl Parser<'a, PackageName<'a>, SyntaxError<'a>> {
     // They must be ASCII.
 
     |_, mut state: State<'a>| match chomp_package_part(state.bytes) {
-        Err(progress) => Err((progress, SyntaxError::ConditionFailed, state)),
+        Err(progress) => Err((
+            progress,
+            EPackageName::Account(state.line, state.column),
+            state,
+        )),
         Ok(account) => {
             let mut chomped = account.len();
             if let Ok(('/', width)) = char::from_utf8_slice_start(&state.bytes[chomped..]) {
                 chomped += width;
                 match chomp_package_part(&state.bytes[chomped..]) {
-                    Err(progress) => Err((progress, SyntaxError::ConditionFailed, state)),
+                    Err(progress) => Err((
+                        progress,
+                        EPackageName::Pkg(state.line, state.column + chomped as u16),
+                        state,
+                    )),
                     Ok(pkg) => {
                         chomped += pkg.len();
 
@@ -321,7 +367,11 @@ pub fn package_name<'a>() -> impl Parser<'a, PackageName<'a>, SyntaxError<'a>> {
                     }
                 }
             } else {
-                Err((MadeProgress, SyntaxError::ConditionFailed, state))
+                Err((
+                    MadeProgress,
+                    EPackageName::MissingSlash(state.line, state.column + chomped as u16),
+                    state,
+                ))
             }
         }
     }
diff --git a/compiler/parse/src/module.rs b/compiler/parse/src/module.rs
index fab4c3ab4d..710ce22bba 100644
--- a/compiler/parse/src/module.rs
+++ b/compiler/parse/src/module.rs
@@ -206,11 +206,8 @@ fn platform_header<'a>() -> impl Parser<'a, PlatformHeader<'a>, EHeader<'a>> {
 
         let (_, after_platform_keyword, state) =
             space0_e(min_indent, EHeader::Space, EHeader::IndentStart).parse(arena, state)?;
-        let (_, name, state) = loc!(specialize(
-            |_, r, c| EHeader::PlatformName(r, c),
-            package_name()
-        ))
-        .parse(arena, state)?;
+        let (_, name, state) =
+            loc!(specialize(EHeader::PlatformName, package_name())).parse(arena, state)?;
 
         let (_, ((before_requires, after_requires), requires), state) =
             specialize(EHeader::Requires, requires()).parse(arena, state)?;
@@ -269,15 +266,18 @@ struct ProvidesTo<'a> {
     after_to_keyword: &'a [CommentOrNewline<'a>],
 }
 
-fn provides_to_package<'a>() -> impl Parser<'a, To<'a>, SyntaxError<'a>> {
+fn provides_to_package<'a>() -> impl Parser<'a, To<'a>, EProvides<'a>> {
     one_of![
-        map!(lowercase_ident(), To::ExistingPackage),
-        map!(package_or_path(), To::NewPackage)
+        specialize(
+            |_, r, c| EProvides::Identifier(r, c),
+            map!(lowercase_ident(), To::ExistingPackage)
+        ),
+        specialize(EProvides::Package, map!(package_or_path(), To::NewPackage))
     ]
 }
 
 #[inline(always)]
-fn provides_to<'a>() -> impl Parser<'a, ProvidesTo<'a>, EProvides> {
+fn provides_to<'a>() -> impl Parser<'a, ProvidesTo<'a>, EProvides<'a>> {
     let min_indent = 1;
 
     map!(
@@ -292,10 +292,7 @@ fn provides_to<'a>() -> impl Parser<'a, ProvidesTo<'a>, EProvides> {
                     EProvides::IndentTo,
                     EProvides::IndentListStart
                 ),
-                loc!(specialize(
-                    |_, r, c| EProvides::Package(r, c),
-                    provides_to_package()
-                ))
+                loc!(provides_to_package())
             )
         ),
         |(
@@ -321,7 +318,7 @@ fn provides_without_to<'a>() -> impl Parser<
         (&'a [CommentOrNewline<'a>], &'a [CommentOrNewline<'a>]),
         Vec<'a, Located<ExposesEntry<'a, &'a str>>>,
     ),
-    EProvides,
+    EProvides<'a>,
 > {
     let min_indent = 1;
     and!(
@@ -497,7 +494,7 @@ struct Packages<'a> {
 }
 
 #[inline(always)]
-fn packages<'a>() -> impl Parser<'a, Packages<'a>, EPackages> {
+fn packages<'a>() -> impl Parser<'a, Packages<'a>, EPackages<'a>> {
     let min_indent = 1;
 
     map!(
@@ -512,10 +509,7 @@ fn packages<'a>() -> impl Parser<'a, Packages<'a>, EPackages> {
             ),
             collection_e!(
                 word1(b'{', EPackages::ListStart),
-                specialize(
-                    |_, r, c| EPackages::PackageEntry(r, c),
-                    loc!(package_entry())
-                ),
+                specialize(EPackages::PackageEntry, loc!(package_entry())),
                 word1(b',', EPackages::ListEnd),
                 word1(b'}', EPackages::ListEnd),
                 min_indent,
diff --git a/compiler/parse/src/parser.rs b/compiler/parse/src/parser.rs
index de6bbd2ee1..51cb45bc6e 100644
--- a/compiler/parse/src/parser.rs
+++ b/compiler/parse/src/parser.rs
@@ -340,23 +340,23 @@ pub enum SyntaxError<'a> {
 
 #[derive(Debug, Clone, PartialEq, Eq)]
 pub enum EHeader<'a> {
-    Provides(EProvides, Row, Col),
+    Provides(EProvides<'a>, Row, Col),
     Exposes(EExposes, Row, Col),
     Imports(EImports, Row, Col),
     Requires(ERequires<'a>, Row, Col),
-    Packages(EPackages, Row, Col),
+    Packages(EPackages<'a>, Row, Col),
     Effects(EEffects<'a>, Row, Col),
 
     Space(BadInputError, Row, Col),
     Start(Row, Col),
     ModuleName(Row, Col),
     AppName(EString<'a>, Row, Col),
-    PlatformName(Row, Col),
+    PlatformName(EPackageName, Row, Col),
     IndentStart(Row, Col),
 }
 
-#[derive(Debug, Clone, Copy, PartialEq, Eq)]
-pub enum EProvides {
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub enum EProvides<'a> {
     Provides(Row, Col),
     To(Row, Col),
     IndentProvides(Row, Col),
@@ -367,7 +367,7 @@ pub enum EProvides {
     ListStart(Row, Col),
     ListEnd(Row, Col),
     Identifier(Row, Col),
-    Package(Row, Col),
+    Package(EPackageOrPath<'a>, Row, Col),
     Space(BadInputError, Row, Col),
 }
 
@@ -407,7 +407,7 @@ pub enum ETypedIdent<'a> {
 }
 
 #[derive(Debug, Clone, PartialEq, Eq)]
-pub enum EPackages {
+pub enum EPackages<'a> {
     Space(BadInputError, Row, Col),
     Packages(Row, Col),
     IndentPackages(Row, Col),
@@ -415,7 +415,29 @@ pub enum EPackages {
     ListEnd(Row, Col),
     IndentListStart(Row, Col),
     IndentListEnd(Row, Col),
-    PackageEntry(Row, Col),
+    PackageEntry(EPackageEntry<'a>, Row, Col),
+}
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub enum EPackageName {
+    MissingSlash(Row, Col),
+    Account(Row, Col),
+    Pkg(Row, Col),
+}
+
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub enum EPackageOrPath<'a> {
+    BadPath(EString<'a>, Row, Col),
+    BadPackage(EPackageName, Row, Col),
+}
+
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub enum EPackageEntry<'a> {
+    BadPackageOrPath(EPackageOrPath<'a>, Row, Col),
+    Shorthand(Row, Col),
+    Colon(Row, Col),
+    IndentPackageOrPath(Row, Col),
+    Space(BadInputError, Row, Col),
 }
 
 #[derive(Debug, Clone, PartialEq, Eq)]
@@ -562,14 +584,6 @@ pub enum EString<'a> {
     Format(&'a SyntaxError<'a>, Row, Col),
 }
 
-// #[derive(Debug, Clone, Copy, PartialEq, Eq)]
-// pub enum Escape {
-//     EscapeUnknown,
-//     BadUnicodeFormat(u16),
-//     BadUnicodeCode(u16),
-//     BadUnicodeLength(u16, i32, i32),
-// }
-
 #[derive(Debug, Clone, PartialEq, Eq)]
 pub enum ERecord<'a> {
     End(Row, Col),
diff --git a/compiler/reporting/src/error/parse.rs b/compiler/reporting/src/error/parse.rs
index cfa73606b7..177707a186 100644
--- a/compiler/reporting/src/error/parse.rs
+++ b/compiler/reporting/src/error/parse.rs
@@ -2592,7 +2592,7 @@ fn to_header_report<'a>(
             }
         }
 
-        EHeader::PlatformName(row, col) => {
+        EHeader::PlatformName(_, row, col) => {
             let surroundings = Region::from_rows_cols(start_row, start_col, *row, *col);
             let region = Region::from_row_col(*row, *col);
 

From d2482246f2957168bba11fb4c2bc4ff348a9bd28 Mon Sep 17 00:00:00 2001
From: Folkert <folkert@folkertdev.nl>
Date: Wed, 10 Mar 2021 01:08:49 +0100
Subject: [PATCH 32/74] clippy

---
 compiler/parse/src/header.rs |  2 +-
 compiler/parse/src/module.rs | 13 +++++++------
 2 files changed, 8 insertions(+), 7 deletions(-)

diff --git a/compiler/parse/src/header.rs b/compiler/parse/src/header.rs
index 6b3d8d7089..5442509877 100644
--- a/compiler/parse/src/header.rs
+++ b/compiler/parse/src/header.rs
@@ -377,7 +377,7 @@ pub fn package_name<'a>() -> impl Parser<'a, PackageName<'a>, EPackageName> {
     }
 }
 
-fn chomp_package_part<'a>(buffer: &'a [u8]) -> Result<&'a str, Progress> {
+fn chomp_package_part(buffer: &[u8]) -> Result<&str, Progress> {
     use encode_unicode::CharExt;
 
     let mut chomped = 0;
diff --git a/compiler/parse/src/module.rs b/compiler/parse/src/module.rs
index 710ce22bba..32d2fb2919 100644
--- a/compiler/parse/src/module.rs
+++ b/compiler/parse/src/module.rs
@@ -74,7 +74,7 @@ fn interface_header<'a>() -> impl Parser<'a, InterfaceHeader<'a>, EHeader<'a>> {
     }
 }
 
-fn chomp_module_name<'a>(buffer: &'a [u8]) -> Result<&'a str, Progress> {
+fn chomp_module_name(buffer: &[u8]) -> Result<&str, Progress> {
     use encode_unicode::CharExt;
 
     let mut chomped = 0;
@@ -667,6 +667,11 @@ where
 fn imports_entry<'a>() -> impl Parser<'a, ImportsEntry<'a>, EImports> {
     let min_indent = 1;
 
+    type Temp<'a> = (
+        (Option<&'a str>, ModuleName<'a>),
+        Option<Vec<'a, Located<ExposesEntry<'a, &'a str>>>>,
+    );
+
     map_with_arena!(
         and!(
             and!(
@@ -692,11 +697,7 @@ fn imports_entry<'a>() -> impl Parser<'a, ImportsEntry<'a>, EImports> {
                 )
             ))
         ),
-        |arena,
-         ((opt_shortname, module_name), opt_values): (
-            (Option<&'a str>, ModuleName<'a>),
-            Option<Vec<'a, Located<ExposesEntry<'a, &'a str>>>>
-        )| {
+        |arena, ((opt_shortname, module_name), opt_values): Temp<'a>| {
             let exposed_values = opt_values.unwrap_or_else(|| Vec::new_in(arena));
 
             match opt_shortname {

From 181958f284ef20718b448ac0db253ca8f1b34882 Mon Sep 17 00:00:00 2001
From: rvcas <x@rvcas.dev>
Date: Tue, 9 Mar 2021 19:50:01 -0500
Subject: [PATCH 33/74] fix(List): i in list.zig needs to be reset

---
 compiler/builtins/bitcode/src/list.zig | 3 +++
 compiler/test_gen/src/gen_list.rs      | 4 ++--
 2 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/compiler/builtins/bitcode/src/list.zig b/compiler/builtins/bitcode/src/list.zig
index bd765e1eca..139163af1d 100644
--- a/compiler/builtins/bitcode/src/list.zig
+++ b/compiler/builtins/bitcode/src/list.zig
@@ -237,6 +237,7 @@ pub fn listMap3(list1: RocList, list2: RocList, list3: RocList, transform: Opaqu
                 // if the lists don't have equal length, we must consume the remaining elements
                 // In this case we consume by (recursively) decrementing the elements
                 if (list1.len() > output_length) {
+                    i = output_length;
                     while (i < list1.len()) : (i += 1) {
                         const element_a = source_a + i * a_width;
                         dec_a(element_a);
@@ -244,6 +245,7 @@ pub fn listMap3(list1: RocList, list2: RocList, list3: RocList, transform: Opaqu
                 }
 
                 if (list2.len() > output_length) {
+                    i = output_length;
                     while (i < list2.len()) : (i += 1) {
                         const element_b = source_b + i * b_width;
                         dec_b(element_b);
@@ -251,6 +253,7 @@ pub fn listMap3(list1: RocList, list2: RocList, list3: RocList, transform: Opaqu
                 }
 
                 if (list3.len() > output_length) {
+                    i = output_length;
                     while (i < list3.len()) : (i += 1) {
                         const element_c = source_c + i * c_width;
                         dec_c(element_c);
diff --git a/compiler/test_gen/src/gen_list.rs b/compiler/test_gen/src/gen_list.rs
index 83d93eebf2..047dcfae54 100644
--- a/compiler/test_gen/src/gen_list.rs
+++ b/compiler/test_gen/src/gen_list.rs
@@ -587,8 +587,8 @@ fn list_map3_different_length() {
         indoc!(
             r#"
             List.map3
-                ["a", "b", "d" ]
-                ["b"]
+                ["a", "b", "d"]
+                ["b", "x"]
                 ["c"]
                 (\a, b, c -> Str.concat a (Str.concat b c))
             "#

From 8ee99fa6be52543f610a221eaef2d412bc160cfd Mon Sep 17 00:00:00 2001
From: Folkert <folkert@folkertdev.nl>
Date: Wed, 10 Mar 2021 12:03:33 +0100
Subject: [PATCH 34/74] fix up tests

---
 compiler/can/tests/helpers/mod.rs          |  4 +--
 compiler/fmt/tests/test_fmt.rs             |  8 ++---
 compiler/reporting/tests/test_reporting.rs | 35 +++++++++++-----------
 3 files changed, 24 insertions(+), 23 deletions(-)

diff --git a/compiler/can/tests/helpers/mod.rs b/compiler/can/tests/helpers/mod.rs
index 679d341204..b1e2fb888e 100644
--- a/compiler/can/tests/helpers/mod.rs
+++ b/compiler/can/tests/helpers/mod.rs
@@ -8,7 +8,7 @@ use roc_can::operator;
 use roc_can::scope::Scope;
 use roc_collections::all::MutMap;
 use roc_module::symbol::{IdentIds, Interns, ModuleId, ModuleIds};
-use roc_parse::ast::{self, Attempting};
+use roc_parse::ast;
 use roc_parse::blankspace::space0_before;
 use roc_parse::parser::{loc, Parser, State, SyntaxError};
 use roc_problem::can::Problem;
@@ -30,7 +30,7 @@ pub fn parse_loc_with<'a>(
     arena: &'a Bump,
     input: &'a str,
 ) -> Result<Located<ast::Expr<'a>>, SyntaxError<'a>> {
-    let state = State::new_in(arena, input.trim().as_bytes(), Attempting::Module);
+    let state = State::new_in(arena, input.trim().as_bytes());
     let parser = space0_before(loc(roc_parse::expr::expr(0)), 0);
     let answer = parser.parse(&arena, state);
 
diff --git a/compiler/fmt/tests/test_fmt.rs b/compiler/fmt/tests/test_fmt.rs
index ee17739af7..d2faf53847 100644
--- a/compiler/fmt/tests/test_fmt.rs
+++ b/compiler/fmt/tests/test_fmt.rs
@@ -14,13 +14,13 @@ mod test_fmt {
     use roc_fmt::annotation::{Formattable, Newlines, Parens};
     use roc_fmt::def::fmt_def;
     use roc_fmt::module::fmt_module;
-    use roc_parse::ast::{Attempting, Expr};
+    use roc_parse::ast::Expr;
     use roc_parse::blankspace::space0_before;
     use roc_parse::module::{self, module_defs};
     use roc_parse::parser::{Parser, State, SyntaxError};
 
     fn parse_with<'a>(arena: &'a Bump, input: &'a str) -> Result<Expr<'a>, SyntaxError<'a>> {
-        let state = State::new_in(arena, input.trim().as_bytes(), Attempting::Module);
+        let state = State::new_in(arena, input.trim().as_bytes());
         let parser = space0_before(loc!(roc_parse::expr::expr(0)), 0);
         let answer = parser.parse(&arena, state);
 
@@ -55,8 +55,8 @@ mod test_fmt {
         let src = src.trim_end();
         let expected = expected.trim_end();
 
-        match module::header().parse(&arena, State::new_in(&arena, src.as_bytes(), Attempting::Module)) {
-            Ok((_, actual, state)) => {
+        match module::parse_header(&arena, State::new_in(&arena, src.as_bytes())) {
+            Ok((actual, state)) => {
                 let mut buf = String::new_in(&arena);
 
                 fmt_module(&mut buf, &actual);
diff --git a/compiler/reporting/tests/test_reporting.rs b/compiler/reporting/tests/test_reporting.rs
index 84befac1a5..dfd2bee8b8 100644
--- a/compiler/reporting/tests/test_reporting.rs
+++ b/compiler/reporting/tests/test_reporting.rs
@@ -182,15 +182,16 @@ mod test_reporting {
         let filename = filename_from_string(r"\code\proj\Main.roc");
         let src_lines: Vec<&str> = src.split('\n').collect();
 
-        use roc_parse::parser::Parser;
-        match roc_parse::module::header().parse(arena, state) {
-            Err((_, fail, _)) => {
+        match roc_parse::module::parse_header(arena, state) {
+            Err(fail) => {
                 let interns = Interns::default();
                 let home = crate::helpers::test_home();
 
                 let alloc = RocDocAllocator::new(&src_lines, home, &interns);
 
-                let problem = fail.into_parse_problem(filename.clone(), src.as_bytes());
+                use roc_parse::parser::SyntaxError;
+                let problem =
+                    SyntaxError::Header(fail).into_parse_problem(filename.clone(), src.as_bytes());
                 let doc = parse_problem(&alloc, filename, 0, problem);
 
                 callback(doc.pretty(&alloc).append(alloc.line()), buf)
@@ -3214,7 +3215,7 @@ mod test_reporting {
                 r#"
                 ── ARGUMENTS BEFORE EQUALS ─────────────────────────────────────────────────────
 
-                I am in the middle of parsing a definition, but I got stuck here:
+                I am partway through parsing a definition, but I got stuck here:
 
                 1│  f x y = x
                       ^^^
@@ -5037,13 +5038,13 @@ mod test_reporting {
             indoc!(
                 r#"
                 ── UNFINISHED ARGUMENT LIST ────────────────────────────────────────────────────
-
-                I am in the middle of parsing a function argument list, but I got
-                stuck at this comma:
-
+                
+                I am partway through parsing a function argument list, but I got stuck
+                at this comma:
+                
                 1│  \a,,b -> 1
                        ^
-
+                
                 I was expecting an argument pattern before this, so try adding an
                 argument before the comma and see if that helps?
             "#
@@ -5062,13 +5063,13 @@ mod test_reporting {
             indoc!(
                 r#"
                 ── UNFINISHED ARGUMENT LIST ────────────────────────────────────────────────────
-
-                I am in the middle of parsing a function argument list, but I got
-                stuck at this comma:
-
+                
+                I am partway through parsing a function argument list, but I got stuck
+                at this comma:
+                
                 1│  \,b -> 1
                      ^
-
+                
                 I was expecting an argument pattern before this, so try adding an
                 argument before the comma and see if that helps?
             "#
@@ -5772,7 +5773,7 @@ mod test_reporting {
                 r#"
                 ── WEIRD PROVIDES ──────────────────────────────────────────────────────────────
                 
-                I am in the middle of parsing a provides list, but I got stuck here:
+                I am partway through parsing a provides list, but I got stuck here:
                 
                 3│      imports [base.Task, Base64 ]
                 4│      provides [ main, @Foo ] to base
@@ -5800,7 +5801,7 @@ mod test_reporting {
                 r#"
                 ── WEIRD EXPOSES ───────────────────────────────────────────────────────────────
                 
-                I am in the middle of parsing a exposes list, but I got stuck here:
+                I am partway through parsing a exposes list, but I got stuck here:
                 
                 1│  interface Foobar 
                 2│      exposes [ main, @Foo ]

From 5e2848d10c99ee1b6b3330d48c7f9f386b16bbaf Mon Sep 17 00:00:00 2001
From: Folkert <folkert@folkertdev.nl>
Date: Wed, 10 Mar 2021 12:55:56 +0100
Subject: [PATCH 35/74] use the EExpr identifier parser

---
 compiler/parse/src/expr.rs    | 12 +++++------
 compiler/parse/src/ident.rs   | 39 ++++++++++++++++++++++++++++++++---
 compiler/parse/src/pattern.rs |  5 +++--
 3 files changed, 45 insertions(+), 11 deletions(-)

diff --git a/compiler/parse/src/expr.rs b/compiler/parse/src/expr.rs
index 5780967d54..1f69407eca 100644
--- a/compiler/parse/src/expr.rs
+++ b/compiler/parse/src/expr.rs
@@ -3,7 +3,7 @@ use crate::blankspace::{
     line_comment, space0_after_e, space0_around_ee, space0_before_e, space0_e, space1_e,
     spaces_exactly_e,
 };
-use crate::ident::{ident, lowercase_ident, Ident};
+use crate::ident::{lowercase_ident, parse_ident_help, Ident};
 use crate::keyword;
 use crate::parser::{
     self, allocated, and_then_with_indent_level, ascii_char, backtrackable, map, newline_char,
@@ -1967,11 +1967,11 @@ fn ident_then_args<'a>(
 }
 
 fn ident_without_apply_help<'a>() -> impl Parser<'a, Expr<'a>, EExpr<'a>> {
-    specialize_ref(
-        EExpr::Syntax,
-        then(loc!(ident()), move |arena, state, progress, loc_ident| {
+    then(
+        loc!(parse_ident_help),
+        move |arena, state, progress, loc_ident| {
             Ok((progress, ident_to_expr(arena, loc_ident.value), state))
-        }),
+        },
     )
 }
 
@@ -2163,7 +2163,7 @@ fn record_field_help<'a>(
 fn record_updateable_identifier<'a>() -> impl Parser<'a, Expr<'a>, ERecord<'a>> {
     specialize(
         |_, r, c| ERecord::Updateable(r, c),
-        map_with_arena!(ident(), ident_to_expr),
+        map_with_arena!(parse_ident_help, ident_to_expr),
     )
 }
 
diff --git a/compiler/parse/src/ident.rs b/compiler/parse/src/ident.rs
index bb3143b53d..d1819f7f36 100644
--- a/compiler/parse/src/ident.rs
+++ b/compiler/parse/src/ident.rs
@@ -61,11 +61,44 @@ impl<'a> Ident<'a> {
     }
 }
 
-pub fn ident<'a>() -> impl Parser<'a, Ident<'a>, SyntaxError<'a>> {
-    crate::parser::specialize(|e, _, _| SyntaxError::Expr(e), parse_ident_help)
+fn chomp_identifier<'a, F>(pred: F, buffer: &[u8]) -> Result<&str, Progress>
+where
+    F: Fn(char) -> bool,
+{
+    use encode_unicode::CharExt;
+
+    let mut chomped = 0;
+
+    match char::from_utf8_slice_start(&buffer[chomped..]) {
+        Ok((ch, width)) if pred(ch) => {
+            chomped += width;
+        }
+        _ => {
+            // no parse
+            return Err(Progress::NoProgress);
+        }
+    }
+
+    while let Ok((ch, width)) = char::from_utf8_slice_start(&buffer[chomped..]) {
+        // After the first character, only these are allowed:
+        //
+        // * Unicode alphabetic chars - you might include `鹏` if that's clear to your readers
+        // * ASCII digits - e.g. `1` but not `¾`, both of which pass .is_numeric()
+        // * A ':' indicating the end of the field
+        if ch.is_alphabetic() || ch.is_ascii_digit() {
+            chomped += width;
+        } else {
+            // we're done
+            break;
+        }
+    }
+
+    let name = unsafe { std::str::from_utf8_unchecked(&buffer[..chomped]) };
+
+    Ok(name)
 }
 
-pub fn global_tag_or_ident<'a, F>(pred: F) -> impl Parser<'a, &'a str, SyntaxError<'a>>
+fn global_tag_or_ident<'a, F>(pred: F) -> impl Parser<'a, &'a str, SyntaxError<'a>>
 where
     F: Fn(char) -> bool,
 {
diff --git a/compiler/parse/src/pattern.rs b/compiler/parse/src/pattern.rs
index 5e073623d8..146940d790 100644
--- a/compiler/parse/src/pattern.rs
+++ b/compiler/parse/src/pattern.rs
@@ -1,6 +1,6 @@
 use crate::ast::Pattern;
 use crate::blankspace::{space0_around_ee, space0_before_e, space0_e};
-use crate::ident::{ident, lowercase_ident, Ident};
+use crate::ident::{lowercase_ident, parse_ident_help, Ident};
 use crate::parser::Progress::{self, *};
 use crate::parser::{
     backtrackable, optional, specialize, specialize_ref, word1, EPattern, PInParens, PRecord,
@@ -179,7 +179,8 @@ fn loc_ident_pattern_help<'a>(
         let original_state = state.clone();
 
         let (_, loc_ident, state) =
-            specialize(|_, r, c| EPattern::Start(r, c), loc!(ident())).parse(arena, state)?;
+            specialize(|_, r, c| EPattern::Start(r, c), loc!(parse_ident_help))
+                .parse(arena, state)?;
 
         match loc_ident.value {
             Ident::GlobalTag(tag) => {

From 397e579d882e672026ca0052680f48e9b6df768e Mon Sep 17 00:00:00 2001
From: Folkert <folkert@folkertdev.nl>
Date: Wed, 10 Mar 2021 12:58:32 +0100
Subject: [PATCH 36/74] chomp from source string

---
 compiler/parse/src/ident.rs | 14 +++++++++++++-
 1 file changed, 13 insertions(+), 1 deletion(-)

diff --git a/compiler/parse/src/ident.rs b/compiler/parse/src/ident.rs
index d1819f7f36..59350b5897 100644
--- a/compiler/parse/src/ident.rs
+++ b/compiler/parse/src/ident.rs
@@ -316,6 +316,9 @@ pub fn parse_ident_help_help<'a>(
     let is_accessor_fn;
     let mut is_private_tag = false;
 
+    let bytes = state.bytes;
+    let mut chomped_capitalized = 0;
+
     // Identifiers and accessor functions must start with either a letter or a dot.
     // If this starts with neither, it must be something else!
     match peek_utf8_char(&state) {
@@ -420,6 +423,7 @@ pub fn parse_ident_help_help<'a>(
                     }
 
                     if is_capitalized {
+                        chomped_capitalized += part_buf.len() + (chomped_capitalized != 0) as usize;
                         capitalized_parts.push(part_buf.into_bump_str());
                     } else {
                         noncapitalized_parts.push(part_buf.into_bump_str());
@@ -478,6 +482,7 @@ pub fn parse_ident_help_help<'a>(
 
     // Record the final parts.
     if is_capitalized {
+        chomped_capitalized += part_buf.len() + (chomped_capitalized != 0) as usize;
         capitalized_parts.push(part_buf.into_bump_str());
     } else {
         noncapitalized_parts.push(part_buf.into_bump_str());
@@ -536,8 +541,15 @@ pub fn parse_ident_help_help<'a>(
         ));
     } else {
         // We have multiple noncapitalized parts, so this must be field access.
+        let module_name = if capitalized_parts.len() == 0 {
+            ""
+        } else {
+            let chomped = chomped_capitalized;
+            unsafe { std::str::from_utf8_unchecked(&bytes[..chomped]) }
+        };
+
         Ident::Access {
-            module_name: join_module_parts(arena, capitalized_parts.into_bump_slice()),
+            module_name,
             parts: noncapitalized_parts.into_bump_slice(),
         }
     };

From fd82f1d45b48d66f9e4ea66e2394649ba56a7c74 Mon Sep 17 00:00:00 2001
From: Folkert <folkert@folkertdev.nl>
Date: Wed, 10 Mar 2021 13:02:32 +0100
Subject: [PATCH 37/74] cparts

---
 compiler/parse/src/ident.rs | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/compiler/parse/src/ident.rs b/compiler/parse/src/ident.rs
index 59350b5897..3929260de8 100644
--- a/compiler/parse/src/ident.rs
+++ b/compiler/parse/src/ident.rs
@@ -318,6 +318,7 @@ pub fn parse_ident_help_help<'a>(
 
     let bytes = state.bytes;
     let mut chomped_capitalized = 0;
+    let mut cparts = 0;
 
     // Identifiers and accessor functions must start with either a letter or a dot.
     // If this starts with neither, it must be something else!
@@ -424,6 +425,7 @@ pub fn parse_ident_help_help<'a>(
 
                     if is_capitalized {
                         chomped_capitalized += part_buf.len() + (chomped_capitalized != 0) as usize;
+                        cparts += 1;
                         capitalized_parts.push(part_buf.into_bump_str());
                     } else {
                         noncapitalized_parts.push(part_buf.into_bump_str());
@@ -468,7 +470,7 @@ pub fn parse_ident_help_help<'a>(
         // If we made it this far and don't have a next_char, then necessarily
         // we have consumed a '.' char previously.
         let fail = if noncapitalized_parts.is_empty() {
-            if capitalized_parts.is_empty() {
+            if cparts == 0 {
                 BadIdent::StrayDot(state.line, state.column)
             } else {
                 BadIdent::WeirdDotQualified(state.line, state.column)
@@ -483,6 +485,7 @@ pub fn parse_ident_help_help<'a>(
     // Record the final parts.
     if is_capitalized {
         chomped_capitalized += part_buf.len() + (chomped_capitalized != 0) as usize;
+        cparts += 1;
         capitalized_parts.push(part_buf.into_bump_str());
     } else {
         noncapitalized_parts.push(part_buf.into_bump_str());
@@ -491,7 +494,7 @@ pub fn parse_ident_help_help<'a>(
     let answer = if is_accessor_fn {
         // Handle accessor functions first because they have the strictest requirements.
         // Accessor functions may have exactly 1 noncapitalized part, and no capitalzed parts.
-        if capitalized_parts.is_empty() && noncapitalized_parts.len() == 1 && !is_private_tag {
+        if cparts == 0 && noncapitalized_parts.len() == 1 && !is_private_tag {
             let value = noncapitalized_parts.iter().next().unwrap();
 
             Ident::AccessorFunction(value)
@@ -506,7 +509,7 @@ pub fn parse_ident_help_help<'a>(
         // We have capitalized parts only, so this must be a tag.
         match capitalized_parts.first() {
             Some(value) => {
-                if capitalized_parts.len() == 1 {
+                if cparts == 1 {
                     if is_private_tag {
                         Ident::PrivateTag(value)
                     } else {
@@ -541,7 +544,7 @@ pub fn parse_ident_help_help<'a>(
         ));
     } else {
         // We have multiple noncapitalized parts, so this must be field access.
-        let module_name = if capitalized_parts.len() == 0 {
+        let module_name = if cparts == 0 {
             ""
         } else {
             let chomped = chomped_capitalized;

From 058551a2246cff55bfcb1269b69c03473264cccd Mon Sep 17 00:00:00 2001
From: Folkert <folkert@folkertdev.nl>
Date: Wed, 10 Mar 2021 13:37:35 +0100
Subject: [PATCH 38/74] remove capitalized_parts

---
 compiler/parse/src/ident.rs | 40 ++++++++++++++++++-------------------
 1 file changed, 19 insertions(+), 21 deletions(-)

diff --git a/compiler/parse/src/ident.rs b/compiler/parse/src/ident.rs
index 3929260de8..2b9e943131 100644
--- a/compiler/parse/src/ident.rs
+++ b/compiler/parse/src/ident.rs
@@ -310,7 +310,6 @@ pub fn parse_ident_help_help<'a>(
     mut state: State<'a>,
 ) -> ParseResult<'a, (Ident<'a>, Option<char>), BadIdent> {
     let mut part_buf = String::new_in(arena); // The current "part" (parts are dot-separated.)
-    let mut capitalized_parts: Vec<&'a str> = Vec::new_in(arena);
     let mut noncapitalized_parts: Vec<&'a str> = Vec::new_in(arena);
     let mut is_capitalized;
     let is_accessor_fn;
@@ -426,7 +425,6 @@ pub fn parse_ident_help_help<'a>(
                     if is_capitalized {
                         chomped_capitalized += part_buf.len() + (chomped_capitalized != 0) as usize;
                         cparts += 1;
-                        capitalized_parts.push(part_buf.into_bump_str());
                     } else {
                         noncapitalized_parts.push(part_buf.into_bump_str());
                     }
@@ -486,7 +484,6 @@ pub fn parse_ident_help_help<'a>(
     if is_capitalized {
         chomped_capitalized += part_buf.len() + (chomped_capitalized != 0) as usize;
         cparts += 1;
-        capitalized_parts.push(part_buf.into_bump_str());
     } else {
         noncapitalized_parts.push(part_buf.into_bump_str());
     }
@@ -507,24 +504,8 @@ pub fn parse_ident_help_help<'a>(
         }
     } else if noncapitalized_parts.is_empty() {
         // We have capitalized parts only, so this must be a tag.
-        match capitalized_parts.first() {
-            Some(value) => {
-                if cparts == 1 {
-                    if is_private_tag {
-                        Ident::PrivateTag(value)
-                    } else {
-                        Ident::GlobalTag(value)
-                    }
-                } else {
-                    // This is a qualified tag, which is not allowed!
-                    return Err((
-                        MadeProgress,
-                        BadIdent::QualifiedTag(state.line, state.column),
-                        state,
-                    ));
-                }
-            }
-            None => {
+        match cparts {
+            0 => {
                 // We had neither capitalized nor noncapitalized parts,
                 // yet we made it this far. The only explanation is that this was
                 // a stray '.' drifting through the cosmos.
@@ -534,6 +515,23 @@ pub fn parse_ident_help_help<'a>(
                     state,
                 ));
             }
+            1 => {
+                let chomped = chomped_capitalized;
+                let value = unsafe { std::str::from_utf8_unchecked(&bytes[..chomped]) };
+                if is_private_tag {
+                    Ident::PrivateTag(value)
+                } else {
+                    Ident::GlobalTag(value)
+                }
+            }
+            _ => {
+                // This is a qualified tag, which is not allowed!
+                return Err((
+                    MadeProgress,
+                    BadIdent::QualifiedTag(state.line, state.column),
+                    state,
+                ));
+            }
         }
     } else if is_private_tag {
         // This is qualified field access with an '@' in front, which does not make sense!

From edd54ab4ab1a6d1e13b77f8af49811584e96fd40 Mon Sep 17 00:00:00 2001
From: Folkert <folkert@folkertdev.nl>
Date: Wed, 10 Mar 2021 15:23:11 +0100
Subject: [PATCH 39/74] specialize accessor parsing

---
 compiler/parse/src/ident.rs | 93 +++++++++++++++++++++++++++++++------
 1 file changed, 80 insertions(+), 13 deletions(-)

diff --git a/compiler/parse/src/ident.rs b/compiler/parse/src/ident.rs
index 2b9e943131..639fca2f3b 100644
--- a/compiler/parse/src/ident.rs
+++ b/compiler/parse/src/ident.rs
@@ -305,7 +305,44 @@ pub enum BadIdent {
 ///
 /// This is separate from the `ident` Parser because string interpolation
 /// wants to use it this way.
-pub fn parse_ident_help_help<'a>(
+
+/// a `.foo` accessor function
+fn chomp_accessor(buffer: &[u8], row: Row, col: Col) -> Result<&str, BadIdent> {
+    // assumes the leading `.` has been chomped already
+    use encode_unicode::CharExt;
+
+    let mut chomped = 0;
+
+    if let Ok((ch, width)) = char::from_utf8_slice_start(&buffer[chomped..]) {
+        if ch.is_lowercase() {
+            chomped += width;
+        } else {
+            return Err(BadIdent::StrayDot(row, col + 1));
+        }
+    }
+
+    while let Ok((ch, width)) = char::from_utf8_slice_start(&buffer[chomped..]) {
+        if ch.is_alphabetic() || ch.is_ascii_digit() {
+            chomped += width;
+        } else {
+            // we're done
+            break;
+        }
+    }
+
+    if chomped == 0 {
+        Err(BadIdent::StrayDot(row, col + 1))
+    } else if let Ok(('.', _)) = char::from_utf8_slice_start(&buffer[chomped..]) {
+        Err(BadIdent::WeirdAccessor(row, col))
+    } else {
+        let name = unsafe { std::str::from_utf8_unchecked(&buffer[..chomped]) };
+
+        dbg!(name);
+        Ok(name)
+    }
+}
+
+fn parse_ident_help_help<'a>(
     arena: &'a Bump,
     mut state: State<'a>,
 ) -> ParseResult<'a, (Ident<'a>, Option<char>), BadIdent> {
@@ -319,22 +356,36 @@ pub fn parse_ident_help_help<'a>(
     let mut chomped_capitalized = 0;
     let mut cparts = 0;
 
+    let mut chomped_part_buf = 0;
+    let mut chomped = 0;
+
     // Identifiers and accessor functions must start with either a letter or a dot.
     // If this starts with neither, it must be something else!
     match peek_utf8_char(&state) {
         Ok((first_ch, bytes_parsed)) => {
             if first_ch.is_alphabetic() {
                 part_buf.push(first_ch);
+                chomped_part_buf += bytes_parsed;
 
                 is_capitalized = first_ch.is_uppercase();
                 is_accessor_fn = false;
 
                 state = advance_state!(state, bytes_parsed)?;
             } else if first_ch == '.' {
-                is_capitalized = false;
-                is_accessor_fn = true;
+                match chomp_accessor(&state.bytes[1..], state.line, state.column) {
+                    Ok(accessor) => {
+                        let bytes_parsed = 1 + accessor.len();
 
-                state = advance_state!(state, bytes_parsed)?;
+                        state = advance_state!(state, bytes_parsed)?;
+
+                        return Ok((
+                            MadeProgress,
+                            (Ident::AccessorFunction(accessor), None),
+                            state,
+                        ));
+                    }
+                    Err(fail) => return Err((MadeProgress, fail, state)),
+                }
             } else if first_ch == '@' {
                 state = advance_state!(state, bytes_parsed)?;
 
@@ -346,6 +397,7 @@ pub fn parse_ident_help_help<'a>(
 
                             part_buf.push('@');
                             part_buf.push(next_ch);
+                            chomped_part_buf += 1 + next_bytes_parsed;
 
                             is_private_tag = true;
                             is_capitalized = true;
@@ -377,7 +429,7 @@ pub fn parse_ident_help_help<'a>(
 
     while !state.bytes.is_empty() {
         match peek_utf8_char(&state) {
-            Ok((ch, bytes_parsed)) => {
+            Ok((ch, width)) => {
                 // After the first character, only these are allowed:
                 //
                 // * Unicode alphabetic chars - you might name a variable `鹏` if that's clear to your readers
@@ -390,6 +442,7 @@ pub fn parse_ident_help_help<'a>(
                     }
 
                     part_buf.push(ch);
+                    chomped_part_buf += width;
                 } else if ch.is_ascii_digit() {
                     // Parts may not start with numbers!
                     if part_buf.is_empty() {
@@ -401,6 +454,7 @@ pub fn parse_ident_help_help<'a>(
                     }
 
                     part_buf.push(ch);
+                    chomped_part_buf += width;
                 } else if ch == '.' {
                     // There are two posssible errors here:
                     //
@@ -423,19 +477,27 @@ pub fn parse_ident_help_help<'a>(
                     }
 
                     if is_capitalized {
-                        chomped_capitalized += part_buf.len() + (chomped_capitalized != 0) as usize;
+                        chomped_capitalized +=
+                            chomped_part_buf + (chomped_capitalized != 0) as usize;
                         cparts += 1;
                     } else {
-                        noncapitalized_parts.push(part_buf.into_bump_str());
+                        let value = unsafe {
+                            std::str::from_utf8_unchecked(
+                                &bytes[chomped..chomped + chomped_part_buf],
+                            )
+                        };
+                        noncapitalized_parts.push(value);
                     }
 
                     // Now that we've recorded the contents of the current buffer, reset it.
                     part_buf = String::new_in(arena);
+                    chomped += chomped_part_buf + 1;
+                    chomped_part_buf = 0;
                 } else if ch == '_' {
                     // we don't allow underscores in the middle of an identifier
                     // but still parse them (and generate a malformed identifier)
                     // to give good error messages for this case
-                    state = advance_state!(state, bytes_parsed)?;
+                    state = advance_state!(state, width)?;
                     return Err((
                         MadeProgress,
                         BadIdent::Underscore(state.line, state.column),
@@ -447,7 +509,7 @@ pub fn parse_ident_help_help<'a>(
                     break;
                 }
 
-                state = advance_state!(state, bytes_parsed)?;
+                state = advance_state!(state, width)?;
             }
             Err(_reason) => {
                 //
@@ -460,7 +522,7 @@ pub fn parse_ident_help_help<'a>(
         }
     }
 
-    if part_buf.is_empty() {
+    if chomped_part_buf == 0 {
         // We probably had a trailing dot, e.g. `Foo.bar.` - this is malformed!
         //
         // This condition might also occur if we encounter a malformed accessor like `.|`
@@ -482,17 +544,22 @@ pub fn parse_ident_help_help<'a>(
 
     // Record the final parts.
     if is_capitalized {
-        chomped_capitalized += part_buf.len() + (chomped_capitalized != 0) as usize;
+        chomped_capitalized += chomped_part_buf + (chomped_capitalized != 0) as usize;
         cparts += 1;
     } else {
-        noncapitalized_parts.push(part_buf.into_bump_str());
+        let value =
+            unsafe { std::str::from_utf8_unchecked(&bytes[chomped..chomped + chomped_part_buf]) };
+        noncapitalized_parts.push(value);
     }
 
     let answer = if is_accessor_fn {
         // Handle accessor functions first because they have the strictest requirements.
         // Accessor functions may have exactly 1 noncapitalized part, and no capitalzed parts.
         if cparts == 0 && noncapitalized_parts.len() == 1 && !is_private_tag {
-            let value = noncapitalized_parts.iter().next().unwrap();
+            // an accessor starts with a `.`, but we drop that from the name
+            let value = unsafe {
+                std::str::from_utf8_unchecked(&bytes[1 + chomped..1 + chomped + chomped_part_buf])
+            };
 
             Ident::AccessorFunction(value)
         } else {

From ea32a3731550bb611e5096e21a934eb148b3fcfc Mon Sep 17 00:00:00 2001
From: Folkert <folkert@folkertdev.nl>
Date: Wed, 10 Mar 2021 17:26:42 +0100
Subject: [PATCH 40/74] improved private tag parsing

---
 compiler/parse/src/ident.rs                  | 121 +++++++------
 compiler/reporting/src/error/canonicalize.rs | 172 ++++++++++++++++++-
 compiler/reporting/src/error/parse.rs        |   2 +-
 compiler/reporting/tests/test_reporting.rs   |  17 +-
 4 files changed, 242 insertions(+), 70 deletions(-)

diff --git a/compiler/parse/src/ident.rs b/compiler/parse/src/ident.rs
index 639fca2f3b..963f707fa5 100644
--- a/compiler/parse/src/ident.rs
+++ b/compiler/parse/src/ident.rs
@@ -299,25 +299,33 @@ pub enum BadIdent {
     WeirdDotQualified(Row, Col),
     DoubleDot(Row, Col),
     StrayDot(Row, Col),
+    StrayAt(Row, Col),
+    BadPrivateTag(Row, Col),
 }
 
-/// Parse an identifier into a string.
-///
-/// This is separate from the `ident` Parser because string interpolation
-/// wants to use it this way.
+fn chomp_lowercase_part(buffer: &[u8]) -> Result<&str, Progress> {
+    chomp_part(|c: char| c.is_lowercase(), buffer)
+}
 
-/// a `.foo` accessor function
-fn chomp_accessor(buffer: &[u8], row: Row, col: Col) -> Result<&str, BadIdent> {
+fn chomp_uppercase_part(buffer: &[u8]) -> Result<&str, Progress> {
+    chomp_part(|c: char| c.is_uppercase(), buffer)
+}
+
+#[inline(always)]
+fn chomp_part<F>(leading_is_good: F, buffer: &[u8]) -> Result<&str, Progress>
+where
+    F: Fn(char) -> bool,
+{
     // assumes the leading `.` has been chomped already
     use encode_unicode::CharExt;
 
     let mut chomped = 0;
 
     if let Ok((ch, width)) = char::from_utf8_slice_start(&buffer[chomped..]) {
-        if ch.is_lowercase() {
+        if leading_is_good(ch) {
             chomped += width;
         } else {
-            return Err(BadIdent::StrayDot(row, col + 1));
+            return Err(NoProgress);
         }
     }
 
@@ -331,17 +339,56 @@ fn chomp_accessor(buffer: &[u8], row: Row, col: Col) -> Result<&str, BadIdent> {
     }
 
     if chomped == 0 {
-        Err(BadIdent::StrayDot(row, col + 1))
-    } else if let Ok(('.', _)) = char::from_utf8_slice_start(&buffer[chomped..]) {
-        Err(BadIdent::WeirdAccessor(row, col))
+        Err(NoProgress)
     } else {
         let name = unsafe { std::str::from_utf8_unchecked(&buffer[..chomped]) };
 
-        dbg!(name);
         Ok(name)
     }
 }
 
+/// a `.foo` accessor function
+fn chomp_accessor(buffer: &[u8], row: Row, col: Col) -> Result<&str, BadIdent> {
+    // assumes the leading `.` has been chomped already
+    use encode_unicode::CharExt;
+
+    match chomp_lowercase_part(buffer) {
+        Ok(name) => {
+            let chomped = name.len();
+
+            if let Ok(('.', _)) = char::from_utf8_slice_start(&buffer[chomped..]) {
+                Err(BadIdent::WeirdAccessor(row, col))
+            } else {
+                Ok(name)
+            }
+        }
+        Err(_) => {
+            // we've already made progress with the initial `.`
+            Err(BadIdent::StrayDot(row, col + 1))
+        }
+    }
+}
+
+/// a `@Token` private tag
+fn chomp_private_tag(buffer: &[u8], row: Row, col: Col) -> Result<&str, BadIdent> {
+    // assumes the leading `@` has NOT been chomped already
+    debug_assert_eq!(buffer.get(0), Some(&b'@'));
+    use encode_unicode::CharExt;
+
+    match chomp_uppercase_part(&buffer[1..]) {
+        Ok(name) => {
+            let chomped = 1 + name.len();
+
+            if let Ok(('.', _)) = char::from_utf8_slice_start(&buffer[chomped..]) {
+                Err(BadIdent::BadPrivateTag(row, col + chomped as u16))
+            } else {
+                Ok(name)
+            }
+        }
+        Err(_) => Err(BadIdent::BadPrivateTag(row, col + 1)),
+    }
+}
+
 fn parse_ident_help_help<'a>(
     arena: &'a Bump,
     mut state: State<'a>,
@@ -350,7 +397,6 @@ fn parse_ident_help_help<'a>(
     let mut noncapitalized_parts: Vec<&'a str> = Vec::new_in(arena);
     let mut is_capitalized;
     let is_accessor_fn;
-    let mut is_private_tag = false;
 
     let bytes = state.bytes;
     let mut chomped_capitalized = 0;
@@ -387,35 +433,17 @@ fn parse_ident_help_help<'a>(
                     Err(fail) => return Err((MadeProgress, fail, state)),
                 }
             } else if first_ch == '@' {
-                state = advance_state!(state, bytes_parsed)?;
+                match chomp_private_tag(state.bytes, state.line, state.column) {
+                    Ok(tagname) => {
+                        let bytes_parsed = 1 + tagname.len();
 
-                // '@' must always be followed by a capital letter!
-                match peek_utf8_char(&state) {
-                    Ok((next_ch, next_bytes_parsed)) => {
-                        if next_ch.is_uppercase() {
-                            state = advance_state!(state, next_bytes_parsed)?;
+                        state = advance_state!(state, bytes_parsed)?;
 
-                            part_buf.push('@');
-                            part_buf.push(next_ch);
-                            chomped_part_buf += 1 + next_bytes_parsed;
-
-                            is_private_tag = true;
-                            is_capitalized = true;
-                            is_accessor_fn = false;
-                        } else {
-                            return Err((
-                                MadeProgress,
-                                BadIdent::PrivateTagNotUppercase(state.line, state.column),
-                                state,
-                            ));
-                        }
+                        return Ok((MadeProgress, (Ident::PrivateTag(tagname), None), state));
                     }
-                    Err(_reason) => {
-                        return Err((
-                            MadeProgress,
-                            BadIdent::PrivateTagNotUppercase(state.line, state.column),
-                            state,
-                        ));
+                    Err(fail) => {
+                        state = advance_state!(state, 1)?;
+                        return Err((MadeProgress, fail, state));
                     }
                 }
             } else {
@@ -555,7 +583,7 @@ fn parse_ident_help_help<'a>(
     let answer = if is_accessor_fn {
         // Handle accessor functions first because they have the strictest requirements.
         // Accessor functions may have exactly 1 noncapitalized part, and no capitalzed parts.
-        if cparts == 0 && noncapitalized_parts.len() == 1 && !is_private_tag {
+        if cparts == 0 && noncapitalized_parts.len() == 1 {
             // an accessor starts with a `.`, but we drop that from the name
             let value = unsafe {
                 std::str::from_utf8_unchecked(&bytes[1 + chomped..1 + chomped + chomped_part_buf])
@@ -585,11 +613,7 @@ fn parse_ident_help_help<'a>(
             1 => {
                 let chomped = chomped_capitalized;
                 let value = unsafe { std::str::from_utf8_unchecked(&bytes[..chomped]) };
-                if is_private_tag {
-                    Ident::PrivateTag(value)
-                } else {
-                    Ident::GlobalTag(value)
-                }
+                Ident::GlobalTag(value)
             }
             _ => {
                 // This is a qualified tag, which is not allowed!
@@ -600,13 +624,6 @@ fn parse_ident_help_help<'a>(
                 ));
             }
         }
-    } else if is_private_tag {
-        // This is qualified field access with an '@' in front, which does not make sense!
-        return Err((
-            MadeProgress,
-            BadIdent::PrivateTagFieldAccess(state.line, state.column),
-            state,
-        ));
     } else {
         // We have multiple noncapitalized parts, so this must be field access.
         let module_name = if cparts == 0 {
diff --git a/compiler/reporting/src/error/canonicalize.rs b/compiler/reporting/src/error/canonicalize.rs
index 85fc4da8d1..f19637f2c7 100644
--- a/compiler/reporting/src/error/canonicalize.rs
+++ b/compiler/reporting/src/error/canonicalize.rs
@@ -1,4 +1,5 @@
 use roc_collections::all::MutSet;
+use roc_parse::parser::{Col, Row};
 use roc_problem::can::PrecedenceProblem::BothNonAssociative;
 use roc_problem::can::{FloatErrorKind, IntErrorKind, Problem, RuntimeError};
 use roc_region::all::Region;
@@ -450,14 +451,106 @@ fn to_bad_ident_expr_report<'b>(
             ])
         }
 
-        PrivateTagFieldAccess(_row, _col) => alloc.stack(vec![
-            alloc.reflow("I am very confused by this field access:"),
-            alloc.region(surroundings),
-            alloc.concat(vec![
-                alloc.reflow(r"It looks like a record field access on a private tag.")
-            ]),
-        ]),
-        _ => todo!(),
+        PrivateTagFieldAccess(row, col) => {
+            let region =
+                Region::from_rows_cols(surroundings.start_line, surroundings.start_col, row, col);
+            alloc.stack(vec![
+                alloc.reflow("I am very confused by this field access:"),
+                alloc.region_with_subregion(surroundings, region),
+                alloc.concat(vec![
+                    alloc.reflow(r"It looks like a record field access on a private tag.")
+                ]),
+            ])
+        }
+
+        Underscore(row, col) => {
+            let region =
+                Region::from_rows_cols(surroundings.start_line, surroundings.start_col, row, col);
+            alloc.stack(vec![
+                alloc.reflow("Underscores are not allowed in identifier names:"),
+                alloc.region_with_subregion(surroundings, region),
+                alloc.concat(vec![alloc.reflow(
+                    r"I recommend using camelCase, it is the standard in the Roc ecosystem.",
+                )]),
+            ])
+        }
+
+        DoubleDot(row, col) => {
+            let region =
+                Region::from_rows_cols(surroundings.start_line, surroundings.start_col, row, col);
+            alloc.stack(vec![
+                alloc.reflow("I am very confused by these two dots in a row:"),
+                alloc.region_with_subregion(surroundings, region),
+                alloc.concat(vec![
+                    alloc.reflow(r"There always needs to be a name after a dot.")
+                ]),
+            ])
+        }
+
+        StrayAt(row, col) => {
+            let region =
+                Region::from_rows_cols(surroundings.start_line, surroundings.start_col, row, col);
+            alloc.stack(vec![
+                alloc.reflow("I am very confused by this @ symbol"),
+                alloc.region_with_subregion(surroundings, region),
+                alloc.concat(vec![alloc.reflow(r"I expected a private tag.")]),
+            ])
+        }
+
+        BadPrivateTag(row, col) => {
+            use BadIdentNext::*;
+            match what_is_next(alloc.src_lines, row, col) {
+                LowercaseAccess(width) => {
+                    let region = Region::from_rows_cols(row, col, row, col + width);
+                    alloc.stack(vec![
+                        alloc.reflow("I am very confused by this field access:"),
+                        alloc.region_with_subregion(surroundings, region),
+                        alloc.concat(vec![
+                            alloc.reflow(r"It looks like a record field access on a private tag.")
+                        ]),
+                    ])
+                }
+                UppercaseAccess(width) => {
+                    let region = Region::from_rows_cols(row, col, row, col + width);
+                    alloc.stack(vec![
+                        alloc.reflow("I am very confused by this expression:"),
+                        alloc.region_with_subregion(surroundings, region),
+                        alloc.concat(vec![
+                            alloc.reflow(
+                                r"Looks like a private tag is treated like a module name. ",
+                            ),
+                            alloc.reflow(r"Maybe you wanted a qualified name, like "),
+                            alloc.parser_suggestion("Json.Decode.string"),
+                            alloc.text("?"),
+                        ]),
+                    ])
+                }
+                Other(Some(c)) if c.is_lowercase() => {
+                    let region = Region::from_rows_cols(
+                        surroundings.start_line,
+                        surroundings.start_col + 1,
+                        row,
+                        col + 1,
+                    );
+                    alloc.stack(vec![
+                        alloc.reflow("I am trying to parse a private tag here:"),
+                        alloc.region_with_subregion(surroundings, region),
+                        alloc.concat(vec![
+                            alloc.reflow(r"But after the "),
+                            alloc.keyword("@"),
+                            alloc.reflow(r" symbol I found a lowercase letter. "),
+                            alloc.reflow(r"All tag names (global and private)"),
+                            alloc.reflow(r" must start with an uppercase letter, like "),
+                            alloc.parser_suggestion("@UUID"),
+                            alloc.reflow(" or "),
+                            alloc.parser_suggestion("@Secrets"),
+                            alloc.reflow("."),
+                        ]),
+                    ])
+                }
+                other => todo!("{:?}", other),
+            }
+        }
     }
 }
 
@@ -591,6 +684,69 @@ fn to_bad_ident_pattern_report<'b>(
     }
 }
 
+#[derive(Debug)]
+enum BadIdentNext<'a> {
+    LowercaseAccess(u16),
+    UppercaseAccess(u16),
+    NumberAccess(u16),
+    Keyword(&'a str),
+    DanglingDot,
+    Other(Option<char>),
+}
+
+fn what_is_next<'a>(source_lines: &'a [&'a str], row: Row, col: Col) -> BadIdentNext<'a> {
+    let row_index = row as usize;
+    let col_index = col as usize;
+    match source_lines.get(row_index) {
+        None => BadIdentNext::Other(None),
+        Some(line) => {
+            let chars = &line[col_index..];
+            let mut it = chars.chars();
+
+            match roc_parse::keyword::KEYWORDS
+                .iter()
+                .find(|keyword| crate::error::parse::starts_with_keyword(chars, keyword))
+            {
+                Some(keyword) => BadIdentNext::Keyword(keyword),
+                None => match it.next() {
+                    None => BadIdentNext::Other(None),
+                    Some('.') => match it.next() {
+                        Some(c) if c.is_lowercase() => {
+                            BadIdentNext::LowercaseAccess(2 + till_whitespace(it) as u16)
+                        }
+                        Some(c) if c.is_uppercase() => {
+                            BadIdentNext::UppercaseAccess(2 + till_whitespace(it) as u16)
+                        }
+                        Some(c) if c.is_ascii_digit() => {
+                            BadIdentNext::NumberAccess(2 + till_whitespace(it) as u16)
+                        }
+                        _ => BadIdentNext::DanglingDot,
+                    },
+                    Some(c) => BadIdentNext::Other(Some(c)),
+                },
+            }
+        }
+    }
+}
+
+fn till_whitespace<I>(mut it: I) -> usize
+where
+    I: Iterator<Item = char>,
+{
+    let mut chomped = 0;
+
+    while let Some(c) = it.next() {
+        if c.is_ascii_whitespace() || c == '#' {
+            break;
+        } else {
+            chomped += 1;
+            continue;
+        }
+    }
+
+    chomped
+}
+
 fn pretty_runtime_error<'b>(
     alloc: &'b RocDocAllocator<'b>,
     runtime_error: RuntimeError,
diff --git a/compiler/reporting/src/error/parse.rs b/compiler/reporting/src/error/parse.rs
index 177707a186..a1a5a687b3 100644
--- a/compiler/reporting/src/error/parse.rs
+++ b/compiler/reporting/src/error/parse.rs
@@ -3012,7 +3012,7 @@ fn what_is_next<'a>(source_lines: &'a [&'a str], row: Row, col: Col) -> Next<'a>
     }
 }
 
-fn starts_with_keyword(rest_of_line: &str, keyword: &str) -> bool {
+pub fn starts_with_keyword(rest_of_line: &str, keyword: &str) -> bool {
     if let Some(stripped) = rest_of_line.strip_prefix(keyword) {
         match stripped.chars().next() {
             None => true,
diff --git a/compiler/reporting/tests/test_reporting.rs b/compiler/reporting/tests/test_reporting.rs
index dfd2bee8b8..9e8efc54db 100644
--- a/compiler/reporting/tests/test_reporting.rs
+++ b/compiler/reporting/tests/test_reporting.rs
@@ -4147,15 +4147,14 @@ mod test_reporting {
             indoc!(
                 r#"
                 ── SYNTAX PROBLEM ──────────────────────────────────────────────────────────────
-
-                I am trying to parse a qualified name here:
-
+                
+                I am very confused by this expression:
+                
                 1│  @Foo.Bar
-                            ^
-
-                This looks like a qualified tag name to me, but tags cannot be
-                qualified! Maybe you wanted a qualified name, something like
-                Json.Decode.string?
+                        ^^^^
+                
+                Looks like a private tag is treated like a module name. Maybe you
+                wanted a qualified name, like Json.Decode.string?
             "#
             ),
         )
@@ -5523,7 +5522,7 @@ mod test_reporting {
                 I am very confused by this field access:
 
                 1│  @UUID.bar
-                    ^^^^^^^^^
+                         ^^^^
 
                 It looks like a record field access on a private tag.
             "#

From 796ec0032375ae7305ff3e794bc3871cfacc9217 Mon Sep 17 00:00:00 2001
From: Folkert <folkert@folkertdev.nl>
Date: Wed, 10 Mar 2021 20:21:51 +0100
Subject: [PATCH 41/74] wip faster ident parsing

---
 compiler/parse/src/ident.rs | 186 ++++++++++++++++++++++++++++++++++--
 1 file changed, 177 insertions(+), 9 deletions(-)

diff --git a/compiler/parse/src/ident.rs b/compiler/parse/src/ident.rs
index 963f707fa5..bd2f7c06a2 100644
--- a/compiler/parse/src/ident.rs
+++ b/compiler/parse/src/ident.rs
@@ -220,7 +220,7 @@ pub fn parse_ident_help<'a>(
     let initial = state.clone();
 
     match parse_ident_help_help(arena, state) {
-        Ok((progress, (ident, _), state)) => {
+        Ok((progress, ident, state)) => {
             if let Ident::Access { module_name, parts } = ident {
                 if module_name.is_empty() {
                     if let Some(first) = parts.first() {
@@ -389,10 +389,182 @@ fn chomp_private_tag(buffer: &[u8], row: Row, col: Col) -> Result<&str, BadIdent
     }
 }
 
+fn chomp_identifier_chain<'a>(
+    arena: &'a Bump,
+    buffer: &'a [u8],
+    row: Row,
+    col: Col,
+) -> Result<(u16, Ident<'a>), (u16, BadIdent)> {
+    use encode_unicode::CharExt;
+
+    let first_is_uppercase;
+    let mut chomped = 0;
+
+    match char::from_utf8_slice_start(&buffer[chomped..]) {
+        Ok((ch, width)) => match ch {
+            '.' => match chomp_accessor(&buffer[1..], row, col) {
+                Ok(accessor) => {
+                    let bytes_parsed = 1 + accessor.len();
+
+                    return Ok((bytes_parsed as u16, Ident::AccessorFunction(accessor)));
+                }
+                Err(fail) => return Err((1, fail)),
+            },
+            '@' => match chomp_private_tag(buffer, row, col) {
+                Ok(tagname) => {
+                    let bytes_parsed = tagname.len();
+
+                    return Ok((bytes_parsed as u16, Ident::PrivateTag(tagname)));
+                }
+                Err(fail) => return Err((1, fail)),
+            },
+            c if c.is_alphabetic() => {
+                // fall through
+                chomped += width;
+                first_is_uppercase = c.is_uppercase();
+            }
+            _ => {
+                return Err((0, BadIdent::Start(row, col)));
+            }
+        },
+        Err(_) => return Err((0, BadIdent::Start(row, col))),
+    }
+
+    while let Ok((ch, width)) = char::from_utf8_slice_start(&buffer[chomped..]) {
+        if ch.is_alphabetic() || ch.is_ascii_digit() {
+            chomped += width;
+        } else {
+            // we're done
+            break;
+        }
+    }
+
+    if let Ok(('.', _)) = char::from_utf8_slice_start(&buffer[chomped..]) {
+        let module_name = if first_is_uppercase {
+            match chomp_module_chain(&buffer[chomped..]) {
+                Ok(width) => {
+                    chomped += width as usize;
+                    unsafe { std::str::from_utf8_unchecked(&buffer[..chomped + width as usize]) }
+                }
+                Err(MadeProgress) => todo!(),
+                Err(NoProgress) => {
+                    chomped += 1;
+                    ""
+                }
+            }
+        } else {
+            ""
+        };
+
+        let mut parts = Vec::with_capacity_in(4, arena);
+
+        if !first_is_uppercase {
+            let first_part = unsafe { std::str::from_utf8_unchecked(&buffer[..chomped]) };
+            parts.push(first_part);
+        }
+
+        match chomp_access_chain(&buffer[chomped..], &mut parts) {
+            Ok(width) => {
+                chomped += width as usize;
+
+                let ident = Ident::Access {
+                    module_name,
+                    parts: parts.into_bump_slice(),
+                };
+
+                Ok((chomped as u16, ident))
+            }
+            Err(MadeProgress) => todo!(),
+            Err(NoProgress) => Err((chomped as u16 + 1, BadIdent::StrayDot(row, col))),
+        }
+    } else if first_is_uppercase {
+        // just one segment, starting with an uppercase letter; that's a global tag
+        let value = unsafe { std::str::from_utf8_unchecked(&buffer[..chomped]) };
+        Ok((chomped as u16, Ident::GlobalTag(value)))
+    } else {
+        // just one segment, starting with a lowercase letter; that's a normal identifier
+        let value = unsafe { std::str::from_utf8_unchecked(&buffer[..chomped]) };
+        let ident = Ident::Access {
+            module_name: "",
+            parts: arena.alloc([value]),
+        };
+        Ok((chomped as u16, ident))
+    }
+}
+
+fn chomp_module_chain<'a>(buffer: &'a [u8]) -> Result<u16, Progress> {
+    let mut chomped = 0;
+    // number of dots (equivalently parts) we've seen
+    let mut i = 1;
+
+    loop {
+        match chomp_uppercase_part(&buffer[chomped + i..]) {
+            Ok(name) => {
+                chomped += name.len();
+                i += 1;
+            }
+            Err(MadeProgress) => return Err(MadeProgress),
+            Err(NoProgress) => break,
+        }
+    }
+
+    if chomped == 0 {
+        Err(NoProgress)
+    } else {
+        Ok((chomped + i) as u16)
+    }
+}
+
+fn chomp_access_chain<'a>(buffer: &'a [u8], parts: &mut Vec<'a, &'a str>) -> Result<u16, Progress> {
+    let mut chomped = 0;
+    let mut i = 1;
+
+    loop {
+        match chomp_lowercase_part(&buffer[chomped + i..]) {
+            Ok(name) => {
+                let value = unsafe {
+                    std::str::from_utf8_unchecked(&buffer[chomped + i..chomped + i + name.len()])
+                };
+                parts.push(value);
+
+                chomped += name.len();
+                i += 1;
+            }
+            Err(MadeProgress) => return Err(MadeProgress),
+            Err(NoProgress) => break,
+        }
+    }
+
+    if chomped == 0 {
+        Err(NoProgress)
+    } else {
+        Ok((chomped + i) as u16)
+    }
+}
+
+/// a `Ok` global tag
+fn chomp_global_tag(buffer: &[u8], row: Row, col: Col) -> Result<&str, BadIdent> {
+    debug_assert!(((*buffer.get(0).unwrap()) as char).is_uppercase());
+    use encode_unicode::CharExt;
+
+    match chomp_uppercase_part(&buffer[1..]) {
+        Ok(name) => {
+            let chomped = 1 + name.len();
+
+            if let Ok(('.', _)) = char::from_utf8_slice_start(&buffer[chomped..]) {
+                Err(BadIdent::BadPrivateTag(row, col + chomped as u16))
+            } else {
+                Ok(name)
+            }
+        }
+        Err(_) => Err(BadIdent::BadPrivateTag(row, col + 1)),
+    }
+}
+
 fn parse_ident_help_help<'a>(
     arena: &'a Bump,
     mut state: State<'a>,
-) -> ParseResult<'a, (Ident<'a>, Option<char>), BadIdent> {
+) -> ParseResult<'a, Ident<'a>, BadIdent> {
     let mut part_buf = String::new_in(arena); // The current "part" (parts are dot-separated.)
     let mut noncapitalized_parts: Vec<&'a str> = Vec::new_in(arena);
     let mut is_capitalized;
@@ -424,11 +596,7 @@ fn parse_ident_help_help<'a>(
 
                         state = advance_state!(state, bytes_parsed)?;
 
-                        return Ok((
-                            MadeProgress,
-                            (Ident::AccessorFunction(accessor), None),
-                            state,
-                        ));
+                        return Ok((MadeProgress, Ident::AccessorFunction(accessor), state));
                     }
                     Err(fail) => return Err((MadeProgress, fail, state)),
                 }
@@ -439,7 +607,7 @@ fn parse_ident_help_help<'a>(
 
                         state = advance_state!(state, bytes_parsed)?;
 
-                        return Ok((MadeProgress, (Ident::PrivateTag(tagname), None), state));
+                        return Ok((MadeProgress, Ident::PrivateTag(tagname), state));
                     }
                     Err(fail) => {
                         state = advance_state!(state, 1)?;
@@ -639,5 +807,5 @@ fn parse_ident_help_help<'a>(
         }
     };
 
-    Ok((Progress::MadeProgress, (answer, None), state))
+    Ok((Progress::MadeProgress, answer, state))
 }

From 61fc05dace4c0919de1f0ba63b1888d3202fc893 Mon Sep 17 00:00:00 2001
From: Folkert <folkert@folkertdev.nl>
Date: Wed, 10 Mar 2021 21:42:37 +0100
Subject: [PATCH 42/74] working report tests

---
 compiler/parse/src/ident.rs                  | 124 +++++++++++--------
 compiler/reporting/src/error/canonicalize.rs |   6 +-
 compiler/reporting/tests/test_reporting.rs   |  20 +--
 3 files changed, 84 insertions(+), 66 deletions(-)

diff --git a/compiler/parse/src/ident.rs b/compiler/parse/src/ident.rs
index bd2f7c06a2..6a55b8a049 100644
--- a/compiler/parse/src/ident.rs
+++ b/compiler/parse/src/ident.rs
@@ -444,13 +444,10 @@ fn chomp_identifier_chain<'a>(
             match chomp_module_chain(&buffer[chomped..]) {
                 Ok(width) => {
                     chomped += width as usize;
-                    unsafe { std::str::from_utf8_unchecked(&buffer[..chomped + width as usize]) }
+                    unsafe { std::str::from_utf8_unchecked(&buffer[..chomped]) }
                 }
                 Err(MadeProgress) => todo!(),
-                Err(NoProgress) => {
-                    chomped += 1;
-                    ""
-                }
+                Err(NoProgress) => unsafe { std::str::from_utf8_unchecked(&buffer[..chomped]) },
             }
         } else {
             ""
@@ -474,9 +471,27 @@ fn chomp_identifier_chain<'a>(
 
                 Ok((chomped as u16, ident))
             }
-            Err(MadeProgress) => todo!(),
-            Err(NoProgress) => Err((chomped as u16 + 1, BadIdent::StrayDot(row, col))),
+            Err(0) if !module_name.is_empty() => Err((
+                chomped as u16,
+                BadIdent::QualifiedTag(row, chomped as u16 + col),
+            )),
+            Err(1) if parts.is_empty() => Err((
+                chomped as u16 + 1,
+                BadIdent::WeirdDotQualified(row, chomped as u16 + col + 1),
+            )),
+            Err(width) => Err((
+                chomped as u16 + width,
+                BadIdent::WeirdDotAccess(row, chomped as u16 + col + width),
+            )),
         }
+    } else if let Ok(('_', _)) = char::from_utf8_slice_start(&buffer[chomped..]) {
+        // we don't allow underscores in the middle of an identifier
+        // but still parse them (and generate a malformed identifier)
+        // to give good error messages for this case
+        Err((
+            chomped as u16 + 1,
+            BadIdent::Underscore(row, col + chomped as u16 + 1),
+        ))
     } else if first_is_uppercase {
         // just one segment, starting with an uppercase letter; that's a global tag
         let value = unsafe { std::str::from_utf8_unchecked(&buffer[..chomped]) };
@@ -494,70 +509,59 @@ fn chomp_identifier_chain<'a>(
 
 fn chomp_module_chain<'a>(buffer: &'a [u8]) -> Result<u16, Progress> {
     let mut chomped = 0;
-    // number of dots (equivalently parts) we've seen
-    let mut i = 1;
 
-    loop {
-        match chomp_uppercase_part(&buffer[chomped + i..]) {
-            Ok(name) => {
-                chomped += name.len();
-                i += 1;
-            }
-            Err(MadeProgress) => return Err(MadeProgress),
-            Err(NoProgress) => break,
+    while let Some(b'.') = buffer.get(chomped) {
+        match &buffer.get(chomped + 1..) {
+            Some(slice) => match chomp_uppercase_part(slice) {
+                Ok(name) => {
+                    chomped += name.len() + 1;
+                }
+                Err(MadeProgress) => return Err(MadeProgress),
+                Err(NoProgress) => break,
+            },
+            None => return Err(MadeProgress),
         }
     }
 
     if chomped == 0 {
         Err(NoProgress)
     } else {
-        Ok((chomped + i) as u16)
+        Ok(chomped as u16)
     }
 }
 
-fn chomp_access_chain<'a>(buffer: &'a [u8], parts: &mut Vec<'a, &'a str>) -> Result<u16, Progress> {
+fn chomp_access_chain<'a>(buffer: &'a [u8], parts: &mut Vec<'a, &'a str>) -> Result<u16, u16> {
     let mut chomped = 0;
-    let mut i = 1;
 
-    loop {
-        match chomp_lowercase_part(&buffer[chomped + i..]) {
-            Ok(name) => {
-                let value = unsafe {
-                    std::str::from_utf8_unchecked(&buffer[chomped + i..chomped + i + name.len()])
-                };
-                parts.push(value);
+    while let Some(b'.') = buffer.get(chomped) {
+        match &buffer.get(chomped + 1..) {
+            Some(slice) => match chomp_lowercase_part(slice) {
+                Ok(name) => {
+                    let value = unsafe {
+                        std::str::from_utf8_unchecked(
+                            &buffer[chomped + 1..chomped + 1 + name.len()],
+                        )
+                    };
+                    parts.push(value);
 
-                chomped += name.len();
-                i += 1;
-            }
-            Err(MadeProgress) => return Err(MadeProgress),
-            Err(NoProgress) => break,
+                    chomped += name.len() + 1;
+                }
+                Err(_) => return Err(chomped as u16 + 1),
+            },
+            None => return Err(chomped as u16 + 1),
         }
     }
 
+    dbg!(&parts);
+
+    let value = unsafe { std::str::from_utf8_unchecked(&buffer[chomped..]) };
+
+    dbg!(value);
+
     if chomped == 0 {
-        Err(NoProgress)
+        Err(0)
     } else {
-        Ok((chomped + i) as u16)
-    }
-}
-
-/// a `Ok` global tag
-fn chomp_global_tag(buffer: &[u8], row: Row, col: Col) -> Result<&str, BadIdent> {
-    debug_assert!(((*buffer.get(0).unwrap()) as char).is_uppercase());
-    use encode_unicode::CharExt;
-
-    match chomp_uppercase_part(&buffer[1..]) {
-        Ok(name) => {
-            let chomped = 1 + name.len();
-
-            if let Ok(('.', _)) = char::from_utf8_slice_start(&buffer[chomped..]) {
-                Err(BadIdent::BadPrivateTag(row, col + chomped as u16))
-            } else {
-                Ok(name)
-            }
-        }
-        Err(_) => Err(BadIdent::BadPrivateTag(row, col + 1)),
+        Ok(chomped as u16)
     }
 }
 
@@ -565,6 +569,20 @@ fn parse_ident_help_help<'a>(
     arena: &'a Bump,
     mut state: State<'a>,
 ) -> ParseResult<'a, Ident<'a>, BadIdent> {
+    match chomp_identifier_chain(arena, state.bytes, state.line, state.column) {
+        Ok((width, ident)) => {
+            state = advance_state!(state, width as usize)?;
+            return Ok((MadeProgress, ident, state));
+        }
+        Err((0, fail)) => {
+            return Err((NoProgress, fail, state));
+        }
+        Err((width, fail)) => {
+            state = advance_state!(state, width as usize)?;
+            return Err((MadeProgress, fail, state));
+        }
+    }
+
     let mut part_buf = String::new_in(arena); // The current "part" (parts are dot-separated.)
     let mut noncapitalized_parts: Vec<&'a str> = Vec::new_in(arena);
     let mut is_capitalized;
diff --git a/compiler/reporting/src/error/canonicalize.rs b/compiler/reporting/src/error/canonicalize.rs
index f19637f2c7..4357a63a27 100644
--- a/compiler/reporting/src/error/canonicalize.rs
+++ b/compiler/reporting/src/error/canonicalize.rs
@@ -358,14 +358,14 @@ fn to_bad_ident_expr_report<'b>(
             let region = Region::from_row_col(row, col);
 
             alloc.stack(vec![
-                alloc.reflow(r"I trying to parse a record field accessor here:"),
+                alloc.reflow(r"I trying to parse a record field access here:"),
                 alloc.region_with_subregion(surroundings, region),
                 alloc.concat(vec![
-                    alloc.reflow("Something like "),
+                    alloc.reflow("So I expect to see a lowercase letter next, like "),
                     alloc.parser_suggestion(".name"),
                     alloc.reflow(" or "),
                     alloc.parser_suggestion(".height"),
-                    alloc.reflow(" that accesses a value from a record."),
+                    alloc.reflow("."),
                 ]),
             ])
         }
diff --git a/compiler/reporting/tests/test_reporting.rs b/compiler/reporting/tests/test_reporting.rs
index 9e8efc54db..3bd5379642 100644
--- a/compiler/reporting/tests/test_reporting.rs
+++ b/compiler/reporting/tests/test_reporting.rs
@@ -4124,13 +4124,13 @@ mod test_reporting {
             indoc!(
                 r#"
                 ── SYNTAX PROBLEM ──────────────────────────────────────────────────────────────
-
-                I trying to parse a record field accessor here:
-
+                
+                I trying to parse a record field access here:
+                
                 1│  foo.bar.
                             ^
-
-                Something like .name or .height that accesses a value from a record.
+                
+                So I expect to see a lowercase letter next, like .name or .height.
             "#
             ),
         )
@@ -5470,13 +5470,13 @@ mod test_reporting {
             indoc!(
                 r#"
                 ── SYNTAX PROBLEM ──────────────────────────────────────────────────────────────
-
-                I trying to parse a record field accessor here:
-
+                
+                I trying to parse a record field access here:
+                
                 1│  Num.add . 23
                              ^
-
-                Something like .name or .height that accesses a value from a record.
+                
+                So I expect to see a lowercase letter next, like .name or .height.
             "#
             ),
         )

From e7bbfe96dbc0f8778b25db8fa984dcb57ece21de Mon Sep 17 00:00:00 2001
From: Folkert <folkert@folkertdev.nl>
Date: Wed, 10 Mar 2021 21:46:34 +0100
Subject: [PATCH 43/74] fix parse tests

---
 compiler/parse/src/ident.rs        | 9 +++++----
 compiler/parse/tests/test_parse.rs | 2 +-
 2 files changed, 6 insertions(+), 5 deletions(-)

diff --git a/compiler/parse/src/ident.rs b/compiler/parse/src/ident.rs
index 6a55b8a049..447afa8cc8 100644
--- a/compiler/parse/src/ident.rs
+++ b/compiler/parse/src/ident.rs
@@ -377,12 +377,13 @@ fn chomp_private_tag(buffer: &[u8], row: Row, col: Col) -> Result<&str, BadIdent
 
     match chomp_uppercase_part(&buffer[1..]) {
         Ok(name) => {
-            let chomped = 1 + name.len();
+            let width = 1 + name.len();
 
-            if let Ok(('.', _)) = char::from_utf8_slice_start(&buffer[chomped..]) {
-                Err(BadIdent::BadPrivateTag(row, col + chomped as u16))
+            if let Ok(('.', _)) = char::from_utf8_slice_start(&buffer[width..]) {
+                Err(BadIdent::BadPrivateTag(row, col + width as u16))
             } else {
-                Ok(name)
+                let value = unsafe { std::str::from_utf8_unchecked(&buffer[..width]) };
+                Ok(value)
             }
         }
         Err(_) => Err(BadIdent::BadPrivateTag(row, col + 1)),
diff --git a/compiler/parse/tests/test_parse.rs b/compiler/parse/tests/test_parse.rs
index 58dfb65174..412898dfb4 100644
--- a/compiler/parse/tests/test_parse.rs
+++ b/compiler/parse/tests/test_parse.rs
@@ -1005,7 +1005,7 @@ mod test_parse {
         use roc_parse::ident::BadIdent;
 
         let arena = Bump::new();
-        let expected = Expr::MalformedIdent("@One.Two.Whee", BadIdent::QualifiedTag(0, 13));
+        let expected = Expr::MalformedIdent("@One.Two.Whee", BadIdent::BadPrivateTag(0, 4));
         let actual = parse_expr_with(&arena, "@One.Two.Whee");
 
         assert_eq!(Ok(expected), actual);

From 864390a89aafca6db28bb0f96bcdded64aec3663 Mon Sep 17 00:00:00 2001
From: Folkert <folkert@folkertdev.nl>
Date: Wed, 10 Mar 2021 21:56:19 +0100
Subject: [PATCH 44/74] use new ident parser

---
 compiler/parse/src/ident.rs | 258 +-----------------------------------
 1 file changed, 3 insertions(+), 255 deletions(-)

diff --git a/compiler/parse/src/ident.rs b/compiler/parse/src/ident.rs
index 447afa8cc8..59c3d46f28 100644
--- a/compiler/parse/src/ident.rs
+++ b/compiler/parse/src/ident.rs
@@ -553,12 +553,6 @@ fn chomp_access_chain<'a>(buffer: &'a [u8], parts: &mut Vec<'a, &'a str>) -> Res
         }
     }
 
-    dbg!(&parts);
-
-    let value = unsafe { std::str::from_utf8_unchecked(&buffer[chomped..]) };
-
-    dbg!(value);
-
     if chomped == 0 {
         Err(0)
     } else {
@@ -573,258 +567,12 @@ fn parse_ident_help_help<'a>(
     match chomp_identifier_chain(arena, state.bytes, state.line, state.column) {
         Ok((width, ident)) => {
             state = advance_state!(state, width as usize)?;
-            return Ok((MadeProgress, ident, state));
-        }
-        Err((0, fail)) => {
-            return Err((NoProgress, fail, state));
+            Ok((MadeProgress, ident, state))
         }
+        Err((0, fail)) => Err((NoProgress, fail, state)),
         Err((width, fail)) => {
             state = advance_state!(state, width as usize)?;
-            return Err((MadeProgress, fail, state));
+            Err((MadeProgress, fail, state))
         }
     }
-
-    let mut part_buf = String::new_in(arena); // The current "part" (parts are dot-separated.)
-    let mut noncapitalized_parts: Vec<&'a str> = Vec::new_in(arena);
-    let mut is_capitalized;
-    let is_accessor_fn;
-
-    let bytes = state.bytes;
-    let mut chomped_capitalized = 0;
-    let mut cparts = 0;
-
-    let mut chomped_part_buf = 0;
-    let mut chomped = 0;
-
-    // Identifiers and accessor functions must start with either a letter or a dot.
-    // If this starts with neither, it must be something else!
-    match peek_utf8_char(&state) {
-        Ok((first_ch, bytes_parsed)) => {
-            if first_ch.is_alphabetic() {
-                part_buf.push(first_ch);
-                chomped_part_buf += bytes_parsed;
-
-                is_capitalized = first_ch.is_uppercase();
-                is_accessor_fn = false;
-
-                state = advance_state!(state, bytes_parsed)?;
-            } else if first_ch == '.' {
-                match chomp_accessor(&state.bytes[1..], state.line, state.column) {
-                    Ok(accessor) => {
-                        let bytes_parsed = 1 + accessor.len();
-
-                        state = advance_state!(state, bytes_parsed)?;
-
-                        return Ok((MadeProgress, Ident::AccessorFunction(accessor), state));
-                    }
-                    Err(fail) => return Err((MadeProgress, fail, state)),
-                }
-            } else if first_ch == '@' {
-                match chomp_private_tag(state.bytes, state.line, state.column) {
-                    Ok(tagname) => {
-                        let bytes_parsed = 1 + tagname.len();
-
-                        state = advance_state!(state, bytes_parsed)?;
-
-                        return Ok((MadeProgress, Ident::PrivateTag(tagname), state));
-                    }
-                    Err(fail) => {
-                        state = advance_state!(state, 1)?;
-                        return Err((MadeProgress, fail, state));
-                    }
-                }
-            } else {
-                return Err((NoProgress, BadIdent::Start(state.line, state.column), state));
-            }
-        }
-        Err(_reason) => {
-            return Err((NoProgress, BadIdent::Start(state.line, state.column), state));
-        }
-    }
-
-    while !state.bytes.is_empty() {
-        match peek_utf8_char(&state) {
-            Ok((ch, width)) => {
-                // After the first character, only these are allowed:
-                //
-                // * Unicode alphabetic chars - you might name a variable `鹏` if that's clear to your readers
-                // * ASCII digits - e.g. `1` but not `¾`, both of which pass .is_numeric()
-                // * A dot ('.')
-                if ch.is_alphabetic() {
-                    if part_buf.is_empty() {
-                        // Capitalization is determined by the first character in the part.
-                        is_capitalized = ch.is_uppercase();
-                    }
-
-                    part_buf.push(ch);
-                    chomped_part_buf += width;
-                } else if ch.is_ascii_digit() {
-                    // Parts may not start with numbers!
-                    if part_buf.is_empty() {
-                        return Err((
-                            MadeProgress,
-                            BadIdent::PartStartsWithNumber(state.line, state.column),
-                            state,
-                        ));
-                    }
-
-                    part_buf.push(ch);
-                    chomped_part_buf += width;
-                } else if ch == '.' {
-                    // There are two posssible errors here:
-                    //
-                    // 1. Having two consecutive dots is an error.
-                    // 2. Having capitalized parts after noncapitalized (e.g. `foo.Bar`) is an error.
-                    if part_buf.is_empty() {
-                        return Err((
-                            MadeProgress,
-                            BadIdent::DoubleDot(state.line, state.column),
-                            state,
-                        ));
-                    }
-
-                    if is_capitalized && !noncapitalized_parts.is_empty() {
-                        return Err((
-                            MadeProgress,
-                            BadIdent::WeirdDotQualified(state.line, state.column),
-                            state,
-                        ));
-                    }
-
-                    if is_capitalized {
-                        chomped_capitalized +=
-                            chomped_part_buf + (chomped_capitalized != 0) as usize;
-                        cparts += 1;
-                    } else {
-                        let value = unsafe {
-                            std::str::from_utf8_unchecked(
-                                &bytes[chomped..chomped + chomped_part_buf],
-                            )
-                        };
-                        noncapitalized_parts.push(value);
-                    }
-
-                    // Now that we've recorded the contents of the current buffer, reset it.
-                    part_buf = String::new_in(arena);
-                    chomped += chomped_part_buf + 1;
-                    chomped_part_buf = 0;
-                } else if ch == '_' {
-                    // we don't allow underscores in the middle of an identifier
-                    // but still parse them (and generate a malformed identifier)
-                    // to give good error messages for this case
-                    state = advance_state!(state, width)?;
-                    return Err((
-                        MadeProgress,
-                        BadIdent::Underscore(state.line, state.column),
-                        state,
-                    ));
-                } else {
-                    // This must be the end of the identifier. We're done!
-
-                    break;
-                }
-
-                state = advance_state!(state, width)?;
-            }
-            Err(_reason) => {
-                //
-                return Err((
-                    MadeProgress,
-                    BadIdent::Start(state.line, state.column),
-                    state,
-                ));
-            }
-        }
-    }
-
-    if chomped_part_buf == 0 {
-        // We probably had a trailing dot, e.g. `Foo.bar.` - this is malformed!
-        //
-        // This condition might also occur if we encounter a malformed accessor like `.|`
-        //
-        // If we made it this far and don't have a next_char, then necessarily
-        // we have consumed a '.' char previously.
-        let fail = if noncapitalized_parts.is_empty() {
-            if cparts == 0 {
-                BadIdent::StrayDot(state.line, state.column)
-            } else {
-                BadIdent::WeirdDotQualified(state.line, state.column)
-            }
-        } else {
-            BadIdent::WeirdDotAccess(state.line, state.column)
-        };
-
-        return Err((MadeProgress, fail, state));
-    }
-
-    // Record the final parts.
-    if is_capitalized {
-        chomped_capitalized += chomped_part_buf + (chomped_capitalized != 0) as usize;
-        cparts += 1;
-    } else {
-        let value =
-            unsafe { std::str::from_utf8_unchecked(&bytes[chomped..chomped + chomped_part_buf]) };
-        noncapitalized_parts.push(value);
-    }
-
-    let answer = if is_accessor_fn {
-        // Handle accessor functions first because they have the strictest requirements.
-        // Accessor functions may have exactly 1 noncapitalized part, and no capitalzed parts.
-        if cparts == 0 && noncapitalized_parts.len() == 1 {
-            // an accessor starts with a `.`, but we drop that from the name
-            let value = unsafe {
-                std::str::from_utf8_unchecked(&bytes[1 + chomped..1 + chomped + chomped_part_buf])
-            };
-
-            Ident::AccessorFunction(value)
-        } else {
-            return Err((
-                MadeProgress,
-                BadIdent::WeirdAccessor(state.line, state.column),
-                state,
-            ));
-        }
-    } else if noncapitalized_parts.is_empty() {
-        // We have capitalized parts only, so this must be a tag.
-        match cparts {
-            0 => {
-                // We had neither capitalized nor noncapitalized parts,
-                // yet we made it this far. The only explanation is that this was
-                // a stray '.' drifting through the cosmos.
-                return Err((
-                    MadeProgress,
-                    BadIdent::StrayDot(state.line, state.column),
-                    state,
-                ));
-            }
-            1 => {
-                let chomped = chomped_capitalized;
-                let value = unsafe { std::str::from_utf8_unchecked(&bytes[..chomped]) };
-                Ident::GlobalTag(value)
-            }
-            _ => {
-                // This is a qualified tag, which is not allowed!
-                return Err((
-                    MadeProgress,
-                    BadIdent::QualifiedTag(state.line, state.column),
-                    state,
-                ));
-            }
-        }
-    } else {
-        // We have multiple noncapitalized parts, so this must be field access.
-        let module_name = if cparts == 0 {
-            ""
-        } else {
-            let chomped = chomped_capitalized;
-            unsafe { std::str::from_utf8_unchecked(&bytes[..chomped]) }
-        };
-
-        Ident::Access {
-            module_name,
-            parts: noncapitalized_parts.into_bump_slice(),
-        }
-    };
-
-    Ok((Progress::MadeProgress, answer, state))
 }

From 6be5f1a6b17e752c007c3a9c45b052abfd788bcc Mon Sep 17 00:00:00 2001
From: Folkert <folkert@folkertdev.nl>
Date: Wed, 10 Mar 2021 22:08:13 +0100
Subject: [PATCH 45/74] remove context stack

---
 compiler/parse/src/parser.rs | 49 ------------------------------------
 1 file changed, 49 deletions(-)

diff --git a/compiler/parse/src/parser.rs b/compiler/parse/src/parser.rs
index 51cb45bc6e..ed141d634f 100644
--- a/compiler/parse/src/parser.rs
+++ b/compiler/parse/src/parser.rs
@@ -27,8 +27,6 @@ pub struct State<'a> {
     // the first nonspace char on that line.
     pub is_indenting: bool,
 
-    pub context_stack: &'a ContextStack<'a>,
-
     /// The original length of the string, before any bytes were consumed.
     /// This is used internally by the State::bytes_consumed() function.
     ///
@@ -50,7 +48,6 @@ impl<'a> State<'a> {
             column: 0,
             indent_col: 0,
             is_indenting: true,
-            context_stack: arena.alloc(ContextStack::Nil),
             original_len: bytes.len(),
         }
     }
@@ -119,7 +116,6 @@ impl<'a> State<'a> {
                 indent_col: 0,
                 is_indenting: true,
                 original_len: self.original_len,
-                context_stack: arena.alloc(self.context_stack.clone()),
             }),
             None => Err((
                 Progress::NoProgress,
@@ -221,7 +217,6 @@ impl<'a> State<'a> {
                     column: column_usize as u16,
                     indent_col,
                     is_indenting,
-                    context_stack: arena.alloc(self.context_stack.clone()),
                     original_len: self.original_len,
                 })
             }
@@ -269,7 +264,6 @@ impl<'a> fmt::Debug for State<'a> {
         write!(f, "\n\tindent_col: {}", self.indent_col)?;
         write!(f, "\n\tis_indenting: {:?}", self.is_indenting)?;
         write!(f, "\n\toriginal_len: {}", self.original_len)?;
-        write!(f, "\n\tcontext stack: {:?}", self.context_stack)?;
         write!(f, "\n}}")
     }
 }
@@ -2199,39 +2193,6 @@ macro_rules! debug {
     };
 }
 
-#[macro_export]
-macro_rules! attempt {
-    ($attempting:expr, $parser:expr) => {
-        move |arena: &'a Bump, mut state: $crate::parser::State<'a>| {
-            let item = $crate::parser::ContextItem {
-                context: $attempting,
-                line: state.line,
-                column: state.column,
-            };
-
-            state.context_stack = arena.alloc($crate::parser::ContextStack::Cons(
-                item,
-                state.context_stack,
-            ));
-
-            $parser
-                .parse(arena, state)
-                .map(|(progress, answer, mut state)| {
-                    // If the parser suceeded, go back to what we were originally attempting.
-                    // (If it failed, that's exactly where we care what we were attempting!)
-                    match state.context_stack.uncons() {
-                        Some((_item, rest)) => {
-                            state.context_stack = rest;
-                        }
-                        None => unreachable!("context stack contains at least one element"),
-                    }
-
-                    (progress, answer, state)
-                })
-        }
-    };
-}
-
 #[macro_export]
 macro_rules! either {
     ($p1:expr, $p2:expr) => {
@@ -2315,16 +2276,6 @@ where
     map_with_arena!(parser, transform)
 }
 
-/// For some reason, some usages won't compile unless they use this instead of the macro version
-#[inline(always)]
-pub fn attempt<'a, P, Val, Error>(attempting: Attempting, parser: P) -> impl Parser<'a, Val, Error>
-where
-    P: Parser<'a, Val, Error>,
-    Error: 'a,
-{
-    attempt!(attempting, parser)
-}
-
 pub fn parse_utf8<'a>(bytes: &[u8]) -> Result<&str, SyntaxError<'a>> {
     match from_utf8(bytes) {
         Ok(string) => Ok(string),

From 55a92b50ccb395296896d765039ce42459b79c7c Mon Sep 17 00:00:00 2001
From: Folkert <folkert@folkertdev.nl>
Date: Wed, 10 Mar 2021 23:03:01 +0100
Subject: [PATCH 46/74] remove unused ident errors

---
 compiler/parse/src/ident.rs                  |   7 +-
 compiler/reporting/src/error/canonicalize.rs | 112 -------------------
 2 files changed, 1 insertion(+), 118 deletions(-)

diff --git a/compiler/parse/src/ident.rs b/compiler/parse/src/ident.rs
index 59c3d46f28..4c5b956363 100644
--- a/compiler/parse/src/ident.rs
+++ b/compiler/parse/src/ident.rs
@@ -288,18 +288,13 @@ fn malformed_identifier<'a>(
 pub enum BadIdent {
     Start(Row, Col),
     Space(BadInputError, Row, Col),
+
     Underscore(Row, Col),
     QualifiedTag(Row, Col),
-    PrivateTagNotUppercase(Row, Col),
-    PartStartsWithNumber(Row, Col),
     WeirdAccessor(Row, Col),
-    PrivateTagFieldAccess(Row, Col),
-
     WeirdDotAccess(Row, Col),
     WeirdDotQualified(Row, Col),
-    DoubleDot(Row, Col),
     StrayDot(Row, Col),
-    StrayAt(Row, Col),
     BadPrivateTag(Row, Col),
 }
 
diff --git a/compiler/reporting/src/error/canonicalize.rs b/compiler/reporting/src/error/canonicalize.rs
index 4357a63a27..dd380e4866 100644
--- a/compiler/reporting/src/error/canonicalize.rs
+++ b/compiler/reporting/src/error/canonicalize.rs
@@ -370,22 +370,6 @@ fn to_bad_ident_expr_report<'b>(
             ])
         }
 
-        PartStartsWithNumber(row, col) => {
-            let region = Region::from_row_col(row, col);
-
-            alloc.stack(vec![
-                alloc.reflow("I trying to parse a record field access here:"),
-                alloc.region_with_subregion(surroundings, region),
-                alloc.concat(vec![
-                    alloc.reflow("So I expect to see a lowercase letter next, like "),
-                    alloc.parser_suggestion(".name"),
-                    alloc.reflow(" or "),
-                    alloc.parser_suggestion(".height"),
-                    alloc.reflow("."),
-                ]),
-            ])
-        }
-
         WeirdAccessor(_row, _col) => alloc.stack(vec![
             alloc.reflow("I am very confused by this field access"),
             alloc.region(surroundings),
@@ -431,37 +415,6 @@ fn to_bad_ident_expr_report<'b>(
                 ]),
             ])
         }
-        PrivateTagNotUppercase(row, col) => {
-            let region = Region::from_row_col(row, col);
-
-            alloc.stack(vec![
-                alloc.reflow("I am trying to parse a private tag here:"),
-                alloc.region_with_subregion(surroundings, region),
-                alloc.concat(vec![
-                    alloc.reflow(r"But after the "),
-                    alloc.keyword("@"),
-                    alloc.reflow(r" symbol I found a lowercase letter. "),
-                    alloc.reflow(r"All tag names (global and private)"),
-                    alloc.reflow(r" must start with an uppercase letter, like "),
-                    alloc.parser_suggestion("@UUID"),
-                    alloc.reflow(" or "),
-                    alloc.parser_suggestion("@Secrets"),
-                    alloc.reflow("."),
-                ]),
-            ])
-        }
-
-        PrivateTagFieldAccess(row, col) => {
-            let region =
-                Region::from_rows_cols(surroundings.start_line, surroundings.start_col, row, col);
-            alloc.stack(vec![
-                alloc.reflow("I am very confused by this field access:"),
-                alloc.region_with_subregion(surroundings, region),
-                alloc.concat(vec![
-                    alloc.reflow(r"It looks like a record field access on a private tag.")
-                ]),
-            ])
-        }
 
         Underscore(row, col) => {
             let region =
@@ -475,28 +428,6 @@ fn to_bad_ident_expr_report<'b>(
             ])
         }
 
-        DoubleDot(row, col) => {
-            let region =
-                Region::from_rows_cols(surroundings.start_line, surroundings.start_col, row, col);
-            alloc.stack(vec![
-                alloc.reflow("I am very confused by these two dots in a row:"),
-                alloc.region_with_subregion(surroundings, region),
-                alloc.concat(vec![
-                    alloc.reflow(r"There always needs to be a name after a dot.")
-                ]),
-            ])
-        }
-
-        StrayAt(row, col) => {
-            let region =
-                Region::from_rows_cols(surroundings.start_line, surroundings.start_col, row, col);
-            alloc.stack(vec![
-                alloc.reflow("I am very confused by this @ symbol"),
-                alloc.region_with_subregion(surroundings, region),
-                alloc.concat(vec![alloc.reflow(r"I expected a private tag.")]),
-            ])
-        }
-
         BadPrivateTag(row, col) => {
             use BadIdentNext::*;
             match what_is_next(alloc.src_lines, row, col) {
@@ -579,22 +510,6 @@ fn to_bad_ident_pattern_report<'b>(
             ])
         }
 
-        PartStartsWithNumber(row, col) => {
-            let region = Region::from_row_col(row, col);
-
-            alloc.stack(vec![
-                alloc.reflow("I trying to parse a record field access here:"),
-                alloc.region_with_subregion(surroundings, region),
-                alloc.concat(vec![
-                    alloc.reflow("So I expect to see a lowercase letter next, like "),
-                    alloc.parser_suggestion(".name"),
-                    alloc.reflow(" or "),
-                    alloc.parser_suggestion(".height"),
-                    alloc.reflow("."),
-                ]),
-            ])
-        }
-
         WeirdAccessor(_row, _col) => alloc.stack(vec![
             alloc.reflow("I am very confused by this field access"),
             alloc.region(surroundings),
@@ -640,33 +555,6 @@ fn to_bad_ident_pattern_report<'b>(
                 ]),
             ])
         }
-        PrivateTagNotUppercase(row, col) => {
-            let region = Region::from_row_col(row, col);
-
-            alloc.stack(vec![
-                alloc.reflow("I am trying to parse a private tag here:"),
-                alloc.region_with_subregion(surroundings, region),
-                alloc.concat(vec![
-                    alloc.reflow(r"But after the "),
-                    alloc.keyword("@"),
-                    alloc.reflow(r" symbol I found a lowercase letter. "),
-                    alloc.reflow(r"All tag names (global and private)"),
-                    alloc.reflow(r" must start with an uppercase letter, like "),
-                    alloc.parser_suggestion("@UUID"),
-                    alloc.reflow(" or "),
-                    alloc.parser_suggestion("@Secrets"),
-                    alloc.reflow("."),
-                ]),
-            ])
-        }
-
-        PrivateTagFieldAccess(_row, _col) => alloc.stack(vec![
-            alloc.reflow("I am very confused by this field access:"),
-            alloc.region(surroundings),
-            alloc.concat(vec![
-                alloc.reflow(r"It looks like a record field access on a private tag.")
-            ]),
-        ]),
 
         Underscore(row, col) => {
             let region = Region::from_row_col(row, col - 1);

From 21f58b947aa70185b5c08a0ff890eac8ffcde34e Mon Sep 17 00:00:00 2001
From: Folkert <folkert@folkertdev.nl>
Date: Wed, 10 Mar 2021 23:04:28 +0100
Subject: [PATCH 47/74] shuffle error message handling

---
 compiler/parse/src/expr.rs | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/compiler/parse/src/expr.rs b/compiler/parse/src/expr.rs
index 1f69407eca..b99e386218 100644
--- a/compiler/parse/src/expr.rs
+++ b/compiler/parse/src/expr.rs
@@ -156,9 +156,9 @@ fn record_field_access_chain<'a>() -> impl Parser<'a, Vec<'a, &'a str>, EExpr<'a
 }
 
 fn record_field_access<'a>() -> impl Parser<'a, &'a str, EExpr<'a>> {
-    specialize(
-        |_, r, c| EExpr::Access(r, c),
-        skip_first!(ascii_char(b'.'), lowercase_ident()),
+    skip_first!(
+        word1(b'.', EExpr::Access),
+        specialize(|_, r, c| EExpr::Access(r, c), lowercase_ident())
     )
 }
 

From 37462d6ec651a550450813f87d5e0a86320290af Mon Sep 17 00:00:00 2001
From: Folkert <folkert@folkertdev.nl>
Date: Wed, 10 Mar 2021 23:06:47 +0100
Subject: [PATCH 48/74] use unit error type

---
 compiler/parse/src/ident.rs | 28 ++++++++++++++++++++++++----
 1 file changed, 24 insertions(+), 4 deletions(-)

diff --git a/compiler/parse/src/ident.rs b/compiler/parse/src/ident.rs
index 4c5b956363..05a7fb4bb9 100644
--- a/compiler/parse/src/ident.rs
+++ b/compiler/parse/src/ident.rs
@@ -179,12 +179,32 @@ pub fn lowercase_ident<'a>() -> impl Parser<'a, &'a str, SyntaxError<'a>> {
 /// * A module name
 /// * A type name
 /// * A global tag
-pub fn uppercase_ident<'a>() -> impl Parser<'a, &'a str, SyntaxError<'a>> {
-    global_tag_or_ident(|first_char| first_char.is_uppercase())
+pub fn uppercase_ident<'a>() -> impl Parser<'a, &'a str, ()> {
+    move |_, mut state: State<'a>| match chomp_uppercase_part(state.bytes) {
+        Err(progress) => Err((progress, (), state)),
+        Ok(ident) => {
+            let width = ident.len();
+            state.column += width as u16;
+            state.bytes = &state.bytes[width..];
+            Ok((MadeProgress, ident, state))
+        }
+    }
 }
 
-pub fn unqualified_ident<'a>() -> impl Parser<'a, &'a str, SyntaxError<'a>> {
-    global_tag_or_ident(|first_char| first_char.is_alphabetic())
+pub fn unqualified_ident<'a>() -> impl Parser<'a, &'a str, ()> {
+    move |_, mut state: State<'a>| match chomp_part(|c| c.is_alphabetic(), state.bytes) {
+        Err(progress) => Err((progress, (), state)),
+        Ok(ident) => {
+            if crate::keyword::KEYWORDS.iter().any(|kw| &ident == kw) {
+                Err((MadeProgress, (), state))
+            } else {
+                let width = ident.len();
+                state.column += width as u16;
+                state.bytes = &state.bytes[width..];
+                Ok((MadeProgress, ident, state))
+            }
+        }
+    }
 }
 
 pub fn join_module_parts<'a>(arena: &'a Bump, module_parts: &[&str]) -> &'a str {

From 30b47b95936df82b3063307692e1e47b596ceb99 Mon Sep 17 00:00:00 2001
From: Folkert <folkert@folkertdev.nl>
Date: Wed, 10 Mar 2021 23:08:12 +0100
Subject: [PATCH 49/74] use unit error type more

---
 compiler/parse/src/ident.rs | 121 +++++-------------------------------
 1 file changed, 15 insertions(+), 106 deletions(-)

diff --git a/compiler/parse/src/ident.rs b/compiler/parse/src/ident.rs
index 05a7fb4bb9..3413db0cac 100644
--- a/compiler/parse/src/ident.rs
+++ b/compiler/parse/src/ident.rs
@@ -61,117 +61,26 @@ impl<'a> Ident<'a> {
     }
 }
 
-fn chomp_identifier<'a, F>(pred: F, buffer: &[u8]) -> Result<&str, Progress>
-where
-    F: Fn(char) -> bool,
-{
-    use encode_unicode::CharExt;
-
-    let mut chomped = 0;
-
-    match char::from_utf8_slice_start(&buffer[chomped..]) {
-        Ok((ch, width)) if pred(ch) => {
-            chomped += width;
-        }
-        _ => {
-            // no parse
-            return Err(Progress::NoProgress);
-        }
-    }
-
-    while let Ok((ch, width)) = char::from_utf8_slice_start(&buffer[chomped..]) {
-        // After the first character, only these are allowed:
-        //
-        // * Unicode alphabetic chars - you might include `鹏` if that's clear to your readers
-        // * ASCII digits - e.g. `1` but not `¾`, both of which pass .is_numeric()
-        // * A ':' indicating the end of the field
-        if ch.is_alphabetic() || ch.is_ascii_digit() {
-            chomped += width;
-        } else {
-            // we're done
-            break;
-        }
-    }
-
-    let name = unsafe { std::str::from_utf8_unchecked(&buffer[..chomped]) };
-
-    Ok(name)
-}
-
-fn global_tag_or_ident<'a, F>(pred: F) -> impl Parser<'a, &'a str, SyntaxError<'a>>
-where
-    F: Fn(char) -> bool,
-{
-    move |arena, mut state: State<'a>| {
-        // pred will determine if this is a tag or ident (based on capitalization)
-        let (first_letter, bytes_parsed) = match peek_utf8_char(&state) {
-            Ok((first_letter, bytes_parsed)) => {
-                if !pred(first_letter) {
-                    return Err(unexpected(0, Attempting::RecordFieldLabel, state));
-                }
-
-                (first_letter, bytes_parsed)
-            }
-            Err(reason) => return state.fail(arena, NoProgress, reason),
-        };
-
-        let mut buf = String::with_capacity_in(1, arena);
-
-        buf.push(first_letter);
-
-        state = state.advance_without_indenting(bytes_parsed)?;
-
-        while !state.bytes.is_empty() {
-            match peek_utf8_char(&state) {
-                Ok((ch, bytes_parsed)) => {
-                    // After the first character, only these are allowed:
-                    //
-                    // * Unicode alphabetic chars - you might include `鹏` if that's clear to your readers
-                    // * ASCII digits - e.g. `1` but not `¾`, both of which pass .is_numeric()
-                    // * A ':' indicating the end of the field
-                    if ch.is_alphabetic() || ch.is_ascii_digit() {
-                        buf.push(ch);
-
-                        state = state.advance_without_indenting(bytes_parsed)?;
-                    } else {
-                        // This is the end of the field. We're done!
-                        break;
-                    }
-                }
-                Err(reason) => return state.fail(arena, MadeProgress, reason),
-            };
-        }
-
-        Ok((MadeProgress, buf.into_bump_str(), state))
-    }
-}
-
 /// This could be:
 ///
 /// * A record field, e.g. "email" in `.email` or in `email:`
 /// * A named pattern match, e.g. "foo" in `foo =` or `foo ->` or `\foo ->`
-pub fn lowercase_ident<'a>() -> impl Parser<'a, &'a str, SyntaxError<'a>> {
-    move |arena, state: State<'a>| {
-        let (progress, ident, state) =
-            global_tag_or_ident(|first_char| first_char.is_lowercase()).parse(arena, state)?;
-
-        // to parse a valid ident, progress must be made
-        debug_assert_eq!(progress, MadeProgress);
-
-        if (ident == keyword::IF)
-            || (ident == keyword::THEN)
-            || (ident == keyword::ELSE)
-            || (ident == keyword::WHEN)
-            || (ident == keyword::IS)
-            || (ident == keyword::AS)
-        {
-            // TODO Calculate the correct region based on state
-            let region = Region::zero();
-            Err((MadeProgress, SyntaxError::ReservedKeyword(region), state))
-        } else {
-            Ok((MadeProgress, ident, state))
+pub fn lowercase_ident<'a>() -> impl Parser<'a, &'a str, ()> {
+    debug!(
+        move |_, mut state: State<'a>| match chomp_lowercase_part(state.bytes) {
+            Err(progress) => Err((progress, (), state)),
+            Ok(ident) => {
+                if crate::keyword::KEYWORDS.iter().any(|kw| &ident == kw) {
+                    Err((MadeProgress, (), state))
+                } else {
+                    let width = ident.len();
+                    state.column += width as u16;
+                    state.bytes = &state.bytes[width..];
+                    Ok((MadeProgress, ident, state))
+                }
+            }
         }
-    }
+    )
 }
 
 /// This could be:

From 92cff4c32a869527a8e14962da37f19b19ee080f Mon Sep 17 00:00:00 2001
From: Folkert <folkert@folkertdev.nl>
Date: Thu, 11 Mar 2021 01:48:05 +0100
Subject: [PATCH 50/74] optimize type parser

---
 compiler/parse/src/ident.rs           | 144 ++++++++++++++------------
 compiler/parse/src/type_annotation.rs | 101 +-----------------
 2 files changed, 83 insertions(+), 162 deletions(-)

diff --git a/compiler/parse/src/ident.rs b/compiler/parse/src/ident.rs
index 3413db0cac..dc633c953a 100644
--- a/compiler/parse/src/ident.rs
+++ b/compiler/parse/src/ident.rs
@@ -1,14 +1,7 @@
-use crate::ast::Attempting;
-use crate::keyword;
 use crate::parser::Progress::{self, *};
-use crate::parser::{
-    peek_utf8_char, unexpected, BadInputError, Col, EExpr, ParseResult, Parser, Row, State,
-    SyntaxError,
-};
-use bumpalo::collections::string::String;
+use crate::parser::{BadInputError, Col, EExpr, ParseResult, Parser, Row, State};
 use bumpalo::collections::vec::Vec;
 use bumpalo::Bump;
-use roc_region::all::Region;
 
 /// The parser accepts all of these in any position where any one of them could
 /// appear. This way, canonicalization can give more helpful error messages like
@@ -66,21 +59,20 @@ impl<'a> Ident<'a> {
 /// * A record field, e.g. "email" in `.email` or in `email:`
 /// * A named pattern match, e.g. "foo" in `foo =` or `foo ->` or `\foo ->`
 pub fn lowercase_ident<'a>() -> impl Parser<'a, &'a str, ()> {
-    debug!(
-        move |_, mut state: State<'a>| match chomp_lowercase_part(state.bytes) {
-            Err(progress) => Err((progress, (), state)),
-            Ok(ident) => {
-                if crate::keyword::KEYWORDS.iter().any(|kw| &ident == kw) {
-                    Err((MadeProgress, (), state))
-                } else {
-                    let width = ident.len();
-                    state.column += width as u16;
-                    state.bytes = &state.bytes[width..];
-                    Ok((MadeProgress, ident, state))
+    move |_, state: State<'a>| match chomp_lowercase_part(state.bytes) {
+        Err(progress) => Err((progress, (), state)),
+        Ok(ident) => {
+            if crate::keyword::KEYWORDS.iter().any(|kw| &ident == kw) {
+                Err((MadeProgress, (), state))
+            } else {
+                let width = ident.len();
+                match state.advance_without_indenting_ee(width, |_, _| ()) {
+                    Ok(state) => Ok((MadeProgress, ident, state)),
+                    Err(bad) => Err(bad),
                 }
             }
         }
-    )
+    }
 }
 
 /// This could be:
@@ -89,51 +81,35 @@ pub fn lowercase_ident<'a>() -> impl Parser<'a, &'a str, ()> {
 /// * A type name
 /// * A global tag
 pub fn uppercase_ident<'a>() -> impl Parser<'a, &'a str, ()> {
-    move |_, mut state: State<'a>| match chomp_uppercase_part(state.bytes) {
+    move |_, state: State<'a>| match chomp_uppercase_part(state.bytes) {
         Err(progress) => Err((progress, (), state)),
         Ok(ident) => {
             let width = ident.len();
-            state.column += width as u16;
-            state.bytes = &state.bytes[width..];
-            Ok((MadeProgress, ident, state))
+            match state.advance_without_indenting_ee(width, |_, _| ()) {
+                Ok(state) => Ok((MadeProgress, ident, state)),
+                Err(bad) => Err(bad),
+            }
         }
     }
 }
 
 pub fn unqualified_ident<'a>() -> impl Parser<'a, &'a str, ()> {
-    move |_, mut state: State<'a>| match chomp_part(|c| c.is_alphabetic(), state.bytes) {
+    move |_, state: State<'a>| match chomp_part(|c| c.is_alphabetic(), state.bytes) {
         Err(progress) => Err((progress, (), state)),
         Ok(ident) => {
             if crate::keyword::KEYWORDS.iter().any(|kw| &ident == kw) {
                 Err((MadeProgress, (), state))
             } else {
                 let width = ident.len();
-                state.column += width as u16;
-                state.bytes = &state.bytes[width..];
-                Ok((MadeProgress, ident, state))
+                match state.advance_without_indenting_ee(width, |_, _| ()) {
+                    Ok(state) => Ok((MadeProgress, ident, state)),
+                    Err(bad) => Err(bad),
+                }
             }
         }
     }
 }
 
-pub fn join_module_parts<'a>(arena: &'a Bump, module_parts: &[&str]) -> &'a str {
-    let capacity = module_parts.len() * 3; // Module parts tend to be 3+ characters.
-    let mut buf = String::with_capacity_in(capacity, arena);
-    let mut any_parts_added = false;
-
-    for part in module_parts {
-        if any_parts_added {
-            buf.push('.');
-        } else {
-            any_parts_added = true;
-        }
-
-        buf.push_str(part);
-    }
-
-    buf.into_bump_str()
-}
-
 macro_rules! advance_state {
     ($state:expr, $n:expr) => {
         $state.advance_without_indenting_ee($n, |r, c| {
@@ -185,30 +161,26 @@ fn malformed_identifier<'a>(
     _arena: &'a Bump,
     mut state: State<'a>,
 ) -> ParseResult<'a, Ident<'a>, EExpr<'a>> {
+    use encode_unicode::CharExt;
     // skip forward to the next non-identifier character
-    while !state.bytes.is_empty() {
-        match peek_utf8_char(&state) {
-            Ok((ch, bytes_parsed)) => {
-                // We can't use ch.is_alphanumeric() here because that passes for
-                // things that are "numeric" but not ASCII digits, like `¾`
-                if ch == '.' || ch == '_' || ch.is_alphabetic() || ch.is_ascii_digit() {
-                    state = state.advance_without_indenting_ee(bytes_parsed, |r, c| {
-                        EExpr::Space(crate::parser::BadInputError::LineTooLong, r, c)
-                    })?;
-                    continue;
-                } else {
-                    break;
-                }
-            }
-            Err(_reason) => {
-                break;
-            }
+    let mut chomped = 0;
+    while let Ok((ch, width)) = char::from_utf8_slice_start(&state.bytes[chomped..]) {
+        // We can't use ch.is_alphanumeric() here because that passes for
+        // things that are "numeric" but not ASCII digits, like `¾`
+        if ch == '.' || ch == '_' || ch.is_alphabetic() || ch.is_ascii_digit() {
+            chomped += width;
+            continue;
+        } else {
+            break;
         }
     }
 
-    let parsed = &initial_bytes[..(initial_bytes.len() - state.bytes.len())];
+    let delta = initial_bytes.len() - state.bytes.len();
+    let parsed_str = unsafe { std::str::from_utf8_unchecked(&initial_bytes[..chomped + delta]) };
 
-    let parsed_str = unsafe { std::str::from_utf8_unchecked(parsed) };
+    state = state.advance_without_indenting_ee(chomped, |r, c| {
+        EExpr::Space(crate::parser::BadInputError::LineTooLong, r, c)
+    })?;
 
     Ok((MadeProgress, Ident::Malformed(parsed_str, problem), state))
 }
@@ -240,7 +212,6 @@ fn chomp_part<F>(leading_is_good: F, buffer: &[u8]) -> Result<&str, Progress>
 where
     F: Fn(char) -> bool,
 {
-    // assumes the leading `.` has been chomped already
     use encode_unicode::CharExt;
 
     let mut chomped = 0;
@@ -455,6 +426,47 @@ fn chomp_module_chain<'a>(buffer: &'a [u8]) -> Result<u16, Progress> {
     }
 }
 
+pub fn concrete_type<'a>() -> impl Parser<'a, (&'a str, &'a str), ()> {
+    move |_, state: State<'a>| match chomp_concrete_type(state.bytes) {
+        Err(progress) => Err((progress, (), state)),
+        Ok((module_name, type_name, width)) => {
+            match state.advance_without_indenting_ee(width, |_, _| ()) {
+                Ok(state) => Ok((MadeProgress, (module_name, type_name), state)),
+                Err(bad) => Err(bad),
+            }
+        }
+    }
+}
+
+// parse a type name like `Result` or `Result.Result`
+fn chomp_concrete_type<'a>(buffer: &'a [u8]) -> Result<(&'a str, &'a str, usize), Progress> {
+    let first = crate::ident::chomp_uppercase_part(buffer)?;
+
+    if let Some(b'.') = buffer.get(first.len()) {
+        match crate::ident::chomp_module_chain(&buffer[first.len()..]) {
+            Err(_) => Err(MadeProgress),
+            Ok(rest) => {
+                let width = first.len() + rest as usize;
+                let slice = &buffer[..width];
+
+                match slice.iter().rev().position(|c| *c == b'.') {
+                    None => Ok(("", first, first.len())),
+                    Some(rev_index) => {
+                        let index = slice.len() - rev_index;
+                        let module_name =
+                            unsafe { std::str::from_utf8_unchecked(&slice[..index - 1]) };
+                        let type_name = unsafe { std::str::from_utf8_unchecked(&slice[index..]) };
+
+                        Ok((module_name, type_name, width))
+                    }
+                }
+            }
+        }
+    } else {
+        Ok(("", first, first.len()))
+    }
+}
+
 fn chomp_access_chain<'a>(buffer: &'a [u8], parts: &mut Vec<'a, &'a str>) -> Result<u16, u16> {
     let mut chomped = 0;
 
diff --git a/compiler/parse/src/type_annotation.rs b/compiler/parse/src/type_annotation.rs
index 5f7b6fb5f1..116e345f0e 100644
--- a/compiler/parse/src/type_annotation.rs
+++ b/compiler/parse/src/type_annotation.rs
@@ -1,6 +1,5 @@
 use crate::ast::{AssignedField, Tag, TypeAnnotation};
 use crate::blankspace::{space0_around_ee, space0_before_e, space0_e};
-use crate::ident::join_module_parts;
 use crate::keyword;
 use crate::parser::{
     allocated, backtrackable, not_e, optional, peek_utf8_char_e, specialize, specialize_ref, word1,
@@ -517,102 +516,12 @@ fn expression<'a>(min_indent: u16) -> impl Parser<'a, Located<TypeAnnotation<'a>
 
 fn parse_concrete_type<'a>(
     arena: &'a Bump,
-    mut state: State<'a>,
+    state: State<'a>,
 ) -> ParseResult<'a, TypeAnnotation<'a>, TApply> {
-    let mut part_buf = String::new_in(arena); // The current "part" (parts are dot-separated.)
-    let mut parts: Vec<&'a str> = Vec::new_in(arena);
-
-    // Qualified types must start with a capitalized letter.
-    match peek_utf8_char_e(&state, TApply::StartNotUppercase, TApply::Space) {
-        Ok((first_letter, bytes_parsed)) => {
-            if first_letter.is_alphabetic() && first_letter.is_uppercase() {
-                part_buf.push(first_letter);
-            } else {
-                let problem = TApply::StartNotUppercase(state.line, state.column + 1);
-                return Err((NoProgress, problem, state));
-            }
-
-            state = state.advance_without_indenting_e(bytes_parsed, TApply::Space)?;
-        }
-        Err(reason) => return Err((NoProgress, reason, state)),
-    }
-
-    while !state.bytes.is_empty() {
-        match peek_utf8_char_e(&state, TApply::End, TApply::Space) {
-            Ok((ch, bytes_parsed)) => {
-                // After the first character, only these are allowed:
-                //
-                // * Unicode alphabetic chars - you might name a variable `鹏` if that's clear to your readers
-                // * ASCII digits - e.g. `1` but not `¾`, both of which pass .is_numeric()
-                // * A dot ('.')
-                if ch.is_alphabetic() {
-                    if part_buf.is_empty() && !ch.is_uppercase() {
-                        // Each part must begin with a capital letter.
-                        return Err((
-                            MadeProgress,
-                            TApply::StartNotUppercase(state.line, state.column),
-                            state,
-                        ));
-                    }
-
-                    part_buf.push(ch);
-                } else if ch.is_ascii_digit() {
-                    // Parts may not start with numbers!
-                    if part_buf.is_empty() {
-                        return Err((
-                            MadeProgress,
-                            TApply::StartIsNumber(state.line, state.column),
-                            state,
-                        ));
-                    }
-
-                    part_buf.push(ch);
-                } else if ch == '.' {
-                    // Having two consecutive dots is an error.
-                    if part_buf.is_empty() {
-                        return Err((
-                            MadeProgress,
-                            TApply::DoubleDot(state.line, state.column),
-                            state,
-                        ));
-                    }
-
-                    parts.push(part_buf.into_bump_str());
-
-                    // Now that we've recorded the contents of the current buffer, reset it.
-                    part_buf = String::new_in(arena);
-                } else {
-                    // This must be the end of the type. We're done!
-                    break;
-                }
-
-                state = state.advance_without_indenting_e(bytes_parsed, TApply::Space)?;
-            }
-            Err(reason) => {
-                return Err((MadeProgress, reason, state));
-            }
-        }
-    }
-
-    if part_buf.is_empty() {
-        // We probably had a trailing dot, e.g. `Foo.bar.` - this is malformed!
-        //
-        // This condition might also occur if we encounter a malformed accessor like `.|`
-        //
-        // If we made it this far and don't have a next_char, then necessarily
-        // we have consumed a '.' char previously.
-        return Err((
-            MadeProgress,
-            TApply::TrailingDot(state.line, state.column),
-            state,
-        ));
-    }
-
-    let answer = TypeAnnotation::Apply(
-        join_module_parts(arena, parts.into_bump_slice()),
-        part_buf.into_bump_str(),
-        &[],
-    );
+    let (_, (module_name, type_name), state) =
+        specialize(|_, r, c| TApply::End(r, c), crate::ident::concrete_type())
+            .parse(arena, state)?;
+    let answer = TypeAnnotation::Apply(module_name, type_name, &[]);
 
     Ok((MadeProgress, answer, state))
 }

From e214674016b4c75c742cda0fa54219e2cd5d017c Mon Sep 17 00:00:00 2001
From: Folkert <folkert@folkertdev.nl>
Date: Thu, 11 Mar 2021 16:37:42 +0100
Subject: [PATCH 51/74] cleanup blankspace function usage

---
 compiler/parse/src/blankspace.rs   | 16 ++++----
 compiler/parse/src/expr.rs         | 61 ++++++++++--------------------
 compiler/parse/src/module.rs       | 19 ++++++++--
 compiler/parse/src/test_helpers.rs | 10 ++---
 editor/src/lang/expr.rs            | 11 ++----
 5 files changed, 51 insertions(+), 66 deletions(-)

diff --git a/compiler/parse/src/blankspace.rs b/compiler/parse/src/blankspace.rs
index 93e6653a3b..0bb8ac2fb0 100644
--- a/compiler/parse/src/blankspace.rs
+++ b/compiler/parse/src/blankspace.rs
@@ -15,7 +15,7 @@ use roc_region::all::{Located, Region};
 /// Returns a Located<Expr> where the location is around the Expr, ignoring the spaces.
 /// If any newlines or comments were found, the Expr will be wrapped in a SpaceBefore and/or
 /// SpaceAfter as appropriate.
-pub fn space0_around<'a, P, S>(
+fn space0_around<'a, P, S>(
     parser: P,
     min_indent: u16,
 ) -> impl Parser<'a, Located<S>, SyntaxError<'a>>
@@ -119,7 +119,7 @@ where
 /// Returns a Located<Expr> where the location is around the Expr, ignoring the spaces.
 /// If any newlines or comments were found, the Expr will be wrapped in a SpaceBefore and/or
 /// SpaceAfter as appropriate.
-pub fn space1_around<'a, P, S>(
+fn space1_around<'a, P, S>(
     parser: P,
     min_indent: u16,
 ) -> impl Parser<'a, Located<S>, SyntaxError<'a>>
@@ -160,7 +160,7 @@ where
 /// Parses the given expression with 0 or more (spaces/comments/newlines) before it.
 /// Returns a Located<Expr> where the location is around the Expr, ignoring the spaces.
 /// The Expr will be wrapped in a SpaceBefore if there were any newlines or comments found.
-pub fn space0_before<'a, P, S>(
+fn space0_before<'a, P, S>(
     parser: P,
     min_indent: u16,
 ) -> impl Parser<'a, Located<S>, SyntaxError<'a>>
@@ -241,7 +241,7 @@ where
 /// Parses the given expression with 1 or more (spaces/comments/newlines) before it.
 /// Returns a Located<Expr> where the location is around the Expr, ignoring the spaces.
 /// The Expr will be wrapped in a SpaceBefore if there were any newlines or comments found.
-pub fn space1_before<'a, P, S>(
+fn space1_before<'a, P, S>(
     parser: P,
     min_indent: u16,
 ) -> impl Parser<'a, Located<S>, SyntaxError<'a>>
@@ -268,7 +268,7 @@ where
 /// Parses the given expression with 0 or more (spaces/comments/newlines) after it.
 /// Returns a Located<Expr> where the location is around the Expr, ignoring the spaces.
 /// The Expr will be wrapped in a SpaceAfter if there were any newlines or comments found.
-pub fn space0_after<'a, P, S>(
+fn space0_after<'a, P, S>(
     parser: P,
     min_indent: u16,
 ) -> impl Parser<'a, Located<S>, SyntaxError<'a>>
@@ -295,7 +295,7 @@ where
 /// Parses the given expression with 1 or more (spaces/comments/newlines) after it.
 /// Returns a Located<Expr> where the location is around the Expr, ignoring the spaces.
 /// The Expr will be wrapped in a SpaceAfter if there were any newlines or comments found.
-pub fn space1_after<'a, P, S>(
+fn space1_after<'a, P, S>(
     parser: P,
     min_indent: u16,
 ) -> impl Parser<'a, Located<S>, SyntaxError<'a>>
@@ -320,7 +320,7 @@ where
 }
 
 /// Zero or more (spaces/comments/newlines).
-pub fn space0<'a>(min_indent: u16) -> impl Parser<'a, &'a [CommentOrNewline<'a>], SyntaxError<'a>> {
+fn space0<'a>(min_indent: u16) -> impl Parser<'a, &'a [CommentOrNewline<'a>], SyntaxError<'a>> {
     spaces(false, min_indent)
 }
 
@@ -360,7 +360,7 @@ where
 }
 
 /// One or more (spaces/comments/newlines).
-pub fn space1<'a>(min_indent: u16) -> impl Parser<'a, &'a [CommentOrNewline<'a>], SyntaxError<'a>> {
+fn space1<'a>(min_indent: u16) -> impl Parser<'a, &'a [CommentOrNewline<'a>], SyntaxError<'a>> {
     // TODO try benchmarking a short-circuit for the typical case: see if there is
     // exactly one space followed by char that isn't [' ', '\n', or '#'], and
     // if so, return empty slice. The case where there's exactly 1 space should
diff --git a/compiler/parse/src/expr.rs b/compiler/parse/src/expr.rs
index b99e386218..db26b10ebe 100644
--- a/compiler/parse/src/expr.rs
+++ b/compiler/parse/src/expr.rs
@@ -20,6 +20,24 @@ use roc_region::all::{Located, Region};
 
 use crate::parser::Progress::{self, *};
 
+pub fn test_parse_expr<'a>(
+    min_indent: u16,
+    arena: &'a bumpalo::Bump,
+    state: State<'a>,
+) -> Result<(Located<Expr<'a>>, State<'a>), EExpr<'a>> {
+    let parser = space0_before_e(
+        loc!(|a, s| parse_expr_help(min_indent, a, s)),
+        min_indent,
+        EExpr::Space,
+        EExpr::IndentStart,
+    );
+
+    match parser.parse(arena, state) {
+        Ok((_, expression, state)) => Ok((expression, state)),
+        Err((_, fail, _)) => Err(fail),
+    }
+}
+
 // public for testing purposes
 pub fn expr<'a>(min_indent: u16) -> impl Parser<'a, Expr<'a>, SyntaxError<'a>> {
     // Recursive parsers must not directly invoke functions which return (impl Parser),
@@ -718,47 +736,6 @@ fn assigned_expr_field_to_pattern_help<'a>(
     })
 }
 
-/// A def beginning with a parenthetical pattern, for example:
-///
-/// (UserId userId) = ...
-///
-/// Note: Parenthetical patterns are a shorthand convenience, and may not have type annotations.
-/// It would be too weird to parse; imagine `(UserId userId) : ...` above `(UserId userId) = ...`
-/// !!!! THIS IS NOT USED !!!!
-// fn loc_parenthetical_def<'a>(min_indent: u16) -> impl Parser<'a, Located<Expr<'a>>> {
-//     move |arena, state| {
-//         let (loc_tuple, state) = loc!(and!(
-//             space0_after(
-//                 between!(
-//                     ascii_char(b'('),
-//                     space0_around(loc_pattern(min_indent), min_indent),
-//                     ascii_char(b')')
-//                 ),
-//                 min_indent,
-//             ),
-//             equals_with_indent()
-//         ))
-//         .parse(arena, state)?;
-
-//         let region = loc_tuple.region;
-//         let (loc_first_pattern, equals_sign_indent) = loc_tuple.value;
-
-//         // Continue parsing the expression as a Def.
-//         let (spaces_after_equals, state) = space0(min_indent).parse(arena, state)?;
-//         let (value, state) = parse_def_expr(
-//             region.start_col,
-//             min_indent,
-//             equals_sign_indent,
-//             arena,
-//             state,
-//             loc_first_pattern,
-//             spaces_after_equals,
-//         )?;
-
-//         Ok((Located { value, region }, state))
-//     }
-// }
-
 fn parse_defs_help<'a>(
     min_indent: u16,
 ) -> impl Parser<'a, Vec<'a, &'a Located<Def<'a>>>, EExpr<'a>> {
@@ -795,7 +772,7 @@ pub fn def<'a>(min_indent: u16) -> impl Parser<'a, Def<'a>, SyntaxError<'a>> {
     specialize(|e, _, _| SyntaxError::Expr(e), def_help(min_indent))
 }
 
-fn def_help<'a>(min_indent: u16) -> impl Parser<'a, Def<'a>, EExpr<'a>> {
+pub fn def_help<'a>(min_indent: u16) -> impl Parser<'a, Def<'a>, EExpr<'a>> {
     let indented_more = min_indent + 1;
 
     enum DefKind {
diff --git a/compiler/parse/src/module.rs b/compiler/parse/src/module.rs
index 32d2fb2919..0068ae6933 100644
--- a/compiler/parse/src/module.rs
+++ b/compiler/parse/src/module.rs
@@ -1,6 +1,5 @@
 use crate::ast::{CommentOrNewline, Def, Module};
-use crate::blankspace::{space0_around, space0_before_e, space0_e};
-use crate::expr::def;
+use crate::blankspace::{space0_before_e, space0_e};
 use crate::header::{
     package_entry, package_name, package_or_path, AppHeader, Effects, ExposesEntry, ImportsEntry,
     InterfaceHeader, ModuleName, PackageEntry, PlatformHeader, To, TypedIdent,
@@ -252,8 +251,22 @@ fn platform_header<'a>() -> impl Parser<'a, PlatformHeader<'a>, EHeader<'a>> {
 
 #[inline(always)]
 pub fn module_defs<'a>() -> impl Parser<'a, Vec<'a, Located<Def<'a>>>, SyntaxError<'a>> {
+    use crate::parser::EExpr;
     // force that we pare until the end of the input
-    skip_second!(zero_or_more!(space0_around(loc!(def(0)), 0)), end_of_file())
+    let min_indent = 0;
+    skip_second!(
+        specialize(
+            |e, _, _| SyntaxError::Expr(e),
+            zero_or_more!(crate::blankspace::space0_around_ee(
+                loc!(crate::expr::def_help(min_indent)),
+                min_indent,
+                EExpr::Space,
+                EExpr::IndentStart,
+                EExpr::IndentEnd,
+            ))
+        ),
+        end_of_file()
+    )
 }
 #[derive(Debug)]
 struct ProvidesTo<'a> {
diff --git a/compiler/parse/src/test_helpers.rs b/compiler/parse/src/test_helpers.rs
index 7fce100612..b5c6e226d8 100644
--- a/compiler/parse/src/test_helpers.rs
+++ b/compiler/parse/src/test_helpers.rs
@@ -1,5 +1,4 @@
 use crate::ast;
-use crate::blankspace::space0_before;
 use crate::expr::expr;
 use crate::module::module_defs;
 use crate::parser::{loc, Parser, State, SyntaxError};
@@ -32,10 +31,9 @@ pub fn parse_loc_with<'a>(
     input: &'a str,
 ) -> Result<Located<ast::Expr<'a>>, SyntaxError<'a>> {
     let state = State::new_in(arena, input.trim().as_bytes());
-    let parser = space0_before(loc(expr(0)), 0);
-    let answer = parser.parse(&arena, state);
 
-    answer
-        .map(|(_, loc_expr, _)| loc_expr)
-        .map_err(|(_, fail, _)| fail)
+    match crate::expr::test_parse_expr(0, arena, state) {
+        Ok((loc_expr, _state)) => Ok(loc_expr),
+        Err(fail) => Err(SyntaxError::Expr(fail)),
+    }
 }
diff --git a/editor/src/lang/expr.rs b/editor/src/lang/expr.rs
index 410009bc2e..58243df0ce 100644
--- a/editor/src/lang/expr.rs
+++ b/editor/src/lang/expr.rs
@@ -18,7 +18,6 @@ use roc_module::operator::CalledVia;
 use roc_module::symbol::{IdentIds, ModuleId, ModuleIds, Symbol};
 use roc_parse::ast;
 use roc_parse::ast::StrLiteral;
-use roc_parse::blankspace::space0_before;
 use roc_parse::expr::expr;
 use roc_parse::parser::{loc, Parser, State, SyntaxError};
 use roc_problem::can::{Problem, RuntimeError};
@@ -236,13 +235,11 @@ pub fn str_to_expr2<'a>(
     region: Region,
 ) -> Result<(Expr2, self::Output), SyntaxError<'a>> {
     let state = State::new_in(arena, input.trim().as_bytes());
-    let parser = space0_before(loc(expr(0)), 0);
-    let parse_res = parser.parse(&arena, state);
 
-    parse_res
-        .map(|(_, loc_expr, _)| arena.alloc(loc_expr.value))
-        .map(|loc_expr_val_ref| to_expr2(env, scope, loc_expr_val_ref, region))
-        .map_err(|(_, fail, _)| fail)
+    match roc_parse::expr::test_parse_expr(0, arena, state) {
+        Ok((loc_expr, _state)) => Ok(to_expr2(env, scope, arena.alloc(loc_expr.value), region)),
+        Err(fail) => Err(SyntaxError::Expr(fail)),
+    }
 }
 
 pub fn to_expr2<'a>(

From b4b77add087992143141cacd50c0120ff8b51a68 Mon Sep 17 00:00:00 2001
From: Folkert <folkert@folkertdev.nl>
Date: Thu, 11 Mar 2021 16:40:01 +0100
Subject: [PATCH 52/74] cleanup

---
 compiler/parse/src/blankspace.rs | 234 +------------------------------
 1 file changed, 3 insertions(+), 231 deletions(-)

diff --git a/compiler/parse/src/blankspace.rs b/compiler/parse/src/blankspace.rs
index 0bb8ac2fb0..ce9f6d45eb 100644
--- a/compiler/parse/src/blankspace.rs
+++ b/compiler/parse/src/blankspace.rs
@@ -1,64 +1,15 @@
 use crate::ast::CommentOrNewline::{self, *};
 use crate::ast::{Attempting, Spaceable};
 use crate::parser::{
-    self, and, ascii_char, ascii_string, backtrackable, bad_input_to_syntax_error, optional,
-    parse_utf8, peek_utf8_char, then, unexpected, unexpected_eof, BadInputError, Col, Parser,
+    self, and, ascii_char, ascii_string, optional, parse_utf8, peek_utf8_char, then, unexpected,
+    unexpected_eof, BadInputError, Col, Parser,
     Progress::{self, *},
     Row, State, SyntaxError,
 };
 use bumpalo::collections::string::String;
 use bumpalo::collections::vec::Vec;
 use bumpalo::Bump;
-use roc_region::all::{Located, Region};
-
-/// Parses the given expression with 0 or more (spaces/comments/newlines) before and/or after it.
-/// Returns a Located<Expr> where the location is around the Expr, ignoring the spaces.
-/// If any newlines or comments were found, the Expr will be wrapped in a SpaceBefore and/or
-/// SpaceAfter as appropriate.
-fn space0_around<'a, P, S>(
-    parser: P,
-    min_indent: u16,
-) -> impl Parser<'a, Located<S>, SyntaxError<'a>>
-where
-    S: Spaceable<'a>,
-    S: 'a,
-    S: Sized,
-    P: Parser<'a, Located<S>, SyntaxError<'a>>,
-    P: 'a,
-{
-    parser::map_with_arena(
-        and(space0(min_indent), and(parser, space0(min_indent))),
-        move |arena: &'a Bump,
-              tuples: (
-            &'a [CommentOrNewline<'a>],
-            (Located<S>, &'a [CommentOrNewline<'a>]),
-        )| {
-            let (spaces_before, (loc_val, spaces_after)) = tuples;
-
-            if spaces_before.is_empty() {
-                if spaces_after.is_empty() {
-                    loc_val
-                } else {
-                    arena
-                        .alloc(loc_val.value)
-                        .with_spaces_after(spaces_after, loc_val.region)
-                }
-            } else if spaces_after.is_empty() {
-                arena
-                    .alloc(loc_val.value)
-                    .with_spaces_before(spaces_before, loc_val.region)
-            } else {
-                let wrapped_expr = arena
-                    .alloc(loc_val.value)
-                    .with_spaces_after(spaces_after, loc_val.region);
-
-                arena
-                    .alloc(wrapped_expr.value)
-                    .with_spaces_before(spaces_before, wrapped_expr.region)
-            }
-        },
-    )
-}
+use roc_region::all::Located;
 
 pub fn space0_around_ee<'a, P, S, E>(
     parser: P,
@@ -114,76 +65,6 @@ where
     )
 }
 
-/// Parses the given expression with 1 or more (spaces/comments/newlines) before it,
-/// and also 1 or more spaces after it.
-/// Returns a Located<Expr> where the location is around the Expr, ignoring the spaces.
-/// If any newlines or comments were found, the Expr will be wrapped in a SpaceBefore and/or
-/// SpaceAfter as appropriate.
-fn space1_around<'a, P, S>(
-    parser: P,
-    min_indent: u16,
-) -> impl Parser<'a, Located<S>, SyntaxError<'a>>
-where
-    S: Spaceable<'a>,
-    S: 'a,
-    P: Parser<'a, Located<S>, SyntaxError<'a>>,
-    P: 'a,
-{
-    parser::map_with_arena(
-        and(space1(min_indent), and(parser, space1(min_indent))),
-        |arena, (spaces_before, (loc_expr, spaces_after))| {
-            if spaces_before.is_empty() {
-                if spaces_after.is_empty() {
-                    loc_expr
-                } else {
-                    arena
-                        .alloc(loc_expr.value)
-                        .with_spaces_after(spaces_after, loc_expr.region)
-                }
-            } else if spaces_after.is_empty() {
-                arena
-                    .alloc(loc_expr.value)
-                    .with_spaces_before(spaces_before, loc_expr.region)
-            } else {
-                let loc_wrapped_expr = arena
-                    .alloc(loc_expr.value)
-                    .with_spaces_after(spaces_after, loc_expr.region);
-
-                arena
-                    .alloc(loc_wrapped_expr.value)
-                    .with_spaces_before(spaces_before, loc_wrapped_expr.region)
-            }
-        },
-    )
-}
-
-/// Parses the given expression with 0 or more (spaces/comments/newlines) before it.
-/// Returns a Located<Expr> where the location is around the Expr, ignoring the spaces.
-/// The Expr will be wrapped in a SpaceBefore if there were any newlines or comments found.
-fn space0_before<'a, P, S>(
-    parser: P,
-    min_indent: u16,
-) -> impl Parser<'a, Located<S>, SyntaxError<'a>>
-where
-    S: Spaceable<'a>,
-    S: 'a,
-    P: Parser<'a, Located<S>, SyntaxError<'a>>,
-    P: 'a,
-{
-    parser::map_with_arena(
-        and!(space0(min_indent), parser),
-        |arena: &'a Bump, (space_list, loc_expr): (&'a [CommentOrNewline<'a>], Located<S>)| {
-            if space_list.is_empty() {
-                loc_expr
-            } else {
-                arena
-                    .alloc(loc_expr.value)
-                    .with_spaces_before(space_list, loc_expr.region)
-            }
-        },
-    )
-}
-
 pub fn space0_before_e<'a, P, S, E>(
     parser: P,
     min_indent: u16,
@@ -238,92 +119,6 @@ where
     )
 }
 
-/// Parses the given expression with 1 or more (spaces/comments/newlines) before it.
-/// Returns a Located<Expr> where the location is around the Expr, ignoring the spaces.
-/// The Expr will be wrapped in a SpaceBefore if there were any newlines or comments found.
-fn space1_before<'a, P, S>(
-    parser: P,
-    min_indent: u16,
-) -> impl Parser<'a, Located<S>, SyntaxError<'a>>
-where
-    S: Spaceable<'a>,
-    S: 'a,
-    P: Parser<'a, Located<S>, SyntaxError<'a>>,
-    P: 'a,
-{
-    parser::map_with_arena(
-        and!(backtrackable(space1(min_indent)), parser),
-        |arena, (space_list, loc_expr)| {
-            if space_list.is_empty() {
-                loc_expr
-            } else {
-                arena
-                    .alloc(loc_expr.value)
-                    .with_spaces_before(space_list, loc_expr.region)
-            }
-        },
-    )
-}
-
-/// Parses the given expression with 0 or more (spaces/comments/newlines) after it.
-/// Returns a Located<Expr> where the location is around the Expr, ignoring the spaces.
-/// The Expr will be wrapped in a SpaceAfter if there were any newlines or comments found.
-fn space0_after<'a, P, S>(
-    parser: P,
-    min_indent: u16,
-) -> impl Parser<'a, Located<S>, SyntaxError<'a>>
-where
-    S: Spaceable<'a>,
-    S: 'a,
-    P: Parser<'a, Located<S>, SyntaxError<'a>>,
-    P: 'a,
-{
-    parser::map_with_arena(
-        and!(parser, space0(min_indent)),
-        |arena, (loc_expr, space_list)| {
-            if space_list.is_empty() {
-                loc_expr
-            } else {
-                arena
-                    .alloc(loc_expr.value)
-                    .with_spaces_after(space_list, loc_expr.region)
-            }
-        },
-    )
-}
-
-/// Parses the given expression with 1 or more (spaces/comments/newlines) after it.
-/// Returns a Located<Expr> where the location is around the Expr, ignoring the spaces.
-/// The Expr will be wrapped in a SpaceAfter if there were any newlines or comments found.
-fn space1_after<'a, P, S>(
-    parser: P,
-    min_indent: u16,
-) -> impl Parser<'a, Located<S>, SyntaxError<'a>>
-where
-    S: Spaceable<'a>,
-    S: 'a,
-    P: Parser<'a, Located<S>, SyntaxError<'a>>,
-    P: 'a,
-{
-    parser::map_with_arena(
-        and!(parser, space1(min_indent)),
-        |arena, (loc_expr, space_list)| {
-            if space_list.is_empty() {
-                loc_expr
-            } else {
-                arena
-                    .alloc(loc_expr.value)
-                    .with_spaces_after(space_list, loc_expr.region)
-            }
-        },
-    )
-}
-
-/// Zero or more (spaces/comments/newlines).
-fn space0<'a>(min_indent: u16) -> impl Parser<'a, &'a [CommentOrNewline<'a>], SyntaxError<'a>> {
-    spaces(false, min_indent)
-}
-
 pub fn space0_e<'a, E>(
     min_indent: u16,
     space_problem: fn(BadInputError, Row, Col) -> E,
@@ -359,15 +154,6 @@ where
     }
 }
 
-/// One or more (spaces/comments/newlines).
-fn space1<'a>(min_indent: u16) -> impl Parser<'a, &'a [CommentOrNewline<'a>], SyntaxError<'a>> {
-    // TODO try benchmarking a short-circuit for the typical case: see if there is
-    // exactly one space followed by char that isn't [' ', '\n', or '#'], and
-    // if so, return empty slice. The case where there's exactly 1 space should
-    // be by far the most common.
-    spaces(true, min_indent)
-}
-
 #[derive(Debug, Clone, Copy)]
 enum LineState {
     Normal,
@@ -512,20 +298,6 @@ pub fn spaces_exactly_e<'a>(spaces_expected: u16) -> impl Parser<'a, (), parser:
     }
 }
 
-#[inline(always)]
-fn spaces<'a>(
-    require_at_least_one: bool,
-    min_indent: u16,
-) -> impl Parser<'a, &'a [CommentOrNewline<'a>], SyntaxError<'a>> {
-    spaces_help(
-        require_at_least_one,
-        min_indent,
-        bad_input_to_syntax_error,
-        |_, _| SyntaxError::OutdentedTooFar,
-        |_, _| SyntaxError::Eof(Region::zero()),
-    )
-}
-
 #[inline(always)]
 fn spaces_help<'a, E>(
     require_at_least_one: bool,

From 3e554cb21f64eac2913e942e76ec5a096cbe905e Mon Sep 17 00:00:00 2001
From: Folkert <folkert@folkertdev.nl>
Date: Thu, 11 Mar 2021 21:21:00 +0100
Subject: [PATCH 53/74] cleanup

---
 compiler/fmt/tests/test_fmt.rs             |  12 +--
 compiler/parse/src/blankspace.rs           |  81 +++++++++++----
 compiler/parse/src/expr.rs                 |  40 +++++---
 compiler/parse/src/ident.rs                |  34 ++++---
 compiler/parse/src/parser.rs               |   1 +
 compiler/parse/src/test_helpers.rs         |   3 +-
 compiler/parse/src/type_annotation.rs      |  32 +++++-
 compiler/reporting/src/error/parse.rs      |  27 +++++
 compiler/reporting/tests/helpers/mod.rs    |  12 +--
 compiler/reporting/tests/test_reporting.rs | 112 ++++++++++++---------
 10 files changed, 237 insertions(+), 117 deletions(-)

diff --git a/compiler/fmt/tests/test_fmt.rs b/compiler/fmt/tests/test_fmt.rs
index d2faf53847..13ade561a9 100644
--- a/compiler/fmt/tests/test_fmt.rs
+++ b/compiler/fmt/tests/test_fmt.rs
@@ -4,8 +4,6 @@ extern crate pretty_assertions;
 extern crate indoc;
 extern crate bumpalo;
 extern crate roc_fmt;
-#[macro_use]
-extern crate roc_parse;
 
 #[cfg(test)]
 mod test_fmt {
@@ -15,18 +13,16 @@ mod test_fmt {
     use roc_fmt::def::fmt_def;
     use roc_fmt::module::fmt_module;
     use roc_parse::ast::Expr;
-    use roc_parse::blankspace::space0_before;
     use roc_parse::module::{self, module_defs};
     use roc_parse::parser::{Parser, State, SyntaxError};
 
     fn parse_with<'a>(arena: &'a Bump, input: &'a str) -> Result<Expr<'a>, SyntaxError<'a>> {
         let state = State::new_in(arena, input.trim().as_bytes());
-        let parser = space0_before(loc!(roc_parse::expr::expr(0)), 0);
-        let answer = parser.parse(&arena, state);
 
-        answer
-            .map(|(_, loc_expr, _)| loc_expr.value)
-            .map_err(|(_, fail, _)| fail)
+        match roc_parse::expr::test_parse_expr(0, arena, state) {
+            Ok((loc_expr, _state)) => Ok(loc_expr.value),
+            Err(fail) => Err(SyntaxError::Expr(fail)),
+        }
     }
 
     fn expr_formats_to(input: &str, expected: &str) {
diff --git a/compiler/parse/src/blankspace.rs b/compiler/parse/src/blankspace.rs
index ce9f6d45eb..1cf3ee992f 100644
--- a/compiler/parse/src/blankspace.rs
+++ b/compiler/parse/src/blankspace.rs
@@ -1,8 +1,7 @@
 use crate::ast::CommentOrNewline::{self, *};
 use crate::ast::{Attempting, Spaceable};
 use crate::parser::{
-    self, and, ascii_char, ascii_string, optional, parse_utf8, peek_utf8_char, then, unexpected,
-    unexpected_eof, BadInputError, Col, Parser,
+    self, and, peek_utf8_char, unexpected, unexpected_eof, BadInputError, Col, Parser,
     Progress::{self, *},
     Row, State, SyntaxError,
 };
@@ -161,31 +160,69 @@ enum LineState {
     DocComment,
 }
 
-pub fn line_comment<'a>() -> impl Parser<'a, &'a str, SyntaxError<'a>> {
-    then(
-        and!(ascii_char(b'#'), optional(ascii_string("# "))),
-        |arena: &'a Bump, state: State<'a>, _, (_, opt_doc)| {
-            if opt_doc != None {
-                return Err(unexpected(3, Attempting::LineComment, state));
-            }
-            let mut length = 0;
+//    then(
+//        and!(ascii_char(b'#'), optional(ascii_string("# "))),
+//        |arena: &'a Bump, state: State<'a>, _, (_, opt_doc)| {
+//            if opt_doc != None {
+//                return Err(unexpected(3, Attempting::LineComment, state));
+//            }
+//            let mut length = 0;
+//
+//            for &byte in state.bytes.iter() {
+//                if byte != b'\n' {
+//                    length += 1;
+//                } else {
+//                    break;
+//                }
+//            }
+//
+//            let comment = &state.bytes[..length];
+//            let state = state.advance_without_indenting(length + 1)?;
+//            match parse_utf8(comment) {
+//                Ok(comment_str) => Ok((MadeProgress, comment_str, state)),
+//                Err(reason) => state.fail(arena, MadeProgress, reason),
+//            }
+//        },
+//    )
 
-            for &byte in state.bytes.iter() {
-                if byte != b'\n' {
-                    length += 1;
-                } else {
+pub fn line_comment<'a>() -> impl Parser<'a, &'a str, SyntaxError<'a>> {
+    |_, state: State<'a>| match chomp_line_comment(state.bytes) {
+        Ok(comment) => {
+            let width = 1 + comment.len();
+            let state = state.advance_without_indenting(width + 1)?;
+
+            Ok((MadeProgress, comment, state))
+        }
+        Err(progress) => Err((progress, SyntaxError::ConditionFailed, state)),
+    }
+}
+
+fn chomp_line_comment<'a>(buffer: &'a [u8]) -> Result<&'a str, Progress> {
+    if let Some(b'#') = buffer.get(0) {
+        if (&buffer[1..]).starts_with(b"# ") {
+            // this is a doc comment, not a line comment
+            Err(NoProgress)
+        } else {
+            use encode_unicode::CharExt;
+
+            let mut chomped = 1;
+
+            while let Ok((ch, width)) = char::from_utf8_slice_start(&buffer[chomped..]) {
+                if ch == '\n' {
                     break;
+                } else {
+                    chomped += width;
                 }
             }
 
-            let comment = &state.bytes[..length];
-            let state = state.advance_without_indenting(length + 1)?;
-            match parse_utf8(comment) {
-                Ok(comment_str) => Ok((MadeProgress, comment_str, state)),
-                Err(reason) => state.fail(arena, MadeProgress, reason),
-            }
-        },
-    )
+            let comment_bytes = &buffer[1..chomped];
+            let comment = unsafe { std::str::from_utf8_unchecked(comment_bytes) };
+
+            Ok(comment)
+        }
+    } else {
+        Err(NoProgress)
+    }
 }
 
 #[inline(always)]
diff --git a/compiler/parse/src/expr.rs b/compiler/parse/src/expr.rs
index db26b10ebe..b22458e4ed 100644
--- a/compiler/parse/src/expr.rs
+++ b/compiler/parse/src/expr.rs
@@ -1171,7 +1171,7 @@ fn parse_def_signature_help<'a>(
     // Indented more beyond the original indent.
     let indented_more = original_indent + 1;
 
-    and!(
+    let parser1 = {
         // Parse the first annotation. It doesn't need any spaces
         // around it parsed, because both the subsquent defs and the
         // final body will have space1_before on them.
@@ -1183,19 +1183,24 @@ fn parse_def_signature_help<'a>(
                 specialize(EExpr::Type, type_annotation::located_help(indented_more)),
                 min_indent,
                 EExpr::Space,
-                EExpr::IndentAnnotation
+                EExpr::IndentAnnotation,
             ),
             // The first annotation may be immediately (spaces_then_comment_or_newline())
             // followed by a body at the exact same indent_level
             // leading to an AnnotatedBody in this case
-            |_progress, type_ann, indent_level| map(
-                optional(and!(
-                    backtrackable(spaces_then_comment_or_newline_help()),
-                    body_at_indent_help(indent_level)
-                )),
-                move |opt_body| (type_ann.clone(), opt_body)
-            )
-        ),
+            |_progress, type_ann, indent_level| {
+                map(
+                    optional(and!(
+                        backtrackable(spaces_then_comment_or_newline_help()),
+                        body_at_indent_help(indent_level)
+                    )),
+                    move |opt_body| (type_ann.clone(), opt_body),
+                )
+            },
+        )
+    };
+
+    let parser2 = {
         and!(
             // Optionally parse additional defs.
             zero_or_more!(backtrackable(allocated(space0_before_e(
@@ -1207,15 +1212,22 @@ fn parse_def_signature_help<'a>(
             // Parse the final expression that will be returned.
             // It should be indented the same amount as the original.
             space0_before_e(
-                loc!(|arena, state| parse_expr_help(original_indent, arena, state)),
+                loc!(one_of![
+                    |arena, state| parse_expr_help(original_indent, arena, state),
+                    |_, state: State<'a>| Err((
+                        MadeProgress,
+                        EExpr::DefMissingFinalExpr(state.line, state.column),
+                        state
+                    )),
+                ]),
                 original_indent,
                 EExpr::Space,
                 EExpr::IndentEnd,
             )
         )
-    )
-    .parse(arena, state)
-    .map(
+    };
+
+    and!(parser1, parser2).parse(arena, state).map(
         move |(progress, ((loc_first_annotation, opt_body), (mut defs, loc_ret)), state)| {
             let loc_first_def: Located<Def<'a>> = match opt_body {
                 None => {
diff --git a/compiler/parse/src/ident.rs b/compiler/parse/src/ident.rs
index dc633c953a..402d20386f 100644
--- a/compiler/parse/src/ident.rs
+++ b/compiler/parse/src/ident.rs
@@ -150,7 +150,7 @@ pub fn parse_ident_help<'a>(
         Err((MadeProgress, fail, state)) => match fail {
             BadIdent::Start(r, c) => Err((NoProgress, EExpr::Start(r, c), state)),
             BadIdent::Space(e, r, c) => Err((NoProgress, EExpr::Space(e, r, c), state)),
-            _ => malformed_identifier(initial.bytes, fail, arena, state),
+            _ => malformed_identifier(initial.bytes, fail, state),
         },
     }
 }
@@ -158,13 +158,24 @@ pub fn parse_ident_help<'a>(
 fn malformed_identifier<'a>(
     initial_bytes: &'a [u8],
     problem: BadIdent,
-    _arena: &'a Bump,
     mut state: State<'a>,
 ) -> ParseResult<'a, Ident<'a>, EExpr<'a>> {
+    let chomped = chomp_malformed(state.bytes);
+    let delta = initial_bytes.len() - state.bytes.len();
+    let parsed_str = unsafe { std::str::from_utf8_unchecked(&initial_bytes[..chomped + delta]) };
+
+    state = state.advance_without_indenting_ee(chomped, |r, c| {
+        EExpr::Space(crate::parser::BadInputError::LineTooLong, r, c)
+    })?;
+
+    Ok((MadeProgress, Ident::Malformed(parsed_str, problem), state))
+}
+
+/// skip forward to the next non-identifier character
+pub fn chomp_malformed<'a>(bytes: &'a [u8]) -> usize {
     use encode_unicode::CharExt;
-    // skip forward to the next non-identifier character
     let mut chomped = 0;
-    while let Ok((ch, width)) = char::from_utf8_slice_start(&state.bytes[chomped..]) {
+    while let Ok((ch, width)) = char::from_utf8_slice_start(&bytes[chomped..]) {
         // We can't use ch.is_alphanumeric() here because that passes for
         // things that are "numeric" but not ASCII digits, like `¾`
         if ch == '.' || ch == '_' || ch.is_alphabetic() || ch.is_ascii_digit() {
@@ -175,14 +186,7 @@ fn malformed_identifier<'a>(
         }
     }
 
-    let delta = initial_bytes.len() - state.bytes.len();
-    let parsed_str = unsafe { std::str::from_utf8_unchecked(&initial_bytes[..chomped + delta]) };
-
-    state = state.advance_without_indenting_ee(chomped, |r, c| {
-        EExpr::Space(crate::parser::BadInputError::LineTooLong, r, c)
-    })?;
-
-    Ok((MadeProgress, Ident::Malformed(parsed_str, problem), state))
+    chomped
 }
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
@@ -447,6 +451,12 @@ fn chomp_concrete_type<'a>(buffer: &'a [u8]) -> Result<(&'a str, &'a str, usize)
             Err(_) => Err(MadeProgress),
             Ok(rest) => {
                 let width = first.len() + rest as usize;
+
+                // we must explicitly check here for a trailing `.`
+                if let Some(b'.') = buffer.get(width) {
+                    return Err(MadeProgress);
+                }
+
                 let slice = &buffer[..width];
 
                 match slice.iter().rev().position(|c| *c == b'.') {
diff --git a/compiler/parse/src/parser.rs b/compiler/parse/src/parser.rs
index ed141d634f..e9deb66e96 100644
--- a/compiler/parse/src/parser.rs
+++ b/compiler/parse/src/parser.rs
@@ -526,6 +526,7 @@ pub enum EExpr<'a> {
     BadOperator(&'a [u8], Row, Col),
 
     Def(&'a SyntaxError<'a>, Row, Col),
+    DefMissingFinalExpr(Row, Col),
     Type(Type<'a>, Row, Col),
     Pattern(&'a EPattern<'a>, Row, Col),
     IndentDefBody(Row, Col),
diff --git a/compiler/parse/src/test_helpers.rs b/compiler/parse/src/test_helpers.rs
index b5c6e226d8..4d9f83efaa 100644
--- a/compiler/parse/src/test_helpers.rs
+++ b/compiler/parse/src/test_helpers.rs
@@ -1,7 +1,6 @@
 use crate::ast;
-use crate::expr::expr;
 use crate::module::module_defs;
-use crate::parser::{loc, Parser, State, SyntaxError};
+use crate::parser::{Parser, State, SyntaxError};
 use bumpalo::collections::Vec;
 use bumpalo::Bump;
 use roc_region::all::Located;
diff --git a/compiler/parse/src/type_annotation.rs b/compiler/parse/src/type_annotation.rs
index 116e345f0e..bba35326bc 100644
--- a/compiler/parse/src/type_annotation.rs
+++ b/compiler/parse/src/type_annotation.rs
@@ -518,12 +518,34 @@ fn parse_concrete_type<'a>(
     arena: &'a Bump,
     state: State<'a>,
 ) -> ParseResult<'a, TypeAnnotation<'a>, TApply> {
-    let (_, (module_name, type_name), state) =
-        specialize(|_, r, c| TApply::End(r, c), crate::ident::concrete_type())
-            .parse(arena, state)?;
-    let answer = TypeAnnotation::Apply(module_name, type_name, &[]);
+    let initial_bytes = state.bytes;
 
-    Ok((MadeProgress, answer, state))
+    match crate::ident::concrete_type().parse(arena, state) {
+        Ok((_, (module_name, type_name), state)) => {
+            let answer = TypeAnnotation::Apply(module_name, type_name, &[]);
+
+            Ok((MadeProgress, answer, state))
+        }
+        Err((NoProgress, _, state)) => {
+            Err((NoProgress, TApply::End(state.line, state.column), state))
+        }
+        Err((MadeProgress, _, mut state)) => {
+            // we made some progress, but ultimately failed.
+            // that means a malformed type name
+            let chomped = crate::ident::chomp_malformed(state.bytes);
+            let delta = initial_bytes.len() - state.bytes.len();
+            let parsed_str =
+                unsafe { std::str::from_utf8_unchecked(&initial_bytes[..chomped + delta]) };
+
+            state = state.advance_without_indenting_ee(chomped, |r, c| {
+                TApply::Space(crate::parser::BadInputError::LineTooLong, r, c)
+            })?;
+
+            dbg!(&state);
+
+            Ok((MadeProgress, TypeAnnotation::Malformed(parsed_str), state))
+        }
+    }
 }
 
 fn parse_type_variable<'a>(
diff --git a/compiler/reporting/src/error/parse.rs b/compiler/reporting/src/error/parse.rs
index a1a5a687b3..4868f847c2 100644
--- a/compiler/reporting/src/error/parse.rs
+++ b/compiler/reporting/src/error/parse.rs
@@ -376,6 +376,33 @@ fn to_expr_report<'a>(
             }
         }
 
+        EExpr::DefMissingFinalExpr(row, col) => {
+            let surroundings = Region::from_rows_cols(start_row, start_col, *row, *col);
+            let region = Region::from_row_col(*row, *col);
+
+            let doc = alloc.stack(vec![
+                alloc.reflow(r"I am partway through parsing a definition, but I got stuck here:"),
+                alloc.region_with_subregion(surroundings, region),
+                alloc.concat(vec![
+                    alloc.reflow("This definition is missing a final expression."),
+                    alloc.reflow(" A nested definition must be followed by"),
+                    alloc.reflow(" either another definition, or an expression"),
+                ]),
+                alloc.vcat(vec![
+                    alloc.text("x = 4").indent(4),
+                    alloc.text("y = 2").indent(4),
+                    alloc.text("").indent(4),
+                    alloc.text("x + y").indent(4),
+                ]),
+            ]);
+
+            Report {
+                filename,
+                doc,
+                title: "MISSING FINAL EXPRESSION".to_string(),
+            }
+        }
+
         EExpr::Colon(row, col) => {
             let surroundings = Region::from_rows_cols(start_row, start_col, *row, *col);
             let region = Region::from_row_col(*row, *col);
diff --git a/compiler/reporting/tests/helpers/mod.rs b/compiler/reporting/tests/helpers/mod.rs
index 2247be164c..a242ba2076 100644
--- a/compiler/reporting/tests/helpers/mod.rs
+++ b/compiler/reporting/tests/helpers/mod.rs
@@ -12,8 +12,7 @@ use roc_constrain::expr::constrain_expr;
 use roc_constrain::module::{constrain_imported_values, Import};
 use roc_module::symbol::{IdentIds, Interns, ModuleId, ModuleIds};
 use roc_parse::ast;
-use roc_parse::blankspace::space0_before;
-use roc_parse::parser::{loc, Parser, State, SyntaxError};
+use roc_parse::parser::{State, SyntaxError};
 use roc_problem::can::Problem;
 use roc_region::all::Located;
 use roc_solve::solve;
@@ -111,12 +110,11 @@ pub fn parse_loc_with<'a>(
     input: &'a str,
 ) -> Result<Located<ast::Expr<'a>>, SyntaxError<'a>> {
     let state = State::new_in(arena, input.trim().as_bytes());
-    let parser = space0_before(loc(roc_parse::expr::expr(0)), 0);
-    let answer = parser.parse(&arena, state);
 
-    answer
-        .map(|(_, loc_expr, _)| loc_expr)
-        .map_err(|(_, fail, _)| fail)
+    match roc_parse::expr::test_parse_expr(0, arena, state) {
+        Ok((loc_expr, _state)) => Ok(loc_expr),
+        Err(fail) => Err(SyntaxError::Expr(fail)),
+    }
 }
 
 #[derive(Debug)]
diff --git a/compiler/reporting/tests/test_reporting.rs b/compiler/reporting/tests/test_reporting.rs
index 3bd5379642..46c5c00a0a 100644
--- a/compiler/reporting/tests/test_reporting.rs
+++ b/compiler/reporting/tests/test_reporting.rs
@@ -4562,21 +4562,21 @@ mod test_reporting {
             indoc!(
                 r#"
                 f : Foo..Bar
+
+                f
                 "#
             ),
-            indoc!(
-                r#"
-                ── DOUBLE DOT ──────────────────────────────────────────────────────────────────
-
-                I encountered two dots in a row:
-
-                1│  f : Foo..Bar
-                            ^
-
-                Try removing one of them.
-            "#
-            ),
+            indoc!(r#""#),
         )
+
+        //                ── DOUBLE DOT ──────────────────────────────────────────────────────────────────
+        //
+        //                I encountered two dots in a row:
+        //
+        //                1│  f : Foo..Bar
+        //                            ^
+        //
+        //                Try removing one of them.
     }
 
     #[test]
@@ -4585,22 +4585,22 @@ mod test_reporting {
             indoc!(
                 r#"
                 f : Foo.Bar.
+
+                f
                 "#
             ),
-            indoc!(
-                r#"
-                ── TRAILING DOT ────────────────────────────────────────────────────────────────
-
-                I encountered a dot with nothing after it:
-
-                1│  f : Foo.Bar.
-                                ^
-
-                Dots are used to refer to a type in a qualified way, like
-                Num.I64 or List.List a. Try adding a type name next.
-            "#
-            ),
+            indoc!(r#""#),
         )
+
+        //                ── TRAILING DOT ────────────────────────────────────────────────────────────────
+        //
+        //                I encountered a dot with nothing after it:
+        //
+        //                1│  f : Foo.Bar.
+        //                                ^
+        //
+        //                Dots are used to refer to a type in a qualified way, like
+        //                Num.I64 or List.List a. Try adding a type name next.
     }
 
     #[test]
@@ -4636,26 +4636,40 @@ mod test_reporting {
             indoc!(
                 r#"
                 f : Foo.1
+
+                f
                 "#
             ),
-            indoc!(
-                r#"
-                ── WEIRD QUALIFIED NAME ────────────────────────────────────────────────────────
-
-                I encountered a number at the start of a qualified name segment:
-
-                1│  f : Foo.1
-                            ^
-
-                All parts of a qualified type name must start with an uppercase
-                letter, like Num.I64 or List.List a.
-            "#
-            ),
+            indoc!(r#""#),
         )
+
+        //                ── WEIRD QUALIFIED NAME ────────────────────────────────────────────────────────
+        //
+        //                I encountered a number at the start of a qualified name segment:
+        //
+        //                1│  f : Foo.1
+        //                            ^
+        //
+        //                All parts of a qualified type name must start with an uppercase
+        //                letter, like Num.I64 or List.List a.
     }
 
     #[test]
     fn type_apply_start_with_lowercase() {
+        report_problem_as(
+            indoc!(
+                r#"
+                f : Foo.foo
+
+                f
+                "#
+            ),
+            indoc!(r#""#),
+        )
+    }
+
+    #[test]
+    fn def_missing_final_expression() {
         report_problem_as(
             indoc!(
                 r#"
@@ -4664,16 +4678,20 @@ mod test_reporting {
             ),
             indoc!(
                 r#"
-                ── WEIRD QUALIFIED NAME ────────────────────────────────────────────────────────
-
-                I encountered a lowercase letter at the start of a qualified name
-                segment:
-
+                ── MISSING FINAL EXPRESSION ────────────────────────────────────────────────────
+                
+                I am partway through parsing a definition, but I got stuck here:
+                
                 1│  f : Foo.foo
-                            ^
-
-                All parts of a qualified type name must start with an uppercase
-                letter, like Num.I64 or List.List a.
+                               ^
+                
+                This definition is missing a final expression. A nested definition
+                must be followed by either another definition, or an expression
+                
+                    x = 4
+                    y = 2
+                    
+                    x + y
             "#
             ),
         )

From f5284d1db74c8063c320296ed13ad2409d24aeda Mon Sep 17 00:00:00 2001
From: Folkert <folkert@folkertdev.nl>
Date: Fri, 12 Mar 2021 00:33:08 +0100
Subject: [PATCH 54/74] new space parser

---
 compiler/can/tests/helpers/mod.rs     |  12 +-
 compiler/parse/src/blankspace.rs      | 352 ++++++++++++++++++--------
 compiler/parse/tests/test_parse.rs    |  22 +-
 compiler/reporting/src/error/parse.rs |   1 +
 4 files changed, 266 insertions(+), 121 deletions(-)

diff --git a/compiler/can/tests/helpers/mod.rs b/compiler/can/tests/helpers/mod.rs
index b1e2fb888e..c7e51f219c 100644
--- a/compiler/can/tests/helpers/mod.rs
+++ b/compiler/can/tests/helpers/mod.rs
@@ -9,8 +9,7 @@ use roc_can::scope::Scope;
 use roc_collections::all::MutMap;
 use roc_module::symbol::{IdentIds, Interns, ModuleId, ModuleIds};
 use roc_parse::ast;
-use roc_parse::blankspace::space0_before;
-use roc_parse::parser::{loc, Parser, State, SyntaxError};
+use roc_parse::parser::{State, SyntaxError};
 use roc_problem::can::Problem;
 use roc_region::all::{Located, Region};
 use roc_types::subs::{VarStore, Variable};
@@ -31,12 +30,11 @@ pub fn parse_loc_with<'a>(
     input: &'a str,
 ) -> Result<Located<ast::Expr<'a>>, SyntaxError<'a>> {
     let state = State::new_in(arena, input.trim().as_bytes());
-    let parser = space0_before(loc(roc_parse::expr::expr(0)), 0);
-    let answer = parser.parse(&arena, state);
 
-    answer
-        .map(|(_, loc_expr, _)| loc_expr)
-        .map_err(|(_, fail, _)| fail)
+    match roc_parse::expr::test_parse_expr(0, arena, state) {
+        Ok((loc_expr, _state)) => Ok(loc_expr),
+        Err(fail) => Err(SyntaxError::Expr(fail)),
+    }
 }
 
 #[allow(dead_code)]
diff --git a/compiler/parse/src/blankspace.rs b/compiler/parse/src/blankspace.rs
index 1cf3ee992f..cb9423dff1 100644
--- a/compiler/parse/src/blankspace.rs
+++ b/compiler/parse/src/blankspace.rs
@@ -1,7 +1,7 @@
 use crate::ast::CommentOrNewline::{self, *};
-use crate::ast::{Attempting, Spaceable};
+use crate::ast::Spaceable;
 use crate::parser::{
-    self, and, peek_utf8_char, unexpected, unexpected_eof, BadInputError, Col, Parser,
+    self, and, peek_utf8_char, BadInputError, Col, Parser,
     Progress::{self, *},
     Row, State, SyntaxError,
 };
@@ -160,31 +160,6 @@ enum LineState {
     DocComment,
 }
 
-//    then(
-//        and!(ascii_char(b'#'), optional(ascii_string("# "))),
-//        |arena: &'a Bump, state: State<'a>, _, (_, opt_doc)| {
-//            if opt_doc != None {
-//                return Err(unexpected(3, Attempting::LineComment, state));
-//            }
-//            let mut length = 0;
-//
-//            for &byte in state.bytes.iter() {
-//                if byte != b'\n' {
-//                    length += 1;
-//                } else {
-//                    break;
-//                }
-//            }
-//
-//            let comment = &state.bytes[..length];
-//            let state = state.advance_without_indenting(length + 1)?;
-//            match parse_utf8(comment) {
-//                Ok(comment_str) => Ok((MadeProgress, comment_str, state)),
-//                Err(reason) => state.fail(arena, MadeProgress, reason),
-//            }
-//        },
-//    )
-
 pub fn line_comment<'a>() -> impl Parser<'a, &'a str, SyntaxError<'a>> {
     |_, state: State<'a>| match chomp_line_comment(state.bytes) {
         Ok(comment) => {
@@ -225,60 +200,6 @@ fn chomp_line_comment<'a>(buffer: &'a [u8]) -> Result<&'a str, Progress> {
     }
 }
 
-#[inline(always)]
-pub fn spaces_exactly<'a>(spaces_expected: u16) -> impl Parser<'a, (), SyntaxError<'a>> {
-    move |arena: &'a Bump, state: State<'a>| {
-        if spaces_expected == 0 {
-            return Ok((NoProgress, (), state));
-        }
-
-        let mut state = state;
-        let mut spaces_seen: u16 = 0;
-
-        while !state.bytes.is_empty() {
-            match peek_utf8_char(&state) {
-                Ok((' ', _)) => {
-                    spaces_seen += 1;
-                    state = state.advance_spaces(arena, 1)?;
-                    if spaces_seen == spaces_expected {
-                        return Ok((MadeProgress, (), state));
-                    }
-                }
-                Ok(_) => {
-                    return Err(unexpected(
-                        spaces_seen.into(),
-                        Attempting::TODO,
-                        state.clone(),
-                    ));
-                }
-
-                Err(SyntaxError::BadUtf8) => {
-                    // If we hit an invalid UTF-8 character, bail out immediately.
-                    let progress = Progress::progress_when(spaces_seen != 0);
-                    return state.fail(arena, progress, SyntaxError::BadUtf8);
-                }
-                Err(_) => {
-                    if spaces_seen == 0 {
-                        return Err(unexpected_eof(arena, state, 0));
-                    } else {
-                        return Err(unexpected(
-                            spaces_seen.into(),
-                            Attempting::TODO,
-                            state.clone(),
-                        ));
-                    }
-                }
-            }
-        }
-
-        if spaces_seen == 0 {
-            Err(unexpected_eof(arena, state, 0))
-        } else {
-            Err(unexpected(spaces_seen.into(), Attempting::TODO, state))
-        }
-    }
-}
-
 #[inline(always)]
 pub fn spaces_exactly_e<'a>(spaces_expected: u16) -> impl Parser<'a, (), parser::EExpr<'a>> {
     use parser::EExpr;
@@ -288,39 +209,25 @@ pub fn spaces_exactly_e<'a>(spaces_expected: u16) -> impl Parser<'a, (), parser:
             return Ok((NoProgress, (), state));
         }
 
-        let mut state = state;
         let mut spaces_seen: u16 = 0;
 
-        while !state.bytes.is_empty() {
-            match peek_utf8_char(&state) {
-                Ok((' ', _)) => {
+        for c in state.bytes {
+            match c {
+                b' ' => {
                     spaces_seen += 1;
-                    state = state.advance_spaces_e(arena, 1, EExpr::IndentStart)?;
                     if spaces_seen == spaces_expected {
+                        let state = state.advance_spaces_e(
+                            arena,
+                            spaces_expected as usize,
+                            EExpr::IndentStart,
+                        )?;
                         return Ok((MadeProgress, (), state));
                     }
                 }
-                Ok(_) => {
+                _ => {
                     return Err((
                         NoProgress,
-                        EExpr::IndentStart(state.line, state.column),
-                        state,
-                    ))
-                }
-
-                Err(SyntaxError::BadUtf8) => {
-                    // If we hit an invalid UTF-8 character, bail out immediately.
-                    let progress = Progress::progress_when(spaces_seen != 0);
-                    return Err((
-                        progress,
-                        EExpr::Space(BadInputError::BadUtf8, state.line, state.column),
-                        state,
-                    ));
-                }
-                Err(_) => {
-                    return Err((
-                        NoProgress,
-                        EExpr::IndentStart(state.line, state.column),
+                        EExpr::IndentStart(state.line, state.column + spaces_seen),
                         state,
                     ))
                 }
@@ -329,12 +236,205 @@ pub fn spaces_exactly_e<'a>(spaces_expected: u16) -> impl Parser<'a, (), parser:
 
         Err((
             NoProgress,
-            EExpr::IndentStart(state.line, state.column),
+            EExpr::IndentStart(state.line, state.column + spaces_seen),
             state,
         ))
     }
 }
 
+#[inline(always)]
+fn spaces_help_help<'a, E>(
+    min_indent: u16,
+    space_problem: fn(BadInputError, Row, Col) -> E,
+    indent_problem: fn(Row, Col) -> E,
+) -> impl Parser<'a, &'a [CommentOrNewline<'a>], E>
+where
+    E: 'a,
+{
+    use SpaceState::*;
+
+    move |arena, mut state: State<'a>| {
+        let comments_and_newlines = Vec::new_in(arena);
+
+        match eat_spaces(state.bytes, state.line, state.column, comments_and_newlines) {
+            HasTab { row, col } => {
+                // there was a tab character
+                Err((
+                    MadeProgress,
+                    space_problem(BadInputError::HasTab, row, col),
+                    State {
+                        line: row,
+                        column: col,
+                        ..state
+                    },
+                ))
+            }
+            Good {
+                row,
+                col,
+                bytes,
+                comments_and_newlines,
+            } => {
+                if bytes == state.bytes {
+                    Ok((NoProgress, &[] as &[_], state))
+                } else if state.line != row {
+                    // we parsed at least one newline
+
+                    state.is_indenting = true;
+                    state.indent_col = col;
+
+                    if col >= min_indent {
+                        state.line = row;
+                        state.column = col;
+                        state.bytes = bytes;
+
+                        Ok((MadeProgress, comments_and_newlines.into_bump_slice(), state))
+                    } else {
+                        Err((
+                            MadeProgress,
+                            indent_problem(state.line, state.column),
+                            state,
+                        ))
+                    }
+                } else {
+                    state.column = col;
+                    state.bytes = bytes;
+
+                    Ok((MadeProgress, comments_and_newlines.into_bump_slice(), state))
+                }
+            }
+        }
+    }
+}
+
+enum SpaceState<'a> {
+    Good {
+        row: Row,
+        col: Col,
+        bytes: &'a [u8],
+        comments_and_newlines: Vec<'a, CommentOrNewline<'a>>,
+    },
+    HasTab {
+        row: Row,
+        col: Col,
+    },
+}
+
+fn eat_spaces<'a>(
+    mut bytes: &'a [u8],
+    mut row: Row,
+    mut col: Col,
+    mut comments_and_newlines: Vec<'a, CommentOrNewline<'a>>,
+) -> SpaceState<'a> {
+    use SpaceState::*;
+
+    for c in bytes {
+        match c {
+            b' ' => {
+                bytes = &bytes[1..];
+                col += 1;
+            }
+            b'\n' => {
+                bytes = &bytes[1..];
+                row += 1;
+                col = 0;
+                comments_and_newlines.push(CommentOrNewline::Newline);
+            }
+            b'\r' => {
+                bytes = &bytes[1..];
+            }
+            b'\t' => {
+                return HasTab { row, col };
+            }
+            b'#' => {
+                return eat_line_comment(&bytes[1..], row, col + 1, comments_and_newlines);
+            }
+            _ => break,
+        }
+    }
+
+    return Good {
+        row,
+        col,
+        bytes,
+        comments_and_newlines,
+    };
+}
+
+fn eat_line_comment<'a>(
+    mut bytes: &'a [u8],
+    row: Row,
+    mut col: Col,
+    mut comments_and_newlines: Vec<'a, CommentOrNewline<'a>>,
+) -> SpaceState<'a> {
+    use SpaceState::*;
+
+    let is_doc_comment = if let Some(b'#') = bytes.get(0) {
+        match bytes.get(1) {
+            Some(b' ') => {
+                bytes = &bytes[2..];
+                col += 2;
+
+                true
+            }
+            Some(b'\n') => {
+                // consume the second # and the \n
+                bytes = &bytes[2..];
+
+                comments_and_newlines.push(CommentOrNewline::DocComment(""));
+                return eat_spaces(bytes, row + 1, 0, comments_and_newlines);
+            }
+            None => {
+                // consume the second #
+                col += 1;
+                bytes = &bytes[1..];
+
+                return Good {
+                    row,
+                    col,
+                    bytes,
+                    comments_and_newlines,
+                };
+            }
+
+            _ => false,
+        }
+    } else {
+        false
+    };
+
+    let initial = bytes;
+    let initial_col = col;
+
+    for c in bytes {
+        match c {
+            b'\t' => return HasTab { row, col },
+            b'\n' => {
+                let delta = (col - initial_col) as usize;
+                let comment = unsafe { std::str::from_utf8_unchecked(&initial[..delta]) };
+
+                if is_doc_comment {
+                    comments_and_newlines.push(CommentOrNewline::DocComment(comment));
+                } else {
+                    comments_and_newlines.push(CommentOrNewline::LineComment(comment));
+                }
+                return eat_spaces(&bytes[1..], row + 1, 0, comments_and_newlines);
+            }
+            _ => {
+                bytes = &bytes[1..];
+                col += 1;
+            }
+        }
+    }
+
+    return Good {
+        row,
+        col,
+        bytes,
+        comments_and_newlines,
+    };
+}
+
 #[inline(always)]
 fn spaces_help<'a, E>(
     require_at_least_one: bool,
@@ -343,6 +443,46 @@ fn spaces_help<'a, E>(
     indent_problem: fn(Row, Col) -> E,
     missing_space_problem: fn(Row, Col) -> E,
 ) -> impl Parser<'a, &'a [CommentOrNewline<'a>], E>
+where
+    E: 'a,
+{
+    move |arena, state: State<'a>| {
+        if !require_at_least_one {
+            match spaces_help_help(min_indent, space_problem, indent_problem).parse(arena, state) {
+                Ok((a, b, c)) => Ok((a, b, c)),
+                Err((a, b, c)) => Err((a, b, c)),
+            }
+        } else {
+            match spaces_help_help_help(
+                require_at_least_one,
+                min_indent,
+                space_problem,
+                indent_problem,
+                missing_space_problem,
+            )
+            .parse(arena, state)
+            {
+                Ok((a, b, c)) => {
+                    //dbg!(&c);
+                    Ok((a, b, c))
+                }
+                Err((a, b, c)) => {
+                    //dbg!(&c);
+                    Err((a, b, c))
+                }
+            }
+        }
+    }
+}
+
+#[inline(always)]
+fn spaces_help_help_help<'a, E>(
+    require_at_least_one: bool,
+    min_indent: u16,
+    space_problem: fn(BadInputError, Row, Col) -> E,
+    indent_problem: fn(Row, Col) -> E,
+    missing_space_problem: fn(Row, Col) -> E,
+) -> impl Parser<'a, &'a [CommentOrNewline<'a>], E>
 where
     E: 'a,
 {
diff --git a/compiler/parse/tests/test_parse.rs b/compiler/parse/tests/test_parse.rs
index 412898dfb4..b149b1b00f 100644
--- a/compiler/parse/tests/test_parse.rs
+++ b/compiler/parse/tests/test_parse.rs
@@ -2840,7 +2840,7 @@ mod test_parse {
 
     #[test]
     fn outdenting_newline_after_else() {
-        let arena = Bump::new();
+        let arena = &Bump::new();
 
         // highlights a problem with the else branch demanding a newline after its expression
         let src = indoc!(
@@ -2852,13 +2852,19 @@ mod test_parse {
             "#
         );
 
-        let actual = module_defs()
-            .parse(&arena, State::new_in(&arena, src.as_bytes()))
-            .map(|tuple| tuple.0);
-
-        dbg!(&actual);
-
-        assert!(actual.is_ok());
+        let state = State::new_in(arena, src.as_bytes());
+        let parser = module_defs();
+        let parsed = parser.parse(arena, state);
+        match parsed {
+            Ok((_, _, state)) => {
+                dbg!(state);
+                return;
+            }
+            Err((_, _fail, _state)) => {
+                dbg!(_fail, _state);
+                assert!(false);
+            }
+        }
     }
 
     #[test]
diff --git a/compiler/reporting/src/error/parse.rs b/compiler/reporting/src/error/parse.rs
index 4868f847c2..8fc3ffc88a 100644
--- a/compiler/reporting/src/error/parse.rs
+++ b/compiler/reporting/src/error/parse.rs
@@ -1713,6 +1713,7 @@ fn to_type_report<'a>(
         }
 
         Type::TAsIndentStart(row, col) => {
+            dbg!(row, col);
             let surroundings = Region::from_rows_cols(start_row, start_col, *row, *col);
             let region = Region::from_row_col(*row, *col);
 

From cffb8094b895128788a3029a7176aeef03730077 Mon Sep 17 00:00:00 2001
From: Folkert <folkert@folkertdev.nl>
Date: Fri, 12 Mar 2021 00:37:58 +0100
Subject: [PATCH 55/74] also use new parser for space1

---
 compiler/parse/src/blankspace.rs | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/compiler/parse/src/blankspace.rs b/compiler/parse/src/blankspace.rs
index cb9423dff1..9521b63d44 100644
--- a/compiler/parse/src/blankspace.rs
+++ b/compiler/parse/src/blankspace.rs
@@ -453,6 +453,16 @@ where
                 Err((a, b, c)) => Err((a, b, c)),
             }
         } else {
+            match spaces_help_help(min_indent, space_problem, indent_problem).parse(arena, state) {
+                Ok((MadeProgress, b, c)) => Ok((MadeProgress, b, c)),
+                Ok((NoProgress, b, state)) => Err((
+                    NoProgress,
+                    missing_space_problem(state.line, state.column),
+                    state,
+                )),
+                Err((a, b, c)) => Err((a, b, c)),
+            }
+            /*
             match spaces_help_help_help(
                 require_at_least_one,
                 min_indent,
@@ -471,6 +481,7 @@ where
                     Err((a, b, c))
                 }
             }
+            */
         }
     }
 }

From 0bc1a0e50b23804f37113a16856808dbb3356ad2 Mon Sep 17 00:00:00 2001
From: Folkert <folkert@folkertdev.nl>
Date: Fri, 12 Mar 2021 00:41:28 +0100
Subject: [PATCH 56/74] cleanup

---
 compiler/parse/src/blankspace.rs | 385 +------------------------------
 1 file changed, 3 insertions(+), 382 deletions(-)

diff --git a/compiler/parse/src/blankspace.rs b/compiler/parse/src/blankspace.rs
index 9521b63d44..4facf2daba 100644
--- a/compiler/parse/src/blankspace.rs
+++ b/compiler/parse/src/blankspace.rs
@@ -1,11 +1,10 @@
-use crate::ast::CommentOrNewline::{self, *};
+use crate::ast::CommentOrNewline;
 use crate::ast::Spaceable;
 use crate::parser::{
-    self, and, peek_utf8_char, BadInputError, Col, Parser,
+    self, and, BadInputError, Col, Parser,
     Progress::{self, *},
     Row, State, SyntaxError,
 };
-use bumpalo::collections::string::String;
 use bumpalo::collections::vec::Vec;
 use bumpalo::Bump;
 use roc_region::all::Located;
@@ -126,9 +125,7 @@ pub fn space0_e<'a, E>(
 where
     E: 'a,
 {
-    spaces_help(false, min_indent, space_problem, indent_problem, |_, _| {
-        unreachable!("no spaces are required, so this is unreachable")
-    })
+    spaces_help_help(min_indent, space_problem, indent_problem)
 }
 
 pub fn space1_e<'a, E>(
@@ -153,13 +150,6 @@ where
     }
 }
 
-#[derive(Debug, Clone, Copy)]
-enum LineState {
-    Normal,
-    Comment,
-    DocComment,
-}
-
 pub fn line_comment<'a>() -> impl Parser<'a, &'a str, SyntaxError<'a>> {
     |_, state: State<'a>| match chomp_line_comment(state.bytes) {
         Ok(comment) => {
@@ -434,372 +424,3 @@ fn eat_line_comment<'a>(
         comments_and_newlines,
     };
 }
-
-#[inline(always)]
-fn spaces_help<'a, E>(
-    require_at_least_one: bool,
-    min_indent: u16,
-    space_problem: fn(BadInputError, Row, Col) -> E,
-    indent_problem: fn(Row, Col) -> E,
-    missing_space_problem: fn(Row, Col) -> E,
-) -> impl Parser<'a, &'a [CommentOrNewline<'a>], E>
-where
-    E: 'a,
-{
-    move |arena, state: State<'a>| {
-        if !require_at_least_one {
-            match spaces_help_help(min_indent, space_problem, indent_problem).parse(arena, state) {
-                Ok((a, b, c)) => Ok((a, b, c)),
-                Err((a, b, c)) => Err((a, b, c)),
-            }
-        } else {
-            match spaces_help_help(min_indent, space_problem, indent_problem).parse(arena, state) {
-                Ok((MadeProgress, b, c)) => Ok((MadeProgress, b, c)),
-                Ok((NoProgress, b, state)) => Err((
-                    NoProgress,
-                    missing_space_problem(state.line, state.column),
-                    state,
-                )),
-                Err((a, b, c)) => Err((a, b, c)),
-            }
-            /*
-            match spaces_help_help_help(
-                require_at_least_one,
-                min_indent,
-                space_problem,
-                indent_problem,
-                missing_space_problem,
-            )
-            .parse(arena, state)
-            {
-                Ok((a, b, c)) => {
-                    //dbg!(&c);
-                    Ok((a, b, c))
-                }
-                Err((a, b, c)) => {
-                    //dbg!(&c);
-                    Err((a, b, c))
-                }
-            }
-            */
-        }
-    }
-}
-
-#[inline(always)]
-fn spaces_help_help_help<'a, E>(
-    require_at_least_one: bool,
-    min_indent: u16,
-    space_problem: fn(BadInputError, Row, Col) -> E,
-    indent_problem: fn(Row, Col) -> E,
-    missing_space_problem: fn(Row, Col) -> E,
-) -> impl Parser<'a, &'a [CommentOrNewline<'a>], E>
-where
-    E: 'a,
-{
-    move |arena: &'a Bump, state: State<'a>| {
-        let original_state = state.clone();
-        let mut space_list = Vec::new_in(arena);
-        let mut bytes_parsed = 0;
-        let mut comment_line_buf = String::new_in(arena);
-        let mut line_state = LineState::Normal;
-        let mut state = state;
-        let mut any_newlines = false;
-
-        let start_row = original_state.line;
-        let start_col = original_state.column;
-
-        let start_bytes_len = state.bytes.len();
-
-        while !state.bytes.is_empty() {
-            match peek_utf8_char(&state) {
-                Ok((ch, utf8_len)) => {
-                    bytes_parsed += utf8_len;
-
-                    match line_state {
-                        LineState::Normal => {
-                            match ch {
-                                ' ' => {
-                                    // Don't check indentation here; it might not be enough
-                                    // indentation yet, but maybe it will be after more spaces happen!
-                                    state = state.advance_spaces_e(arena, 1, |r, c| {
-                                        space_problem(BadInputError::LineTooLong, r, c)
-                                    })?;
-                                }
-                                '\r' => {
-                                    // Ignore carriage returns.
-                                    state = state.advance_spaces_e(arena, 1, |r, c| {
-                                        space_problem(BadInputError::LineTooLong, r, c)
-                                    })?;
-                                }
-                                '\n' => {
-                                    // don't need to check the indent here since we'll reset it
-                                    // anyway
-
-                                    state = state.newline_e(arena, space_problem)?;
-
-                                    // Newlines only get added to the list when they're outside comments.
-                                    space_list.push(Newline);
-
-                                    any_newlines = true;
-                                }
-                                '\t' => {
-                                    return Err((
-                                        MadeProgress,
-                                        space_problem(
-                                            BadInputError::HasTab,
-                                            state.line,
-                                            state.column,
-                                        ),
-                                        state,
-                                    ));
-                                }
-                                '#' => {
-                                    // Check indentation to make sure we were indented enough
-                                    // before this comment began.
-                                    let progress =
-                                        Progress::from_lengths(start_bytes_len, state.bytes.len());
-                                    state = state
-                                        .check_indent_e(
-                                            arena,
-                                            min_indent,
-                                            indent_problem,
-                                            start_row,
-                                            start_col,
-                                        )
-                                        .map_err(|(fail, _)| {
-                                            (progress, fail, original_state.clone())
-                                        })?
-                                        .advance_without_indenting_e(1, space_problem)?;
-
-                                    // We're now parsing a line comment!
-                                    line_state = LineState::Comment;
-                                }
-                                _ => {
-                                    return if require_at_least_one && bytes_parsed <= 1 {
-                                        // We've parsed 1 char and it was not a space,
-                                        // but we require parsing at least one space!
-                                        Err((
-                                            NoProgress,
-                                            missing_space_problem(state.line, state.column),
-                                            state,
-                                        ))
-                                    } else {
-                                        // First make sure we were indented enough!
-                                        //
-                                        // (We only do this if we've encountered any newlines.
-                                        // Otherwise, we assume indentation is already correct.
-                                        // It's actively important for correctness that we skip
-                                        // this check if there are no newlines, because otherwise
-                                        // we would have false positives for single-line defs.)
-                                        let progress = Progress::from_lengths(
-                                            start_bytes_len,
-                                            state.bytes.len(),
-                                        );
-                                        if any_newlines {
-                                            state = state
-                                                .check_indent_e(
-                                                    arena,
-                                                    min_indent,
-                                                    indent_problem,
-                                                    start_row,
-                                                    start_col,
-                                                )
-                                                .map_err(|(fail, _)| {
-                                                    (progress, fail, original_state.clone())
-                                                })?;
-                                        }
-
-                                        Ok((progress, space_list.into_bump_slice(), state))
-                                    };
-                                }
-                            }
-                        }
-                        LineState::Comment => {
-                            match ch {
-                                ' ' => {
-                                    // If we're in a line comment, this won't affect indentation anyway.
-                                    state = state.advance_without_indenting_e(1, space_problem)?;
-
-                                    if comment_line_buf.len() == 1 {
-                                        match comment_line_buf.chars().next() {
-                                            Some('#') => {
-                                                // This is a comment begining with `## ` - that is,
-                                                // a doc comment.
-                                                //
-                                                // (The space is important; otherwise, this is not
-                                                // a doc comment, but rather something like a
-                                                // big separator block, e.g. ############)
-                                                line_state = LineState::DocComment;
-
-                                                // This is now the beginning of the doc comment.
-                                                comment_line_buf.clear();
-                                            }
-                                            _ => {
-                                                comment_line_buf.push(ch);
-                                            }
-                                        }
-                                    } else {
-                                        comment_line_buf.push(ch);
-                                    }
-                                }
-                                '\n' => {
-                                    state = state.newline_e(arena, space_problem)?;
-
-                                    match (comment_line_buf.len(), comment_line_buf.chars().next())
-                                    {
-                                        (1, Some('#')) => {
-                                            // This is a line with `##` - that is,
-                                            // a doc comment new line.
-                                            space_list.push(DocComment(""));
-                                            comment_line_buf = String::new_in(arena);
-
-                                            line_state = LineState::Normal;
-                                        }
-                                        _ => {
-                                            // This was a newline, so end this line comment.
-                                            space_list.push(LineComment(
-                                                comment_line_buf.into_bump_str(),
-                                            ));
-                                            comment_line_buf = String::new_in(arena);
-
-                                            line_state = LineState::Normal;
-                                        }
-                                    }
-                                }
-                                '\t' => {
-                                    return Err((
-                                        MadeProgress,
-                                        space_problem(
-                                            BadInputError::HasTab,
-                                            state.line,
-                                            state.column,
-                                        ),
-                                        state,
-                                    ));
-                                }
-                                nonblank => {
-                                    // Chars can have btye lengths of more than 1!
-                                    state = state.advance_without_indenting_e(
-                                        nonblank.len_utf8(),
-                                        space_problem,
-                                    )?;
-
-                                    comment_line_buf.push(nonblank);
-                                }
-                            }
-                        }
-                        LineState::DocComment => {
-                            match ch {
-                                ' ' => {
-                                    // If we're in a doc comment, this won't affect indentation anyway.
-                                    state = state.advance_without_indenting_e(1, space_problem)?;
-
-                                    comment_line_buf.push(ch);
-                                }
-                                '\n' => {
-                                    state = state.newline_e(arena, space_problem)?;
-
-                                    // This was a newline, so end this doc comment.
-                                    space_list.push(DocComment(comment_line_buf.into_bump_str()));
-                                    comment_line_buf = String::new_in(arena);
-
-                                    line_state = LineState::Normal;
-                                }
-                                '\t' => {
-                                    return Err((
-                                        MadeProgress,
-                                        space_problem(
-                                            BadInputError::HasTab,
-                                            state.line,
-                                            state.column,
-                                        ),
-                                        state,
-                                    ));
-                                }
-                                nonblank => {
-                                    state = state
-                                        .advance_without_indenting_e(utf8_len, space_problem)?;
-
-                                    comment_line_buf.push(nonblank);
-                                }
-                            }
-                        }
-                    }
-                }
-                Err(SyntaxError::BadUtf8) => {
-                    // If we hit an invalid UTF-8 character, bail out immediately.
-                    let progress = Progress::from_lengths(start_bytes_len, state.bytes.len());
-                    let row = state.line;
-                    let col = state.column;
-                    return state.fail(
-                        arena,
-                        progress,
-                        space_problem(BadInputError::BadUtf8, row, col),
-                    );
-                }
-                Err(_) => {
-                    if require_at_least_one && bytes_parsed == 0 {
-                        return Err((
-                            NoProgress,
-                            missing_space_problem(state.line, state.column),
-                            state,
-                        ));
-                    } else {
-                        let space_slice = space_list.into_bump_slice();
-
-                        // First make sure we were indented enough!
-                        //
-                        // (We only do this if we've encountered any newlines.
-                        // Otherwise, we assume indentation is already correct.
-                        // It's actively important for correctness that we skip
-                        // this check if there are no newlines, because otherwise
-                        // we would have false positives for single-line defs.)
-                        let progress = Progress::from_lengths(start_bytes_len, state.bytes.len());
-                        if any_newlines {
-                            return Ok((
-                                progress,
-                                space_slice,
-                                state
-                                    .check_indent_e(
-                                        arena,
-                                        min_indent,
-                                        indent_problem,
-                                        start_row,
-                                        start_col,
-                                    )
-                                    .map_err(|(fail, _)| (progress, fail, original_state))?,
-                            ));
-                        }
-
-                        return Ok((progress, space_slice, state));
-                    }
-                }
-            };
-        }
-
-        if require_at_least_one && original_state.bytes.len() == state.bytes.len() {
-            Err((
-                NoProgress,
-                missing_space_problem(state.line, state.column),
-                state,
-            ))
-        } else {
-            // First make sure we were indented enough!
-            //
-            // (We only do this if we've encountered any newlines.
-            // Otherwise, we assume indentation is already correct.
-            // It's actively important for correctness that we skip
-            // this check if there are no newlines, because otherwise
-            // we would have false positives for single-line defs.)
-            let progress = Progress::from_lengths(start_bytes_len, state.bytes.len());
-            if any_newlines {
-                state = state
-                    .check_indent_e(arena, min_indent, indent_problem, start_row, start_col)
-                    .map_err(|(fail, _)| (progress, fail, original_state))?;
-            }
-
-            Ok((progress, space_list.into_bump_slice(), state))
-        }
-    }
-}

From 9265cf82b9a3ab32257d9b8521e1ea500e996741 Mon Sep 17 00:00:00 2001
From: Folkert <folkert@folkertdev.nl>
Date: Fri, 12 Mar 2021 01:11:34 +0100
Subject: [PATCH 57/74] more cleanup

---
 compiler/parse/src/blankspace.rs | 75 ++++++++++++++++++++++++++----
 compiler/parse/src/expr.rs       | 33 +++++--------
 compiler/parse/src/parser.rs     | 79 --------------------------------
 3 files changed, 78 insertions(+), 109 deletions(-)

diff --git a/compiler/parse/src/blankspace.rs b/compiler/parse/src/blankspace.rs
index 4facf2daba..adcbd93896 100644
--- a/compiler/parse/src/blankspace.rs
+++ b/compiler/parse/src/blankspace.rs
@@ -3,7 +3,7 @@ use crate::ast::Spaceable;
 use crate::parser::{
     self, and, BadInputError, Col, Parser,
     Progress::{self, *},
-    Row, State, SyntaxError,
+    Row, State,
 };
 use bumpalo::collections::vec::Vec;
 use bumpalo::Bump;
@@ -150,15 +150,74 @@ where
     }
 }
 
-pub fn line_comment<'a>() -> impl Parser<'a, &'a str, SyntaxError<'a>> {
-    |_, state: State<'a>| match chomp_line_comment(state.bytes) {
-        Ok(comment) => {
-            let width = 1 + comment.len();
-            let state = state.advance_without_indenting(width + 1)?;
+pub fn spaces_till_end_of_line<'a, E: 'a>(
+    tab_problem: fn(Row, Col) -> E,
+) -> impl Parser<'a, Option<&'a str>, E> {
+    move |arena, mut state: State<'a>| {
+        let mut bytes = state.bytes;
+        let mut row = state.line;
+        let mut col = state.column;
 
-            Ok((MadeProgress, comment, state))
+        for c in bytes {
+            match c {
+                b' ' => {
+                    bytes = &bytes[1..];
+                    col += 1;
+                }
+                b'\n' => {
+                    bytes = &bytes[1..];
+                    row += 1;
+                    col = 0;
+
+                    state.line = row;
+                    state.column = col;
+                    state.bytes = bytes;
+                    state.is_indenting = true;
+
+                    return Ok((MadeProgress, None, state));
+                }
+                b'\r' => {
+                    bytes = &bytes[1..];
+                }
+                b'\t' => {
+                    return Err((
+                        MadeProgress,
+                        tab_problem(row, col),
+                        State {
+                            line: row,
+                            column: col,
+                            ..state
+                        },
+                    ))
+                }
+                b'#' => match chomp_line_comment(bytes) {
+                    Ok(comment) => {
+                        state.line += 1;
+
+                        state.column += col + comment.len() as u16;
+                        state.bytes = &bytes[comment.len()..];
+                        state.is_indenting = true;
+
+                        return Ok((MadeProgress, Some(comment), state));
+                    }
+                    Err(_) => unreachable!("we check the first character is a #"),
+                },
+                _ => break,
+            }
+        }
+
+        if state.column == col {
+            Ok((NoProgress, None, state))
+        } else {
+            Ok((
+                MadeProgress,
+                None,
+                State {
+                    column: col,
+                    ..state
+                },
+            ))
         }
-        Err(progress) => Err((progress, SyntaxError::ConditionFailed, state)),
     }
 }
 
diff --git a/compiler/parse/src/expr.rs b/compiler/parse/src/expr.rs
index b22458e4ed..eb214180a6 100644
--- a/compiler/parse/src/expr.rs
+++ b/compiler/parse/src/expr.rs
@@ -1,15 +1,14 @@
 use crate::ast::{AssignedField, CommentOrNewline, Def, Expr, Pattern, Spaceable, TypeAnnotation};
 use crate::blankspace::{
-    line_comment, space0_after_e, space0_around_ee, space0_before_e, space0_e, space1_e,
-    spaces_exactly_e,
+    space0_after_e, space0_around_ee, space0_before_e, space0_e, space1_e, spaces_exactly_e,
 };
 use crate::ident::{lowercase_ident, parse_ident_help, Ident};
 use crate::keyword;
 use crate::parser::{
-    self, allocated, and_then_with_indent_level, ascii_char, backtrackable, map, newline_char,
-    optional, sep_by1, sep_by1_e, specialize, specialize_ref, then, trailing_sep_by0, word1, word2,
-    EExpr, EInParens, ELambda, EPattern, ERecord, EString, Either, If, List, Number, ParseResult,
-    Parser, State, SyntaxError, Type, When,
+    self, allocated, and_then_with_indent_level, backtrackable, map, optional, sep_by1, sep_by1_e,
+    specialize, specialize_ref, then, trailing_sep_by0, word1, word2, EExpr, EInParens, ELambda,
+    EPattern, ERecord, EString, Either, If, List, Number, ParseResult, Parser, State, SyntaxError,
+    Type, When,
 };
 use crate::pattern::loc_closure_param;
 use crate::type_annotation;
@@ -812,7 +811,7 @@ pub fn def_help<'a>(min_indent: u16) -> impl Parser<'a, Def<'a>, EExpr<'a>> {
                 // see if there is a definition (assuming the preceding characters were a type
                 // annotation
                 let (_, opt_rest, state) = optional(and!(
-                    spaces_then_comment_or_newline_help(),
+                    spaces_till_end_of_line(),
                     body_at_indent_help(min_indent)
                 ))
                 .parse(arena, state)?;
@@ -867,20 +866,10 @@ fn pattern_help<'a>(min_indent: u16) -> impl Parser<'a, Located<Pattern<'a>>, EE
     )
 }
 
-fn spaces_then_comment_or_newline_help<'a>() -> impl Parser<'a, Option<&'a str>, EExpr<'a>> {
-    specialize_ref(
-        EExpr::Syntax,
-        skip_first!(
-            zero_or_more!(ascii_char(b' ')),
-            map!(
-                either!(newline_char(), line_comment()),
-                |either_comment_or_newline| match either_comment_or_newline {
-                    Either::First(_) => None,
-                    Either::Second(comment) => Some(comment),
-                }
-            )
-        ),
-    )
+fn spaces_till_end_of_line<'a>() -> impl Parser<'a, Option<&'a str>, EExpr<'a>> {
+    crate::blankspace::spaces_till_end_of_line(|r, c| {
+        EExpr::Space(parser::BadInputError::HasTab, r, c)
+    })
 }
 
 type Body<'a> = (Located<Pattern<'a>>, Located<Expr<'a>>);
@@ -1191,7 +1180,7 @@ fn parse_def_signature_help<'a>(
             |_progress, type_ann, indent_level| {
                 map(
                     optional(and!(
-                        backtrackable(spaces_then_comment_or_newline_help()),
+                        backtrackable(spaces_till_end_of_line()),
                         body_at_indent_help(indent_level)
                     )),
                     move |opt_body| (type_ann.clone(), opt_body),
diff --git a/compiler/parse/src/parser.rs b/compiler/parse/src/parser.rs
index e9deb66e96..605a4684f1 100644
--- a/compiler/parse/src/parser.rs
+++ b/compiler/parse/src/parser.rs
@@ -52,79 +52,11 @@ impl<'a> State<'a> {
         }
     }
 
-    pub fn check_indent(
-        self,
-        _arena: &'a Bump,
-        min_indent: u16,
-    ) -> Result<Self, (SyntaxError<'a>, Self)> {
-        if self.indent_col < min_indent {
-            Err((SyntaxError::OutdentedTooFar, self))
-        } else {
-            Ok(self)
-        }
-    }
-
-    pub fn check_indent_e<TE, E>(
-        self,
-        _arena: &'a Bump,
-        min_indent: u16,
-        to_error: TE,
-        row: Row,
-        col: Col,
-    ) -> Result<Self, (E, Self)>
-    where
-        TE: Fn(Row, Col) -> E,
-    {
-        if self.indent_col < min_indent {
-            Err((to_error(row, col), self))
-        } else {
-            Ok(self)
-        }
-    }
-
-    /// Returns the total number of bytes consumed since the parser began parsing.
-    ///
-    /// So if the parser has consumed 8 bytes, this function will return 8.
-    pub fn bytes_consumed(&self) -> usize {
-        self.original_len - self.bytes.len()
-    }
-
     /// Returns whether the parser has reached the end of the input
     pub fn has_reached_end(&self) -> bool {
         self.bytes.is_empty()
     }
 
-    /// Increments the line, then resets column, indent_col, and is_indenting.
-    /// Advances the input by 1, to consume the newline character.
-    pub fn newline(&self, arena: &'a Bump) -> Result<Self, (Progress, SyntaxError<'a>, Self)> {
-        self.newline_e(arena, |_, _, _| SyntaxError::TooManyLines)
-    }
-
-    pub fn newline_e<TE, E>(
-        &self,
-        arena: &'a Bump,
-        to_error: TE,
-    ) -> Result<Self, (Progress, E, Self)>
-    where
-        TE: Fn(BadInputError, Row, Col) -> E,
-    {
-        match self.line.checked_add(1) {
-            Some(line) => Ok(State {
-                bytes: &self.bytes[1..],
-                line,
-                column: 0,
-                indent_col: 0,
-                is_indenting: true,
-                original_len: self.original_len,
-            }),
-            None => Err((
-                Progress::NoProgress,
-                to_error(BadInputError::TooManyLines, self.line, self.column),
-                self.clone(),
-            )),
-        }
-    }
-
     /// Use advance_spaces to advance with indenting.
     /// This assumes we are *not* advancing with spaces, or at least that
     /// any spaces on the line were preceded by non-spaces - which would mean
@@ -1131,17 +1063,6 @@ pub fn ascii_char<'a>(expected: u8) -> impl Parser<'a, (), SyntaxError<'a>> {
     }
 }
 
-/// A single '\n' character.
-/// Use this instead of ascii_char('\n') because it properly handles
-/// incrementing the line number.
-pub fn newline_char<'a>() -> impl Parser<'a, (), SyntaxError<'a>> {
-    move |arena, state: State<'a>| match state.bytes.first() {
-        Some(b'\n') => Ok((Progress::MadeProgress, (), state.newline(arena)?)),
-        Some(_) => Err(unexpected(0, Attempting::Keyword, state)),
-        _ => Err(unexpected_eof(arena, state, 0)),
-    }
-}
-
 /// One or more ASCII hex digits. (Useful when parsing unicode escape codes,
 /// which must consist entirely of ASCII hex digits.)
 pub fn ascii_hex_digits<'a>() -> impl Parser<'a, &'a str, SyntaxError<'a>> {

From f5d3845b145d4371d2b7b8da28616369115be79d Mon Sep 17 00:00:00 2001
From: Folkert <folkert@folkertdev.nl>
Date: Fri, 12 Mar 2021 01:15:44 +0100
Subject: [PATCH 58/74] remove unused functions

---
 compiler/parse/src/blankspace.rs | 11 ++++-------
 compiler/parse/src/parser.rs     |  9 ---------
 2 files changed, 4 insertions(+), 16 deletions(-)

diff --git a/compiler/parse/src/blankspace.rs b/compiler/parse/src/blankspace.rs
index adcbd93896..9cbccc7579 100644
--- a/compiler/parse/src/blankspace.rs
+++ b/compiler/parse/src/blankspace.rs
@@ -153,7 +153,7 @@ where
 pub fn spaces_till_end_of_line<'a, E: 'a>(
     tab_problem: fn(Row, Col) -> E,
 ) -> impl Parser<'a, Option<&'a str>, E> {
-    move |arena, mut state: State<'a>| {
+    move |_, mut state: State<'a>| {
         let mut bytes = state.bytes;
         let mut row = state.line;
         let mut col = state.column;
@@ -253,7 +253,7 @@ fn chomp_line_comment<'a>(buffer: &'a [u8]) -> Result<&'a str, Progress> {
 pub fn spaces_exactly_e<'a>(spaces_expected: u16) -> impl Parser<'a, (), parser::EExpr<'a>> {
     use parser::EExpr;
 
-    move |arena: &'a Bump, state: State<'a>| {
+    move |_, state: State<'a>| {
         if spaces_expected == 0 {
             return Ok((NoProgress, (), state));
         }
@@ -265,11 +265,8 @@ pub fn spaces_exactly_e<'a>(spaces_expected: u16) -> impl Parser<'a, (), parser:
                 b' ' => {
                     spaces_seen += 1;
                     if spaces_seen == spaces_expected {
-                        let state = state.advance_spaces_e(
-                            arena,
-                            spaces_expected as usize,
-                            EExpr::IndentStart,
-                        )?;
+                        let state =
+                            state.advance_spaces_e(spaces_expected as usize, EExpr::IndentStart)?;
                         return Ok((MadeProgress, (), state));
                     }
                 }
diff --git a/compiler/parse/src/parser.rs b/compiler/parse/src/parser.rs
index 605a4684f1..50a3fb4724 100644
--- a/compiler/parse/src/parser.rs
+++ b/compiler/parse/src/parser.rs
@@ -103,19 +103,10 @@ impl<'a> State<'a> {
         }
     }
 
-    pub fn advance_spaces(
-        &self,
-        arena: &'a Bump,
-        spaces: usize,
-    ) -> Result<Self, (Progress, SyntaxError<'a>, Self)> {
-        self.advance_spaces_e(arena, spaces, |line, _| SyntaxError::LineTooLong(line))
-    }
-
     /// Advance the parser while also indenting as appropriate.
     /// This assumes we are only advancing with spaces, since they can indent.
     pub fn advance_spaces_e<TE, E>(
         &self,
-        arena: &'a Bump,
         spaces: usize,
         to_error: TE,
     ) -> Result<Self, (Progress, E, Self)>

From 4f58c792e632e78d08ed68e324f7d22d2e411c63 Mon Sep 17 00:00:00 2001
From: Folkert <folkert@folkertdev.nl>
Date: Fri, 12 Mar 2021 01:37:27 +0100
Subject: [PATCH 59/74] removing old stuff

---
 compiler/parse/src/blankspace.rs      |  46 +++-
 compiler/parse/src/parser.rs          | 333 +-------------------------
 compiler/parse/src/string_literal.rs  |   9 +-
 compiler/parse/src/type_annotation.rs |  62 +----
 compiler/reporting/src/error/parse.rs |  20 ++
 5 files changed, 85 insertions(+), 385 deletions(-)

diff --git a/compiler/parse/src/blankspace.rs b/compiler/parse/src/blankspace.rs
index 9cbccc7579..b4524e13e9 100644
--- a/compiler/parse/src/blankspace.rs
+++ b/compiler/parse/src/blankspace.rs
@@ -249,6 +249,50 @@ fn chomp_line_comment<'a>(buffer: &'a [u8]) -> Result<&'a str, Progress> {
     }
 }
 
+/// Advance the parser while also indenting as appropriate.
+/// This assumes we are only advancing with spaces, since they can indent.
+fn advance_spaces_e<'a, TE, E>(
+    state: &State<'a>,
+    spaces: usize,
+    to_error: TE,
+) -> Result<State<'a>, (Progress, E, State<'a>)>
+where
+    TE: Fn(Row, Col) -> E,
+{
+    match (state.column as usize).checked_add(spaces) {
+        Some(column_usize) if column_usize <= u16::MAX as usize => {
+            // Spaces don't affect is_indenting; if we were previously indneting,
+            // we still are, and if we already finished indenting, we're still done.
+            let is_indenting = state.is_indenting;
+
+            // If we're indenting, spaces indent us further.
+            let indent_col = if is_indenting {
+                // This doesn't need to be checked_add because it's always true that
+                // indent_col <= col, so if this could possibly overflow, we would
+                // already have errored out from the column calculation.
+                //
+                // Leaving debug assertions in case this invariant someday disappers.
+                debug_assert!(u16::MAX - state.indent_col >= spaces as u16);
+                debug_assert!(spaces <= u16::MAX as usize);
+
+                state.indent_col + spaces as u16
+            } else {
+                state.indent_col
+            };
+
+            Ok(State {
+                bytes: &state.bytes[spaces..],
+                line: state.line,
+                column: column_usize as u16,
+                indent_col,
+                is_indenting,
+                original_len: state.original_len,
+            })
+        }
+        _ => Err(crate::parser::line_too_long_e(state.clone(), to_error)),
+    }
+}
+
 #[inline(always)]
 pub fn spaces_exactly_e<'a>(spaces_expected: u16) -> impl Parser<'a, (), parser::EExpr<'a>> {
     use parser::EExpr;
@@ -266,7 +310,7 @@ pub fn spaces_exactly_e<'a>(spaces_expected: u16) -> impl Parser<'a, (), parser:
                     spaces_seen += 1;
                     if spaces_seen == spaces_expected {
                         let state =
-                            state.advance_spaces_e(spaces_expected as usize, EExpr::IndentStart)?;
+                            advance_spaces_e(&state, spaces_expected as usize, EExpr::IndentStart)?;
                         return Ok((MadeProgress, (), state));
                     }
                 }
diff --git a/compiler/parse/src/parser.rs b/compiler/parse/src/parser.rs
index 50a3fb4724..274b939977 100644
--- a/compiler/parse/src/parser.rs
+++ b/compiler/parse/src/parser.rs
@@ -1,11 +1,9 @@
 use crate::ast::Attempting;
 use bumpalo::collections::vec::Vec;
 use bumpalo::Bump;
-use encode_unicode::CharExt;
 use roc_region::all::{Located, Region};
 use std::fmt;
 use std::str::from_utf8;
-use std::{char, u16};
 use Progress::*;
 
 /// A position in a source file.
@@ -103,50 +101,6 @@ impl<'a> State<'a> {
         }
     }
 
-    /// Advance the parser while also indenting as appropriate.
-    /// This assumes we are only advancing with spaces, since they can indent.
-    pub fn advance_spaces_e<TE, E>(
-        &self,
-        spaces: usize,
-        to_error: TE,
-    ) -> Result<Self, (Progress, E, Self)>
-    where
-        TE: Fn(Row, Col) -> E,
-    {
-        match (self.column as usize).checked_add(spaces) {
-            Some(column_usize) if column_usize <= u16::MAX as usize => {
-                // Spaces don't affect is_indenting; if we were previously indneting,
-                // we still are, and if we already finished indenting, we're still done.
-                let is_indenting = self.is_indenting;
-
-                // If we're indenting, spaces indent us further.
-                let indent_col = if is_indenting {
-                    // This doesn't need to be checked_add because it's always true that
-                    // indent_col <= col, so if this could possibly overflow, we would
-                    // already have errored out from the column calculation.
-                    //
-                    // Leaving debug assertions in case this invariant someday disappers.
-                    debug_assert!(u16::MAX - self.indent_col >= spaces as u16);
-                    debug_assert!(spaces <= u16::MAX as usize);
-
-                    self.indent_col + spaces as u16
-                } else {
-                    self.indent_col
-                };
-
-                Ok(State {
-                    bytes: &self.bytes[spaces..],
-                    line: self.line,
-                    column: column_usize as u16,
-                    indent_col,
-                    is_indenting,
-                    original_len: self.original_len,
-                })
-            }
-            _ => Err(line_too_long_e(self.clone(), to_error)),
-        }
-    }
-
     /// Returns a Region corresponding to the current state, but
     /// with the end_col advanced by the given amount. This is
     /// useful when parsing something "manually" (using input.chars())
@@ -500,6 +454,7 @@ pub enum EString<'a> {
     EndlessMulti(Row, Col),
     UnknownEscape(Row, Col),
     Format(&'a SyntaxError<'a>, Row, Col),
+    FormatEnd(Row, Col),
 }
 
 #[derive(Debug, Clone, PartialEq, Eq)]
@@ -953,62 +908,8 @@ where
     }
 }
 
-pub fn unexpected_eof<'a>(
-    _arena: &'a Bump,
-    state: State<'a>,
-    chars_consumed: usize,
-) -> (Progress, SyntaxError<'a>, State<'a>) {
-    checked_unexpected(state, chars_consumed, SyntaxError::Eof)
-}
-
-pub fn unexpected(
-    chars_consumed: usize,
-    _attempting: Attempting,
-    state: State,
-) -> (Progress, SyntaxError, State) {
-    // NOTE state is the last argument because chars_consumed often depends on the state's fields
-    // having state be the final argument prevents borrowing issues
-    checked_unexpected(state, chars_consumed, |region| {
-        SyntaxError::Unexpected(region)
-    })
-}
-
-/// Check for line overflow, then compute a new Region based on chars_consumed
-/// and provide it as a way to construct a Problem.
-/// If maximum line length was exceeded, return a Problem indicating as much.
-#[inline(always)]
-fn checked_unexpected<'a, F>(
-    state: State<'a>,
-    chars_consumed: usize,
-    problem_from_region: F,
-) -> (Progress, SyntaxError<'a>, State<'a>)
-where
-    F: FnOnce(Region) -> SyntaxError<'a>,
-{
-    match (state.column as usize).checked_add(chars_consumed) {
-        // Crucially, this is < u16::MAX and not <= u16::MAX. This means if
-        // column ever gets set to u16::MAX, we will automatically bail out
-        // with LineTooLong - which is exactly what we want! Once a line has
-        // been discovered to be too long, we don't want to parse anything else
-        // until that's fixed.
-        Some(end_col) if end_col < u16::MAX as usize => {
-            let region = Region {
-                start_col: state.column,
-                end_col: end_col as u16,
-                start_line: state.line,
-                end_line: state.line,
-            };
-
-            (Progress::NoProgress, problem_from_region(region), state)
-        }
-        _ => {
-            let (_progress, fail, state) = line_too_long(state);
-            (Progress::NoProgress, fail, state)
-        }
-    }
-}
-
-fn line_too_long_e<TE, E>(state: State, to_error: TE) -> (Progress, E, State)
+// TODO remove
+pub fn line_too_long_e<TE, E>(state: State, to_error: TE) -> (Progress, E, State)
 where
     TE: Fn(Row, Col) -> E,
 {
@@ -1033,133 +934,6 @@ where
     (Progress::NoProgress, problem, state)
 }
 
-fn line_too_long(state: State) -> (Progress, SyntaxError, State) {
-    line_too_long_e(state, |line, _| SyntaxError::LineTooLong(line))
-}
-
-/// A single ASCII char that isn't a newline.
-/// (For newlines, use newline_char(), which handles line numbers)
-pub fn ascii_char<'a>(expected: u8) -> impl Parser<'a, (), SyntaxError<'a>> {
-    // Make sure this really is not a newline!
-    debug_assert_ne!(expected, b'\n');
-
-    move |arena, state: State<'a>| match state.bytes.first() {
-        Some(&actual) if expected == actual => Ok((
-            Progress::MadeProgress,
-            (),
-            state.advance_without_indenting(1)?,
-        )),
-        Some(_) => Err(unexpected(0, Attempting::Keyword, state)),
-        _ => Err(unexpected_eof(arena, state, 0)),
-    }
-}
-
-/// One or more ASCII hex digits. (Useful when parsing unicode escape codes,
-/// which must consist entirely of ASCII hex digits.)
-pub fn ascii_hex_digits<'a>() -> impl Parser<'a, &'a str, SyntaxError<'a>> {
-    move |arena, state: State<'a>| {
-        let mut buf = bumpalo::collections::String::new_in(arena);
-
-        for &byte in state.bytes.iter() {
-            if (byte as char).is_ascii_hexdigit() {
-                buf.push(byte as char);
-            } else if buf.is_empty() {
-                // We didn't find any hex digits!
-                return Err(unexpected(0, Attempting::Keyword, state));
-            } else {
-                let state = state.advance_without_indenting(buf.len())?;
-
-                return Ok((Progress::MadeProgress, buf.into_bump_str(), state));
-            }
-        }
-
-        Err(unexpected_eof(arena, state, 0))
-    }
-}
-
-/// A single UTF-8-encoded char. This will both parse *and* validate that the
-/// char is valid UTF-8, but it will *not* advance the state.
-pub fn peek_utf8_char<'a>(state: &State) -> Result<(char, usize), SyntaxError<'a>> {
-    if !state.bytes.is_empty() {
-        match char::from_utf8_slice_start(state.bytes) {
-            Ok((ch, len_utf8)) => Ok((ch, len_utf8)),
-            Err(_) => Err(SyntaxError::BadUtf8),
-        }
-    } else {
-        Err(SyntaxError::Eof(
-            Region::zero(), /* TODO get a better region */
-        ))
-    }
-}
-
-/// A single UTF-8-encoded char. This will both parse *and* validate that the
-/// char is valid UTF-8, but it will *not* advance the state.
-pub fn peek_utf8_char_e<EOF, TE, E>(
-    state: &State,
-    end_of_file: EOF,
-    to_error: TE,
-) -> Result<(char, usize), E>
-where
-    TE: Fn(BadInputError, Row, Col) -> E,
-    EOF: Fn(Row, Col) -> E,
-{
-    if !state.bytes.is_empty() {
-        match char::from_utf8_slice_start(state.bytes) {
-            Ok((ch, len_utf8)) => Ok((ch, len_utf8)),
-            Err(_) => Err(to_error(BadInputError::BadUtf8, state.line, state.column)),
-        }
-    } else {
-        Err(end_of_file(state.line, state.column))
-    }
-}
-
-/// A single UTF-8-encoded char, with an offset. This will both parse *and*
-/// validate that the char is valid UTF-8, but it will *not* advance the state.
-pub fn peek_utf8_char_at<'a>(
-    state: &State,
-    offset: usize,
-) -> Result<(char, usize), SyntaxError<'a>> {
-    if state.bytes.len() > offset {
-        let bytes = &state.bytes[offset..];
-
-        match char::from_utf8_slice_start(bytes) {
-            Ok((ch, len_utf8)) => Ok((ch, len_utf8)),
-            Err(_) => Err(SyntaxError::BadUtf8),
-        }
-    } else {
-        Err(SyntaxError::Eof(
-            Region::zero(), /* TODO get a better region */
-        ))
-    }
-}
-
-pub fn keyword<'a>(
-    keyword: &'static str,
-    _min_indent: u16,
-) -> impl Parser<'a, (), SyntaxError<'a>> {
-    move |arena, state: State<'a>| {
-        let initial_state = state.clone();
-        // first parse the keyword characters
-        let (_, _, after_keyword_state) = ascii_string(keyword).parse(arena, state)?;
-
-        // then we must have at least one space character
-        // TODO this is potentially wasteful if there are a lot of spaces
-        match peek_utf8_char(&after_keyword_state) {
-            Ok((next, _width)) if next == ' ' || next == '#' || next == '\n' => {
-                // give back the state after parsing the keyword, but before the whitespace
-                // that way we can attach the whitespace to whatever follows
-                Ok((MadeProgress, (), after_keyword_state))
-            }
-            _ => {
-                // this is not a keyword, maybe it's `whence` or `iffy`
-                // anyway, make no progress and return the initial state
-                // so we can try something else
-                Err((NoProgress, SyntaxError::ConditionFailed, initial_state))
-            }
-        }
-    }
-}
-
 pub fn keyword_e<'a, ToError, E>(keyword: &'static str, if_error: ToError) -> impl Parser<'a, (), E>
 where
     ToError: Fn(Row, Col) -> E,
@@ -1190,32 +964,6 @@ where
     }
 }
 
-/// A hardcoded string with no newlines, consisting only of ASCII characters
-pub fn ascii_string<'a>(keyword: &'static str) -> impl Parser<'a, (), SyntaxError<'a>> {
-    // Verify that this really is exclusively ASCII characters.
-    // The `unsafe` block in this function relies upon this assumption!
-    //
-    // Also, this can't have newlines because we don't attempt to advance
-    // the row in the state, only the column.
-    debug_assert!(keyword.chars().all(|ch| ch.len_utf8() == 1 && ch != '\n'));
-
-    move |_arena, state: State<'a>| {
-        let len = keyword.len();
-
-        // TODO do this comparison in one SIMD instruction (on supported systems)
-        if state.bytes.starts_with(keyword.as_bytes()) {
-            Ok((
-                Progress::MadeProgress,
-                (),
-                state.advance_without_indenting(len)?,
-            ))
-        } else {
-            let (_, fail, state) = unexpected(len, Attempting::Keyword, state);
-            Err((NoProgress, fail, state))
-        }
-    }
-}
-
 /// Parse zero or more values separated by a delimiter (e.g. a comma) whose
 /// values are discarded
 pub fn sep_by0<'a, P, D, Val, Error>(
@@ -1483,21 +1231,6 @@ pub fn fail_when_progress<T, E>(
     }
 }
 
-pub fn satisfies<'a, P, A, F>(parser: P, predicate: F) -> impl Parser<'a, A, SyntaxError<'a>>
-where
-    P: Parser<'a, A, SyntaxError<'a>>,
-    F: Fn(&A) -> bool,
-{
-    move |arena: &'a Bump, state: State<'a>| match parser.parse(arena, state.clone()) {
-        Ok((progress, output, next_state)) if predicate(&output) => {
-            Ok((progress, output, next_state))
-        }
-        Ok((progress, _, _)) | Err((progress, _, _)) => {
-            Err((progress, SyntaxError::ConditionFailed, state))
-        }
-    }
-}
-
 pub fn optional<'a, P, T, E>(parser: P) -> impl Parser<'a, Option<T>, E>
 where
     P: Parser<'a, T, E>,
@@ -1921,30 +1654,6 @@ macro_rules! word1_check_indent {
     };
 }
 
-#[allow(dead_code)]
-fn in_context<'a, AddContext, P1, P2, Start, A, X, Y>(
-    add_context: AddContext,
-    parser_start: P1,
-    parser_rest: P2,
-) -> impl Parser<'a, A, Y>
-where
-    AddContext: Fn(X, Row, Col) -> Y,
-    P1: Parser<'a, Start, Y>,
-    P2: Parser<'a, A, X>,
-    Y: 'a,
-{
-    move |arena, state| {
-        let (_, _, state) = parser_start.parse(arena, state)?;
-
-        match parser_rest.parse(arena, state) {
-            Ok((progress, value, state)) => Ok((progress, value, state)),
-            Err((progress, fail, state)) => {
-                Err((progress, add_context(fail, state.line, state.column), state))
-            }
-        }
-    }
-}
-
 #[macro_export]
 macro_rules! map {
     ($parser:expr, $transform:expr) => {
@@ -2025,42 +1734,6 @@ macro_rules! zero_or_more {
     };
 }
 
-#[macro_export]
-macro_rules! one_or_more {
-    ($parser:expr) => {
-        move |arena, state: State<'a>| {
-            use bumpalo::collections::Vec;
-
-            match $parser.parse(arena, state) {
-                Ok((_, first_output, next_state)) => {
-                    let mut state = next_state;
-                    let mut buf = Vec::with_capacity_in(1, arena);
-
-                    buf.push(first_output);
-
-                    loop {
-                        match $parser.parse(arena, state) {
-                            Ok((_, next_output, next_state)) => {
-                                state = next_state;
-                                buf.push(next_output);
-                            }
-                            Err((progress, fail, old_state)) => {
-                                return $crate::parser::fail_when_progress(
-                                    progress, fail, buf, old_state,
-                                )
-                            }
-                        }
-                    }
-                }
-                Err((progress, _, new_state)) => {
-                    debug_assert_eq!(progress, NoProgress, "{:?}", &new_state);
-                    Err($crate::parser::unexpected_eof(arena, new_state, 0))
-                }
-            }
-        }
-    };
-}
-
 #[macro_export]
 macro_rules! one_or_more_e {
     ($parser:expr, $to_error:expr) => {
diff --git a/compiler/parse/src/string_literal.rs b/compiler/parse/src/string_literal.rs
index 6c5d3e1564..f68cf849d1 100644
--- a/compiler/parse/src/string_literal.rs
+++ b/compiler/parse/src/string_literal.rs
@@ -2,8 +2,7 @@ use crate::ast::{EscapedChar, StrLiteral, StrSegment};
 use crate::expr;
 use crate::parser::Progress::*;
 use crate::parser::{
-    allocated, ascii_char, loc, parse_utf8, specialize_ref, word1, BadInputError, EString, Parser,
-    State,
+    allocated, loc, parse_utf8, specialize_ref, word1, BadInputError, EString, Parser, State,
 };
 use bumpalo::collections::vec::Vec;
 use bumpalo::Bump;
@@ -233,9 +232,9 @@ pub fn parse<'a>() -> impl Parser<'a, StrLiteral<'a>, EString<'a>> {
                             // Parse an arbitrary expression, then give a
                             // canonicalization error if that expression variant
                             // is not allowed inside a string interpolation.
-                            let (_progress, loc_expr, new_state) = specialize_ref(
-                                EString::Format,
-                                skip_second!(loc(allocated(expr::expr(0))), ascii_char(b')')),
+                            let (_progress, loc_expr, new_state) = skip_second!(
+                                specialize_ref(EString::Format, loc(allocated(expr::expr(0)))),
+                                word1(b')', EString::FormatEnd)
                             )
                             .parse(arena, state)?;
 
diff --git a/compiler/parse/src/type_annotation.rs b/compiler/parse/src/type_annotation.rs
index bba35326bc..cd9b2d8ea4 100644
--- a/compiler/parse/src/type_annotation.rs
+++ b/compiler/parse/src/type_annotation.rs
@@ -2,8 +2,8 @@ use crate::ast::{AssignedField, Tag, TypeAnnotation};
 use crate::blankspace::{space0_around_ee, space0_before_e, space0_e};
 use crate::keyword;
 use crate::parser::{
-    allocated, backtrackable, not_e, optional, peek_utf8_char_e, specialize, specialize_ref, word1,
-    word2, ParseResult, Parser,
+    allocated, backtrackable, not_e, optional, specialize, specialize_ref, word1, word2,
+    ParseResult, Parser,
     Progress::{self, *},
     State, SyntaxError, TApply, TInParens, TRecord, TTagUnion, TVariable, Type,
 };
@@ -120,7 +120,7 @@ fn loc_applied_arg<'a>(min_indent: u16) -> impl Parser<'a, Located<TypeAnnotatio
                 // Once we hit an "as", stop parsing args
                 // and roll back parsing of preceding spaces
                 not_e(
-                    crate::parser::keyword(keyword::AS, min_indent),
+                    crate::parser::keyword_e(keyword::AS, Type::TStart),
                     Type::TStart
                 ),
                 one_of!(
@@ -550,54 +550,18 @@ fn parse_concrete_type<'a>(
 
 fn parse_type_variable<'a>(
     arena: &'a Bump,
-    mut state: State<'a>,
+    state: State<'a>,
 ) -> ParseResult<'a, TypeAnnotation<'a>, TVariable> {
-    let mut buf = String::new_in(arena);
+    match crate::ident::lowercase_ident().parse(arena, state) {
+        Ok((_, name, state)) => {
+            let answer = TypeAnnotation::BoundVariable(name);
 
-    let start_bytes_len = state.bytes.len();
-
-    match peek_utf8_char_e(&state, TVariable::StartNotLowercase, TVariable::Space) {
-        Ok((first_letter, bytes_parsed)) => {
-            // Type variables must start with a lowercase letter.
-            if first_letter.is_alphabetic() && first_letter.is_lowercase() {
-                buf.push(first_letter);
-            } else {
-                return Err((
-                    NoProgress,
-                    TVariable::StartNotLowercase(state.line, state.column),
-                    state,
-                ));
-            }
-
-            state = state.advance_without_indenting_e(bytes_parsed, TVariable::Space)?;
+            Ok((MadeProgress, answer, state))
         }
-        Err(reason) => return Err((NoProgress, reason, state)),
+        Err((progress, _, state)) => Err((
+            progress,
+            TVariable::StartNotLowercase(state.line, state.column),
+            state,
+        )),
     }
-
-    while !state.bytes.is_empty() {
-        match peek_utf8_char_e(&state, TVariable::End, TVariable::Space) {
-            Ok((ch, bytes_parsed)) => {
-                // After the first character, only these are allowed:
-                //
-                // * Unicode alphabetic chars - you might name a variable `鹏` if that's clear to your readers
-                // * ASCII digits - e.g. `1` but not `¾`, both of which pass .is_numeric()
-                if ch.is_alphabetic() || ch.is_ascii_digit() {
-                    buf.push(ch);
-                } else {
-                    // This must be the end of the type. We're done!
-                    break;
-                }
-
-                state = state.advance_without_indenting_e(bytes_parsed, TVariable::Space)?;
-            }
-            Err(reason) => {
-                return state.fail(arena, MadeProgress, reason);
-            }
-        }
-    }
-
-    let answer = TypeAnnotation::BoundVariable(buf.into_bump_str());
-
-    let progress = Progress::from_lengths(start_bytes_len, state.bytes.len());
-    Ok((progress, answer, state))
 }
diff --git a/compiler/reporting/src/error/parse.rs b/compiler/reporting/src/error/parse.rs
index 8fc3ffc88a..42402bad9d 100644
--- a/compiler/reporting/src/error/parse.rs
+++ b/compiler/reporting/src/error/parse.rs
@@ -740,6 +740,26 @@ fn to_str_report<'a>(
                 title: "WEIRD CODE POINT".to_string(),
             }
         }
+        EString::FormatEnd(row, col) => {
+            let surroundings = Region::from_rows_cols(start_row, start_col, row, col);
+            let region = Region::from_row_col(row, col);
+
+            let doc = alloc.stack(vec![
+                alloc.reflow(r"I cannot find the end of this format expression:"),
+                alloc.region_with_subregion(surroundings, region),
+                alloc.concat(vec![
+                    alloc.reflow(r"You could change it to something like "),
+                    alloc.parser_suggestion("\"The count is \\(count\\)\""),
+                    alloc.reflow("."),
+                ]),
+            ]);
+
+            Report {
+                filename,
+                doc,
+                title: "ENDLESS FORMAT".to_string(),
+            }
+        }
         EString::EndlessSingle(row, col) => {
             let surroundings = Region::from_rows_cols(start_row, start_col, row, col);
             let region = Region::from_row_col(row, col);

From 98024b2a21b75af9144738edb7fb28a908622ac2 Mon Sep 17 00:00:00 2001
From: Folkert <folkert@folkertdev.nl>
Date: Fri, 12 Mar 2021 01:49:09 +0100
Subject: [PATCH 60/74] parse tag names in types

---
 compiler/parse/src/expr.rs            |   2 +-
 compiler/parse/src/ident.rs           |  20 ++++++
 compiler/parse/src/parser.rs          |   2 +-
 compiler/parse/src/type_annotation.rs | 100 +-------------------------
 4 files changed, 25 insertions(+), 99 deletions(-)

diff --git a/compiler/parse/src/expr.rs b/compiler/parse/src/expr.rs
index eb214180a6..7bf9b8393d 100644
--- a/compiler/parse/src/expr.rs
+++ b/compiler/parse/src/expr.rs
@@ -1692,7 +1692,7 @@ fn unary_negate_function_arg_help<'a>(
 fn loc_function_args_help<'a>(
     min_indent: u16,
 ) -> impl Parser<'a, Vec<'a, Located<Expr<'a>>>, EExpr<'a>> {
-    one_or_more_e!(
+    one_or_more!(
         move |arena: &'a Bump, s| {
             map!(
                 and!(
diff --git a/compiler/parse/src/ident.rs b/compiler/parse/src/ident.rs
index 402d20386f..9a239456e9 100644
--- a/compiler/parse/src/ident.rs
+++ b/compiler/parse/src/ident.rs
@@ -75,6 +75,26 @@ pub fn lowercase_ident<'a>() -> impl Parser<'a, &'a str, ()> {
     }
 }
 
+pub fn tag_name<'a>() -> impl Parser<'a, &'a str, ()> {
+    move |arena, state: State<'a>| {
+        if state.bytes.starts_with(b"@") {
+            match chomp_private_tag(state.bytes, state.line, state.column) {
+                Err(BadIdent::Start(_, _)) => Err((NoProgress, (), state)),
+                Err(_) => Err((MadeProgress, (), state)),
+                Ok(ident) => {
+                    let width = ident.len();
+                    match state.advance_without_indenting_ee(width, |_, _| ()) {
+                        Ok(state) => Ok((MadeProgress, ident, state)),
+                        Err(bad) => Err(bad),
+                    }
+                }
+            }
+        } else {
+            uppercase_ident().parse(arena, state)
+        }
+    }
+}
+
 /// This could be:
 ///
 /// * A module name
diff --git a/compiler/parse/src/parser.rs b/compiler/parse/src/parser.rs
index 274b939977..96574653c9 100644
--- a/compiler/parse/src/parser.rs
+++ b/compiler/parse/src/parser.rs
@@ -1735,7 +1735,7 @@ macro_rules! zero_or_more {
 }
 
 #[macro_export]
-macro_rules! one_or_more_e {
+macro_rules! one_or_more {
     ($parser:expr, $to_error:expr) => {
         move |arena, state: State<'a>| {
             use bumpalo::collections::Vec;
diff --git a/compiler/parse/src/type_annotation.rs b/compiler/parse/src/type_annotation.rs
index cd9b2d8ea4..cb81688734 100644
--- a/compiler/parse/src/type_annotation.rs
+++ b/compiler/parse/src/type_annotation.rs
@@ -7,7 +7,6 @@ use crate::parser::{
     Progress::{self, *},
     State, SyntaxError, TApply, TInParens, TRecord, TTagUnion, TVariable, Type,
 };
-use bumpalo::collections::string::String;
 use bumpalo::collections::vec::Vec;
 use bumpalo::Bump;
 use roc_region::all::{Located, Region};
@@ -191,102 +190,9 @@ where
     F: Fn(Row, Col) -> E,
     E: 'a,
 {
-    use encode_unicode::CharExt;
-
-    move |arena, mut state: State<'a>| {
-        let mut buf;
-
-        match char::from_utf8_slice_start(state.bytes) {
-            Ok((first_letter, bytes_parsed)) => match first_letter {
-                '@' => {
-                    debug_assert_eq!(bytes_parsed, 1);
-
-                    // parsing a private tag name
-                    match char::from_utf8_slice_start(&state.bytes[1..]) {
-                        Ok((second_letter, bytes_parsed_2)) if second_letter.is_uppercase() => {
-                            let total_parsed = bytes_parsed + bytes_parsed_2;
-
-                            buf = String::with_capacity_in(total_parsed, arena);
-
-                            buf.push('@');
-                            buf.push(second_letter);
-
-                            state = state.advance_without_indenting(total_parsed).map_err(
-                                |(progress, _, state)| {
-                                    (progress, to_problem(state.line, state.column), state)
-                                },
-                            )?;
-                        }
-                        _ => {
-                            // important for error messages
-                            state = state.advance_without_indenting(bytes_parsed).map_err(
-                                |(progress, _, state)| {
-                                    (progress, to_problem(state.line, state.column), state)
-                                },
-                            )?;
-
-                            let row = state.line;
-                            let col = state.column;
-                            return state.fail(arena, MadeProgress, to_problem(row, col));
-                        }
-                    }
-                }
-
-                _ if first_letter.is_uppercase() => {
-                    buf = String::with_capacity_in(1, arena);
-
-                    buf.push(first_letter);
-
-                    state = state.advance_without_indenting(bytes_parsed).map_err(
-                        |(progress, _, state)| {
-                            (progress, to_problem(state.line, state.column), state)
-                        },
-                    )?;
-                }
-
-                _ => {
-                    let row = state.line;
-                    let col = state.column;
-                    return state.fail(arena, NoProgress, to_problem(row, col));
-                }
-            },
-            Err(_) => {
-                let row = state.line;
-                let col = state.column;
-                return state.fail(arena, NoProgress, to_problem(row, col));
-            }
-        };
-
-        while !state.bytes.is_empty() {
-            match char::from_utf8_slice_start(state.bytes) {
-                Ok((ch, bytes_parsed)) => {
-                    // After the first character, only these are allowed:
-                    //
-                    // * Unicode alphabetic chars - you might include `鹏` if that's clear to your readers
-                    // * ASCII digits - e.g. `1` but not `¾`, both of which pass .is_numeric()
-                    // * A ':' indicating the end of the field
-                    if ch.is_alphabetic() || ch.is_ascii_digit() {
-                        buf.push(ch);
-
-                        state = state.advance_without_indenting(bytes_parsed).map_err(
-                            |(progress, _, state)| {
-                                (progress, to_problem(state.line, state.column), state)
-                            },
-                        )?;
-                    } else {
-                        // This is the end of the field. We're done!
-                        break;
-                    }
-                }
-                Err(_) => {
-                    let row = state.line;
-                    let col = state.column;
-                    return state.fail(arena, MadeProgress, to_problem(row, col));
-                }
-            };
-        }
-
-        Ok((MadeProgress, buf.into_bump_str(), state))
+    move |arena, state: State<'a>| match crate::ident::tag_name().parse(arena, state) {
+        Ok(good) => Ok(good),
+        Err((progress, _, state)) => Err((progress, to_problem(state.line, state.column), state)),
     }
 }
 

From 5e4db62c464f6016710fc6b557b25a00bac79ae9 Mon Sep 17 00:00:00 2001
From: Folkert <folkert@folkertdev.nl>
Date: Fri, 12 Mar 2021 02:09:48 +0100
Subject: [PATCH 61/74] remove Attempting and more

---
 compiler/parse/src/ast.rs            | 27 ----------
 compiler/parse/src/blankspace.rs     |  3 +-
 compiler/parse/src/module.rs         | 14 +++++-
 compiler/parse/src/number_literal.rs | 74 +++++++++++-----------------
 compiler/parse/src/parser.rs         | 58 +---------------------
 compiler/parse/src/string_literal.rs |  6 +--
 6 files changed, 46 insertions(+), 136 deletions(-)

diff --git a/compiler/parse/src/ast.rs b/compiler/parse/src/ast.rs
index 86b35524bf..bc0e0d1259 100644
--- a/compiler/parse/src/ast.rs
+++ b/compiler/parse/src/ast.rs
@@ -589,33 +589,6 @@ impl<'a> Spaceable<'a> for Def<'a> {
     }
 }
 
-/// What we're currently attempting to parse, e.g.
-/// "currently attempting to parse a list." This helps error messages!
-#[derive(Debug, Clone, Copy, PartialEq, Eq)]
-pub enum Attempting {
-    LineComment,
-    List,
-    Keyword,
-    StrLiteral,
-    RecordLiteral,
-    RecordFieldLabel,
-    InterpolatedString,
-    NumberLiteral,
-    UnicodeEscape,
-    ClosureParams,
-    ClosureBody,
-    Def,
-    Module,
-    Record,
-    Identifier,
-    HexDigit,
-    ConcreteType,
-    TypeVariable,
-    WhenCondition,
-    WhenBranch,
-    TODO,
-}
-
 impl<'a> Expr<'a> {
     pub fn loc_ref(&'a self, region: Region) -> Loc<&'a Self> {
         Loc {
diff --git a/compiler/parse/src/blankspace.rs b/compiler/parse/src/blankspace.rs
index b4524e13e9..7e05ef6d9d 100644
--- a/compiler/parse/src/blankspace.rs
+++ b/compiler/parse/src/blankspace.rs
@@ -275,7 +275,8 @@ where
                 debug_assert!(u16::MAX - state.indent_col >= spaces as u16);
                 debug_assert!(spaces <= u16::MAX as usize);
 
-                state.indent_col + spaces as u16
+                // state.indent_col + spaces as u16
+                state.indent_col
             } else {
                 state.indent_col
             };
diff --git a/compiler/parse/src/module.rs b/compiler/parse/src/module.rs
index 0068ae6933..39058ff686 100644
--- a/compiler/parse/src/module.rs
+++ b/compiler/parse/src/module.rs
@@ -7,8 +7,8 @@ use crate::header::{
 use crate::ident::{lowercase_ident, unqualified_ident, uppercase_ident};
 use crate::parser::Progress::{self, *};
 use crate::parser::{
-    backtrackable, end_of_file, specialize, word1, Col, EEffects, EExposes, EHeader, EImports,
-    EPackages, EProvides, ERequires, ETypedIdent, Parser, Row, State, SyntaxError,
+    backtrackable, specialize, word1, Col, EEffects, EExposes, EHeader, EImports, EPackages,
+    EProvides, ERequires, ETypedIdent, Parser, Row, State, SyntaxError,
 };
 use crate::string_literal;
 use crate::type_annotation;
@@ -249,6 +249,16 @@ fn platform_header<'a>() -> impl Parser<'a, PlatformHeader<'a>, EHeader<'a>> {
     }
 }
 
+fn end_of_file<'a>() -> impl Parser<'a, (), SyntaxError<'a>> {
+    |_arena, state: State<'a>| {
+        if state.has_reached_end() {
+            Ok((NoProgress, (), state))
+        } else {
+            Err((NoProgress, SyntaxError::ConditionFailed, state))
+        }
+    }
+}
+
 #[inline(always)]
 pub fn module_defs<'a>() -> impl Parser<'a, Vec<'a, Located<Def<'a>>>, SyntaxError<'a>> {
     use crate::parser::EExpr;
diff --git a/compiler/parse/src/number_literal.rs b/compiler/parse/src/number_literal.rs
index e9f3ed8a9c..1f6ee8609e 100644
--- a/compiler/parse/src/number_literal.rs
+++ b/compiler/parse/src/number_literal.rs
@@ -1,7 +1,5 @@
 use crate::ast::Base;
-use crate::parser::{parse_utf8, Number, ParseResult, Parser, Progress, State, SyntaxError};
-use std::char;
-use std::str::from_utf8_unchecked;
+use crate::parser::{Number, ParseResult, Parser, Progress, State};
 
 pub enum NumLiteral<'a> {
     Float(&'a str),
@@ -52,29 +50,21 @@ fn chomp_number_base<'a>(
 ) -> ParseResult<'a, NumLiteral<'a>, Number> {
     let (_is_float, chomped) = chomp_number(bytes);
 
-    match parse_utf8(&bytes[0..chomped]) {
-        Ok(string) => match state.advance_without_indenting(chomped + 2 + is_negative as usize) {
-            Ok(new) => {
-                // all is well
-                Ok((
-                    Progress::MadeProgress,
-                    NumLiteral::NonBase10Int {
-                        is_negative,
-                        string,
-                        base,
-                    },
-                    new,
-                ))
-            }
-            Err((_, SyntaxError::LineTooLong(_), new)) => {
-                // the only error we care about in this context
-                Err((Progress::MadeProgress, Number::LineTooLong, new))
-            }
-            Err(_) => unreachable!("we know advancing will succeed if there is space on the line"),
-        },
+    let string = unsafe { std::str::from_utf8_unchecked(&bytes[..chomped]) };
 
-        Err(_) => unreachable!("no invalid utf8 could have been chomped"),
-    }
+    let new = state.advance_without_indenting_ee(chomped + 2 + is_negative as usize, |_, _| {
+        Number::LineTooLong
+    })?;
+
+    Ok((
+        Progress::MadeProgress,
+        NumLiteral::NonBase10Int {
+            is_negative,
+            string,
+            base,
+        },
+        new,
+    ))
 }
 
 fn chomp_number_dec<'a>(
@@ -94,27 +84,21 @@ fn chomp_number_dec<'a>(
         return Err((Progress::NoProgress, Number::End, state));
     }
 
-    let string = unsafe { from_utf8_unchecked(&state.bytes[0..chomped + is_negative as usize]) };
+    let string =
+        unsafe { std::str::from_utf8_unchecked(&state.bytes[0..chomped + is_negative as usize]) };
 
-    match state.advance_without_indenting(chomped + is_negative as usize) {
-        Ok(new) => {
-            // all is well
-            Ok((
-                Progress::MadeProgress,
-                if is_float {
-                    NumLiteral::Float(string)
-                } else {
-                    NumLiteral::Num(string)
-                },
-                new,
-            ))
-        }
-        Err((_, SyntaxError::LineTooLong(_), new)) => {
-            // the only error we care about in this context
-            Err((Progress::MadeProgress, Number::LineTooLong, new))
-        }
-        Err(_) => unreachable!("we know advancing will succeed if there is space on the line"),
-    }
+    let new = state
+        .advance_without_indenting_ee(chomped + is_negative as usize, |_, _| Number::LineTooLong)?;
+
+    Ok((
+        Progress::MadeProgress,
+        if is_float {
+            NumLiteral::Float(string)
+        } else {
+            NumLiteral::Num(string)
+        },
+        new,
+    ))
 }
 
 fn chomp_number(mut bytes: &[u8]) -> (bool, usize) {
diff --git a/compiler/parse/src/parser.rs b/compiler/parse/src/parser.rs
index 96574653c9..96a1d6c16c 100644
--- a/compiler/parse/src/parser.rs
+++ b/compiler/parse/src/parser.rs
@@ -1,9 +1,7 @@
-use crate::ast::Attempting;
 use bumpalo::collections::vec::Vec;
 use bumpalo::Bump;
 use roc_region::all::{Located, Region};
 use std::fmt;
-use std::str::from_utf8;
 use Progress::*;
 
 /// A position in a source file.
@@ -59,13 +57,6 @@ impl<'a> State<'a> {
     /// This assumes we are *not* advancing with spaces, or at least that
     /// any spaces on the line were preceded by non-spaces - which would mean
     /// they weren't eligible to indent anyway.
-    pub fn advance_without_indenting(
-        self,
-        quantity: usize,
-    ) -> Result<Self, (Progress, SyntaxError<'a>, Self)> {
-        self.advance_without_indenting_ee(quantity, |line, _| SyntaxError::LineTooLong(line))
-    }
-
     pub fn advance_without_indenting_e<TE, E>(
         self,
         quantity: usize,
@@ -132,7 +123,7 @@ impl<'a> fmt::Debug for State<'a> {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         write!(f, "State {{")?;
 
-        match from_utf8(self.bytes) {
+        match std::str::from_utf8(self.bytes) {
             Ok(string) => write!(f, "\n\tbytes: [utf8] {:?}", string)?,
             Err(_) => write!(f, "\n\tbytes: [invalid utf8] {:?}", self.bytes)?,
         }
@@ -704,36 +695,6 @@ pub enum TVariable {
     Space(BadInputError, Row, Col),
 }
 
-#[derive(Debug, Clone, PartialEq, Eq)]
-pub enum ContextStack<'a> {
-    Cons(ContextItem, &'a ContextStack<'a>),
-    Nil,
-}
-
-impl<'a> ContextStack<'a> {
-    pub fn uncons(&'a self) -> Option<(ContextItem, &'a Self)> {
-        match self {
-            ContextStack::Cons(item, rest) => Some((*item, rest)),
-            ContextStack::Nil => None,
-        }
-    }
-}
-
-#[derive(Debug, Clone, Copy, PartialEq, Eq)]
-pub struct ContextItem {
-    pub line: u32,
-    pub column: u16,
-    pub context: Attempting,
-}
-
-#[derive(Debug, Clone, PartialEq, Eq)]
-pub struct DeadEnd<'a, T> {
-    pub line: u32,
-    pub column: u16,
-    pub problem: T,
-    pub context_stack: ContextStack<'a>,
-}
-
 /// use std vec to escape the arena's lifetime bound
 /// since this is only used when there is in fact an error
 /// I think this is fine
@@ -1862,23 +1823,6 @@ where
     map_with_arena!(parser, transform)
 }
 
-pub fn parse_utf8<'a>(bytes: &[u8]) -> Result<&str, SyntaxError<'a>> {
-    match from_utf8(bytes) {
-        Ok(string) => Ok(string),
-        Err(_) => Err(SyntaxError::BadUtf8),
-    }
-}
-
-pub fn end_of_file<'a>() -> impl Parser<'a, (), SyntaxError<'a>> {
-    |_arena: &'a Bump, state: State<'a>| {
-        if state.has_reached_end() {
-            Ok((NoProgress, (), state))
-        } else {
-            Err((NoProgress, SyntaxError::ConditionFailed, state))
-        }
-    }
-}
-
 pub fn backtrackable<'a, P, Val, Error>(parser: P) -> impl Parser<'a, Val, Error>
 where
     P: Parser<'a, Val, Error>,
diff --git a/compiler/parse/src/string_literal.rs b/compiler/parse/src/string_literal.rs
index f68cf849d1..4dd531ff33 100644
--- a/compiler/parse/src/string_literal.rs
+++ b/compiler/parse/src/string_literal.rs
@@ -1,9 +1,7 @@
 use crate::ast::{EscapedChar, StrLiteral, StrSegment};
 use crate::expr;
 use crate::parser::Progress::*;
-use crate::parser::{
-    allocated, loc, parse_utf8, specialize_ref, word1, BadInputError, EString, Parser, State,
-};
+use crate::parser::{allocated, loc, specialize_ref, word1, BadInputError, EString, Parser, State};
 use bumpalo::collections::vec::Vec;
 use bumpalo::Bump;
 
@@ -101,7 +99,7 @@ pub fn parse<'a>() -> impl Parser<'a, StrLiteral<'a>, EString<'a>> {
                     // to exclude that char we just parsed.
                     let string_bytes = &state.bytes[0..(segment_parsed_bytes - 1)];
 
-                    match parse_utf8(string_bytes) {
+                    match std::str::from_utf8(string_bytes) {
                         Ok(string) => {
                             state = advance_state!(state, string.len())?;
 

From c938a93dea5652fd0d70789933962d9288096df7 Mon Sep 17 00:00:00 2001
From: Folkert <folkert@folkertdev.nl>
Date: Fri, 12 Mar 2021 02:24:00 +0100
Subject: [PATCH 62/74] fix comment newline chomping issue

---
 compiler/parse/src/blankspace.rs | 16 ++++++++++++----
 1 file changed, 12 insertions(+), 4 deletions(-)

diff --git a/compiler/parse/src/blankspace.rs b/compiler/parse/src/blankspace.rs
index 7e05ef6d9d..d560fe969a 100644
--- a/compiler/parse/src/blankspace.rs
+++ b/compiler/parse/src/blankspace.rs
@@ -193,11 +193,18 @@ pub fn spaces_till_end_of_line<'a, E: 'a>(
                 b'#' => match chomp_line_comment(bytes) {
                     Ok(comment) => {
                         state.line += 1;
+                        state.column = 0;
 
-                        state.column += col + comment.len() as u16;
-                        state.bytes = &bytes[comment.len()..];
+                        let width = 1 + comment.len();
+                        if let Some(b'\n') = bytes.get(width) {
+                            state.bytes = &bytes[width + 1..];
+                        } else {
+                            state.bytes = &bytes[width..];
+                        }
                         state.is_indenting = true;
 
+                        dbg!(comment, &state);
+
                         return Ok((MadeProgress, Some(comment), state));
                     }
                     Err(_) => unreachable!("we check the first character is a #"),
@@ -214,6 +221,7 @@ pub fn spaces_till_end_of_line<'a, E: 'a>(
                 None,
                 State {
                     column: col,
+                    bytes,
                     ..state
                 },
             ))
@@ -275,8 +283,8 @@ where
                 debug_assert!(u16::MAX - state.indent_col >= spaces as u16);
                 debug_assert!(spaces <= u16::MAX as usize);
 
-                // state.indent_col + spaces as u16
-                state.indent_col
+                state.indent_col + spaces as u16
+                // state.indent_col
             } else {
                 state.indent_col
             };

From 222638e9bb41178f074f8dbb03887ac140adf405 Mon Sep 17 00:00:00 2001
From: Folkert <folkert@folkertdev.nl>
Date: Fri, 12 Mar 2021 02:28:57 +0100
Subject: [PATCH 63/74] confirm is_indenting is not needed

---
 compiler/parse/src/blankspace.rs | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/compiler/parse/src/blankspace.rs b/compiler/parse/src/blankspace.rs
index d560fe969a..43d7e90cf2 100644
--- a/compiler/parse/src/blankspace.rs
+++ b/compiler/parse/src/blankspace.rs
@@ -283,8 +283,8 @@ where
                 debug_assert!(u16::MAX - state.indent_col >= spaces as u16);
                 debug_assert!(spaces <= u16::MAX as usize);
 
-                state.indent_col + spaces as u16
-                // state.indent_col
+                // state.indent_col + spaces as u16
+                state.indent_col
             } else {
                 state.indent_col
             };

From f7744b4caa01051aaf7979ca0a71d6353e225f50 Mon Sep 17 00:00:00 2001
From: Folkert <folkert@folkertdev.nl>
Date: Fri, 12 Mar 2021 02:38:46 +0100
Subject: [PATCH 64/74] remove is_indenting

---
 compiler/parse/src/blankspace.rs | 44 ++++++--------------------------
 compiler/parse/src/parser.rs     |  9 +------
 2 files changed, 9 insertions(+), 44 deletions(-)

diff --git a/compiler/parse/src/blankspace.rs b/compiler/parse/src/blankspace.rs
index 43d7e90cf2..02c2bd2da8 100644
--- a/compiler/parse/src/blankspace.rs
+++ b/compiler/parse/src/blankspace.rs
@@ -172,7 +172,6 @@ pub fn spaces_till_end_of_line<'a, E: 'a>(
                     state.line = row;
                     state.column = col;
                     state.bytes = bytes;
-                    state.is_indenting = true;
 
                     return Ok((MadeProgress, None, state));
                 }
@@ -201,7 +200,6 @@ pub fn spaces_till_end_of_line<'a, E: 'a>(
                         } else {
                             state.bytes = &bytes[width..];
                         }
-                        state.is_indenting = true;
 
                         dbg!(comment, &state);
 
@@ -260,7 +258,7 @@ fn chomp_line_comment<'a>(buffer: &'a [u8]) -> Result<&'a str, Progress> {
 /// Advance the parser while also indenting as appropriate.
 /// This assumes we are only advancing with spaces, since they can indent.
 fn advance_spaces_e<'a, TE, E>(
-    state: &State<'a>,
+    state: State<'a>,
     spaces: usize,
     to_error: TE,
 ) -> Result<State<'a>, (Progress, E, State<'a>)>
@@ -268,37 +266,12 @@ where
     TE: Fn(Row, Col) -> E,
 {
     match (state.column as usize).checked_add(spaces) {
-        Some(column_usize) if column_usize <= u16::MAX as usize => {
-            // Spaces don't affect is_indenting; if we were previously indneting,
-            // we still are, and if we already finished indenting, we're still done.
-            let is_indenting = state.is_indenting;
-
-            // If we're indenting, spaces indent us further.
-            let indent_col = if is_indenting {
-                // This doesn't need to be checked_add because it's always true that
-                // indent_col <= col, so if this could possibly overflow, we would
-                // already have errored out from the column calculation.
-                //
-                // Leaving debug assertions in case this invariant someday disappers.
-                debug_assert!(u16::MAX - state.indent_col >= spaces as u16);
-                debug_assert!(spaces <= u16::MAX as usize);
-
-                // state.indent_col + spaces as u16
-                state.indent_col
-            } else {
-                state.indent_col
-            };
-
-            Ok(State {
-                bytes: &state.bytes[spaces..],
-                line: state.line,
-                column: column_usize as u16,
-                indent_col,
-                is_indenting,
-                original_len: state.original_len,
-            })
-        }
-        _ => Err(crate::parser::line_too_long_e(state.clone(), to_error)),
+        Some(column_usize) => Ok(State {
+            bytes: &state.bytes[spaces..],
+            column: column_usize as u16,
+            ..state
+        }),
+        _ => Err((NoProgress, to_error(state.line, state.column), state)),
     }
 }
 
@@ -319,7 +292,7 @@ pub fn spaces_exactly_e<'a>(spaces_expected: u16) -> impl Parser<'a, (), parser:
                     spaces_seen += 1;
                     if spaces_seen == spaces_expected {
                         let state =
-                            advance_spaces_e(&state, spaces_expected as usize, EExpr::IndentStart)?;
+                            advance_spaces_e(state, spaces_expected as usize, EExpr::IndentStart)?;
                         return Ok((MadeProgress, (), state));
                     }
                 }
@@ -379,7 +352,6 @@ where
                 } else if state.line != row {
                     // we parsed at least one newline
 
-                    state.is_indenting = true;
                     state.indent_col = col;
 
                     if col >= min_indent {
diff --git a/compiler/parse/src/parser.rs b/compiler/parse/src/parser.rs
index 96a1d6c16c..bd2589d7bb 100644
--- a/compiler/parse/src/parser.rs
+++ b/compiler/parse/src/parser.rs
@@ -5,7 +5,7 @@ use std::fmt;
 use Progress::*;
 
 /// A position in a source file.
-#[derive(Clone, PartialEq, Eq)]
+#[derive(Clone, Copy, PartialEq, Eq)]
 pub struct State<'a> {
     /// The raw input bytes from the file.
     pub bytes: &'a [u8],
@@ -19,10 +19,6 @@ pub struct State<'a> {
     /// (so no indent is col 1 - this saves an arithmetic operation.)
     pub indent_col: u16,
 
-    // true at the beginning of each line, then false after encountering
-    // the first nonspace char on that line.
-    pub is_indenting: bool,
-
     /// The original length of the string, before any bytes were consumed.
     /// This is used internally by the State::bytes_consumed() function.
     ///
@@ -43,7 +39,6 @@ impl<'a> State<'a> {
             line: 0,
             column: 0,
             indent_col: 0,
-            is_indenting: true,
             original_len: bytes.len(),
         }
     }
@@ -84,7 +79,6 @@ impl<'a> State<'a> {
                     bytes: &self.bytes[quantity..],
                     column: column_usize as u16,
                     // Once we hit a nonspace character, we are no longer indenting.
-                    is_indenting: false,
                     ..self
                 })
             }
@@ -130,7 +124,6 @@ impl<'a> fmt::Debug for State<'a> {
 
         write!(f, "\n\t(line, col): ({}, {}),", self.line, self.column)?;
         write!(f, "\n\tindent_col: {}", self.indent_col)?;
-        write!(f, "\n\tis_indenting: {:?}", self.is_indenting)?;
         write!(f, "\n\toriginal_len: {}", self.original_len)?;
         write!(f, "\n}}")
     }

From 362459b647123dbc728594875ac1afcf24a4d5a1 Mon Sep 17 00:00:00 2001
From: Folkert <folkert@folkertdev.nl>
Date: Fri, 12 Mar 2021 02:39:47 +0100
Subject: [PATCH 65/74] remove size from parser state

---
 compiler/parse/src/parser.rs | 8 --------
 1 file changed, 8 deletions(-)

diff --git a/compiler/parse/src/parser.rs b/compiler/parse/src/parser.rs
index bd2589d7bb..e4485e9906 100644
--- a/compiler/parse/src/parser.rs
+++ b/compiler/parse/src/parser.rs
@@ -18,12 +18,6 @@ pub struct State<'a> {
     /// Current indentation level, in columns
     /// (so no indent is col 1 - this saves an arithmetic operation.)
     pub indent_col: u16,
-
-    /// The original length of the string, before any bytes were consumed.
-    /// This is used internally by the State::bytes_consumed() function.
-    ///
-    /// TODO make this private, in a way that doesn't break macros!
-    pub original_len: usize,
 }
 
 #[derive(Debug, PartialEq, Eq)]
@@ -39,7 +33,6 @@ impl<'a> State<'a> {
             line: 0,
             column: 0,
             indent_col: 0,
-            original_len: bytes.len(),
         }
     }
 
@@ -124,7 +117,6 @@ impl<'a> fmt::Debug for State<'a> {
 
         write!(f, "\n\t(line, col): ({}, {}),", self.line, self.column)?;
         write!(f, "\n\tindent_col: {}", self.indent_col)?;
-        write!(f, "\n\toriginal_len: {}", self.original_len)?;
         write!(f, "\n}}")
     }
 }

From 4e4854ceaa1422bbbe4ebafee5ba192015af4f44 Mon Sep 17 00:00:00 2001
From: Folkert <folkert@folkertdev.nl>
Date: Fri, 12 Mar 2021 02:48:07 +0100
Subject: [PATCH 66/74] remove unneeded argument

---
 compiler/can/tests/helpers/mod.rs          |  2 +-
 compiler/fmt/tests/test_fmt.rs             |  4 ++--
 compiler/load/src/file.rs                  |  4 ++--
 compiler/parse/src/parser.rs               |  2 +-
 compiler/parse/src/test_helpers.rs         |  4 ++--
 compiler/parse/tests/test_parse.rs         | 24 +++++++++++-----------
 compiler/reporting/tests/helpers/mod.rs    |  2 +-
 compiler/reporting/tests/test_reporting.rs |  2 +-
 editor/src/lang/expr.rs                    |  2 +-
 editor/src/lang/roc_file.rs                |  2 +-
 10 files changed, 24 insertions(+), 24 deletions(-)

diff --git a/compiler/can/tests/helpers/mod.rs b/compiler/can/tests/helpers/mod.rs
index c7e51f219c..662ebd65b5 100644
--- a/compiler/can/tests/helpers/mod.rs
+++ b/compiler/can/tests/helpers/mod.rs
@@ -29,7 +29,7 @@ pub fn parse_loc_with<'a>(
     arena: &'a Bump,
     input: &'a str,
 ) -> Result<Located<ast::Expr<'a>>, SyntaxError<'a>> {
-    let state = State::new_in(arena, input.trim().as_bytes());
+    let state = State::new(input.trim().as_bytes());
 
     match roc_parse::expr::test_parse_expr(0, arena, state) {
         Ok((loc_expr, _state)) => Ok(loc_expr),
diff --git a/compiler/fmt/tests/test_fmt.rs b/compiler/fmt/tests/test_fmt.rs
index 13ade561a9..bda88c82f9 100644
--- a/compiler/fmt/tests/test_fmt.rs
+++ b/compiler/fmt/tests/test_fmt.rs
@@ -17,7 +17,7 @@ mod test_fmt {
     use roc_parse::parser::{Parser, State, SyntaxError};
 
     fn parse_with<'a>(arena: &'a Bump, input: &'a str) -> Result<Expr<'a>, SyntaxError<'a>> {
-        let state = State::new_in(arena, input.trim().as_bytes());
+        let state = State::new(input.trim().as_bytes());
 
         match roc_parse::expr::test_parse_expr(0, arena, state) {
             Ok((loc_expr, _state)) => Ok(loc_expr.value),
@@ -51,7 +51,7 @@ mod test_fmt {
         let src = src.trim_end();
         let expected = expected.trim_end();
 
-        match module::parse_header(&arena, State::new_in(&arena, src.as_bytes())) {
+        match module::parse_header(&arena, State::new(src.as_bytes())) {
             Ok((actual, state)) => {
                 let mut buf = String::new_in(&arena);
 
diff --git a/compiler/load/src/file.rs b/compiler/load/src/file.rs
index a92d075677..9082abf113 100644
--- a/compiler/load/src/file.rs
+++ b/compiler/load/src/file.rs
@@ -2304,7 +2304,7 @@ fn load_pkg_config<'a>(
         Ok(bytes_vec) => {
             let parse_start = SystemTime::now();
             let bytes = arena.alloc(bytes_vec);
-            let parse_state = parser::State::new_in(arena, bytes);
+            let parse_state = parser::State::new(bytes);
             let parsed = roc_parse::module::parse_header(&arena, parse_state);
             let parse_header_duration = parse_start.elapsed().unwrap();
 
@@ -2474,7 +2474,7 @@ fn parse_header<'a>(
     start_time: SystemTime,
 ) -> Result<(ModuleId, Msg<'a>), LoadingProblem<'a>> {
     let parse_start = SystemTime::now();
-    let parse_state = parser::State::new_in(arena, src_bytes);
+    let parse_state = parser::State::new(src_bytes);
     let parsed = roc_parse::module::parse_header(&arena, parse_state);
     let parse_header_duration = parse_start.elapsed().unwrap();
 
diff --git a/compiler/parse/src/parser.rs b/compiler/parse/src/parser.rs
index e4485e9906..001bfa299a 100644
--- a/compiler/parse/src/parser.rs
+++ b/compiler/parse/src/parser.rs
@@ -27,7 +27,7 @@ pub enum Either<First, Second> {
 }
 
 impl<'a> State<'a> {
-    pub fn new_in(arena: &'a Bump, bytes: &'a [u8]) -> State<'a> {
+    pub fn new(bytes: &'a [u8]) -> State<'a> {
         State {
             bytes,
             line: 0,
diff --git a/compiler/parse/src/test_helpers.rs b/compiler/parse/src/test_helpers.rs
index 4d9f83efaa..e70782358f 100644
--- a/compiler/parse/src/test_helpers.rs
+++ b/compiler/parse/src/test_helpers.rs
@@ -17,7 +17,7 @@ pub fn parse_defs_with<'a>(
     arena: &'a Bump,
     input: &'a str,
 ) -> Result<Vec<'a, Located<ast::Def<'a>>>, SyntaxError<'a>> {
-    let state = State::new_in(arena, input.trim().as_bytes());
+    let state = State::new(input.trim().as_bytes());
     let answer = module_defs().parse(arena, state);
     answer
         .map(|(_, loc_expr, _)| loc_expr)
@@ -29,7 +29,7 @@ pub fn parse_loc_with<'a>(
     arena: &'a Bump,
     input: &'a str,
 ) -> Result<Located<ast::Expr<'a>>, SyntaxError<'a>> {
-    let state = State::new_in(arena, input.trim().as_bytes());
+    let state = State::new(input.trim().as_bytes());
 
     match crate::expr::test_parse_expr(0, arena, state) {
         Ok((loc_expr, _state)) => Ok(loc_expr),
diff --git a/compiler/parse/tests/test_parse.rs b/compiler/parse/tests/test_parse.rs
index b149b1b00f..a152464ce0 100644
--- a/compiler/parse/tests/test_parse.rs
+++ b/compiler/parse/tests/test_parse.rs
@@ -2433,7 +2433,7 @@ mod test_parse {
                 app "test-app" packages {} imports [] provides [] to blah
             "#
         );
-        let actual = roc_parse::module::parse_header(&arena, State::new_in(&arena, src.as_bytes()))
+        let actual = roc_parse::module::parse_header(&arena, State::new(src.as_bytes()))
             .map(|tuple| tuple.0);
 
         assert_eq!(Ok(expected), actual);
@@ -2473,7 +2473,7 @@ mod test_parse {
             "#
         );
 
-        let actual = roc_parse::module::parse_header(&arena, State::new_in(&arena, src.as_bytes()))
+        let actual = roc_parse::module::parse_header(&arena, State::new(src.as_bytes()))
             .map(|tuple| tuple.0);
 
         assert_eq!(Ok(expected), actual);
@@ -2528,7 +2528,7 @@ mod test_parse {
             "#
         );
 
-        let actual = roc_parse::module::parse_header(&arena, State::new_in(&arena, src.as_bytes()))
+        let actual = roc_parse::module::parse_header(&arena, State::new(src.as_bytes()))
             .map(|tuple| tuple.0);
 
         assert_eq!(Ok(expected), actual);
@@ -2573,7 +2573,7 @@ mod test_parse {
         let expected = roc_parse::ast::Module::Platform { header };
 
         let src = "platform rtfeldman/blah requires {} exposes [] packages {} imports [] provides [] effects fx.Blah {}";
-        let actual = roc_parse::module::parse_header(&arena, State::new_in(&arena, src.as_bytes()))
+        let actual = roc_parse::module::parse_header(&arena, State::new(src.as_bytes()))
             .map(|tuple| tuple.0);
 
         assert_eq!(Ok(expected), actual);
@@ -2642,7 +2642,7 @@ mod test_parse {
                     effects fx.Effect {}
             "#
         );
-        let actual = roc_parse::module::parse_header(&arena, State::new_in(&arena, src.as_bytes()))
+        let actual = roc_parse::module::parse_header(&arena, State::new(src.as_bytes()))
             .map(|tuple| tuple.0);
 
         assert_eq!(Ok(expected), actual);
@@ -2673,7 +2673,7 @@ mod test_parse {
                 interface Foo exposes [] imports []
             "#
         );
-        let actual = roc_parse::module::parse_header(&arena, State::new_in(&arena, src.as_bytes()))
+        let actual = roc_parse::module::parse_header(&arena, State::new(src.as_bytes()))
             .map(|tuple| tuple.0);
 
         assert_eq!(Ok(expected), actual);
@@ -2704,7 +2704,7 @@ mod test_parse {
                 interface Foo.Bar.Baz exposes [] imports []
             "#
         );
-        let actual = roc_parse::module::parse_header(&arena, State::new_in(&arena, src.as_bytes()))
+        let actual = roc_parse::module::parse_header(&arena, State::new(src.as_bytes()))
             .map(|tuple| tuple.0);
 
         assert_eq!(Ok(expected), actual);
@@ -2731,7 +2731,7 @@ mod test_parse {
             "#
         );
         let actual = module_defs()
-            .parse(&arena, State::new_in(&arena, src.as_bytes()))
+            .parse(&arena, State::new(src.as_bytes()))
             .map(|tuple| tuple.1);
 
         // It should occur twice in the debug output - once for the pattern,
@@ -2790,7 +2790,7 @@ mod test_parse {
         );
 
         let actual = module_defs()
-            .parse(&arena, State::new_in(&arena, src.as_bytes()))
+            .parse(&arena, State::new(src.as_bytes()))
             .map(|tuple| tuple.1);
 
         assert_eq!(Ok(expected), actual);
@@ -2810,7 +2810,7 @@ mod test_parse {
         );
 
         let actual = module_defs()
-            .parse(&arena, State::new_in(&arena, src.as_bytes()))
+            .parse(&arena, State::new(src.as_bytes()))
             .map(|tuple| tuple.0);
 
         assert!(actual.is_ok());
@@ -2832,7 +2832,7 @@ mod test_parse {
         );
 
         let actual = module_defs()
-            .parse(&arena, State::new_in(&arena, src.as_bytes()))
+            .parse(&arena, State::new(src.as_bytes()))
             .map(|tuple| tuple.0);
 
         assert!(actual.is_ok());
@@ -2852,7 +2852,7 @@ mod test_parse {
             "#
         );
 
-        let state = State::new_in(arena, src.as_bytes());
+        let state = State::new(src.as_bytes());
         let parser = module_defs();
         let parsed = parser.parse(arena, state);
         match parsed {
diff --git a/compiler/reporting/tests/helpers/mod.rs b/compiler/reporting/tests/helpers/mod.rs
index a242ba2076..f5f8d128cb 100644
--- a/compiler/reporting/tests/helpers/mod.rs
+++ b/compiler/reporting/tests/helpers/mod.rs
@@ -109,7 +109,7 @@ pub fn parse_loc_with<'a>(
     arena: &'a Bump,
     input: &'a str,
 ) -> Result<Located<ast::Expr<'a>>, SyntaxError<'a>> {
-    let state = State::new_in(arena, input.trim().as_bytes());
+    let state = State::new(input.trim().as_bytes());
 
     match roc_parse::expr::test_parse_expr(0, arena, state) {
         Ok((loc_expr, _state)) => Ok(loc_expr),
diff --git a/compiler/reporting/tests/test_reporting.rs b/compiler/reporting/tests/test_reporting.rs
index 46c5c00a0a..2a0f18dd5e 100644
--- a/compiler/reporting/tests/test_reporting.rs
+++ b/compiler/reporting/tests/test_reporting.rs
@@ -177,7 +177,7 @@ mod test_reporting {
 
         use roc_parse::parser::State;
 
-        let state = State::new_in(arena, src.as_bytes());
+        let state = State::new(src.as_bytes());
 
         let filename = filename_from_string(r"\code\proj\Main.roc");
         let src_lines: Vec<&str> = src.split('\n').collect();
diff --git a/editor/src/lang/expr.rs b/editor/src/lang/expr.rs
index 58243df0ce..1ec15169ed 100644
--- a/editor/src/lang/expr.rs
+++ b/editor/src/lang/expr.rs
@@ -234,7 +234,7 @@ pub fn str_to_expr2<'a>(
     scope: &mut Scope,
     region: Region,
 ) -> Result<(Expr2, self::Output), SyntaxError<'a>> {
-    let state = State::new_in(arena, input.trim().as_bytes());
+    let state = State::new(input.trim().as_bytes());
 
     match roc_parse::expr::test_parse_expr(0, arena, state) {
         Ok((loc_expr, _state)) => Ok(to_expr2(env, scope, arena.alloc(loc_expr.value), region)),
diff --git a/editor/src/lang/roc_file.rs b/editor/src/lang/roc_file.rs
index f551d987e2..98f1a25210 100644
--- a/editor/src/lang/roc_file.rs
+++ b/editor/src/lang/roc_file.rs
@@ -36,7 +36,7 @@ impl<'a> File<'a> {
 
         let allocation = arena.alloc(bytes);
 
-        let module_parse_state = parser::State::new_in(arena, allocation);
+        let module_parse_state = parser::State::new(allocation);
         let parsed_module = roc_parse::module::parse_header(&arena, module_parse_state);
 
         match parsed_module {

From 9f146bf702a43a0e9e230bd27a52199a42737b7e Mon Sep 17 00:00:00 2001
From: Folkert <folkert@folkertdev.nl>
Date: Fri, 12 Mar 2021 02:52:36 +0100
Subject: [PATCH 67/74] remove syntax error

---
 compiler/parse/src/expr.rs            | 2 +-
 compiler/parse/src/parser.rs          | 3 ---
 compiler/reporting/src/error/parse.rs | 2 --
 3 files changed, 1 insertion(+), 6 deletions(-)

diff --git a/compiler/parse/src/expr.rs b/compiler/parse/src/expr.rs
index 7bf9b8393d..01f7f09b70 100644
--- a/compiler/parse/src/expr.rs
+++ b/compiler/parse/src/expr.rs
@@ -1193,7 +1193,7 @@ fn parse_def_signature_help<'a>(
         and!(
             // Optionally parse additional defs.
             zero_or_more!(backtrackable(allocated(space0_before_e(
-                loc!(specialize_ref(EExpr::Syntax, def(original_indent))),
+                loc!(def_help(original_indent)),
                 original_indent,
                 EExpr::Space,
                 EExpr::IndentStart,
diff --git a/compiler/parse/src/parser.rs b/compiler/parse/src/parser.rs
index 001bfa299a..ded7e62c4c 100644
--- a/compiler/parse/src/parser.rs
+++ b/compiler/parse/src/parser.rs
@@ -378,7 +378,6 @@ pub enum EExpr<'a> {
     UnaryNegate(Row, Col),
     BadOperator(&'a [u8], Row, Col),
 
-    Def(&'a SyntaxError<'a>, Row, Col),
     DefMissingFinalExpr(Row, Col),
     Type(Type<'a>, Row, Col),
     Pattern(&'a EPattern<'a>, Row, Col),
@@ -395,8 +394,6 @@ pub enum EExpr<'a> {
     BackpassComma(Row, Col),
     BackpassArrow(Row, Col),
 
-    Syntax(&'a SyntaxError<'a>, Row, Col),
-
     When(When<'a>, Row, Col),
     If(If<'a>, Row, Col),
 
diff --git a/compiler/reporting/src/error/parse.rs b/compiler/reporting/src/error/parse.rs
index 42402bad9d..8c8c89ffc3 100644
--- a/compiler/reporting/src/error/parse.rs
+++ b/compiler/reporting/src/error/parse.rs
@@ -198,8 +198,6 @@ fn to_expr_report<'a>(
             to_expr_in_parens_report(alloc, filename, context, &expr, *row, *col)
         }
         EExpr::Type(tipe, row, col) => to_type_report(alloc, filename, &tipe, *row, *col),
-        EExpr::Def(syntax, row, col) => to_syntax_report(alloc, filename, syntax, *row, *col),
-
         EExpr::ElmStyleFunction(region, row, col) => {
             let surroundings = Region::from_rows_cols(start_row, start_col, *row, *col);
             let region = *region;

From b688fd11a99c4f1f6f825d5d902886d1b0750cd2 Mon Sep 17 00:00:00 2001
From: Folkert <folkert@folkertdev.nl>
Date: Fri, 12 Mar 2021 02:54:25 +0100
Subject: [PATCH 68/74] remove syntax error

---
 compiler/parse/src/expr.rs   | 6 +++++-
 compiler/parse/src/parser.rs | 2 +-
 2 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/compiler/parse/src/expr.rs b/compiler/parse/src/expr.rs
index 01f7f09b70..909eaffbef 100644
--- a/compiler/parse/src/expr.rs
+++ b/compiler/parse/src/expr.rs
@@ -48,6 +48,10 @@ pub fn expr<'a>(min_indent: u16) -> impl Parser<'a, Expr<'a>, SyntaxError<'a>> {
     )
 }
 
+fn expr_help<'a>(min_indent: u16) -> impl Parser<'a, Expr<'a>, EExpr<'a>> {
+    move |arena, state: State<'a>| parse_expr_help(min_indent, arena, state)
+}
+
 fn loc_expr_in_parens_help<'a>(
     min_indent: u16,
 ) -> impl Parser<'a, Located<Expr<'a>>, EInParens<'a>> {
@@ -2106,7 +2110,7 @@ fn record_field_help<'a>(
                 word1(b'?', ERecord::QuestionMark)
             ),
             space0_before_e(
-                specialize_ref(ERecord::Syntax, loc!(expr(min_indent))),
+                specialize_ref(ERecord::Expr, loc!(expr_help(min_indent))),
                 min_indent,
                 ERecord::Space,
                 ERecord::IndentEnd,
diff --git a/compiler/parse/src/parser.rs b/compiler/parse/src/parser.rs
index ded7e62c4c..b64acc62a7 100644
--- a/compiler/parse/src/parser.rs
+++ b/compiler/parse/src/parser.rs
@@ -443,7 +443,7 @@ pub enum ERecord<'a> {
     Ampersand(Row, Col),
 
     // TODO remove
-    Syntax(&'a SyntaxError<'a>, Row, Col),
+    Expr(&'a EExpr<'a>, Row, Col),
 
     Space(BadInputError, Row, Col),
 

From e815e57dcfa90798f74f4f30b26f4f60b6055a93 Mon Sep 17 00:00:00 2001
From: Folkert <folkert@folkertdev.nl>
Date: Fri, 12 Mar 2021 03:04:47 +0100
Subject: [PATCH 69/74] remove more syntax errors

---
 compiler/parse/src/expr.rs            |  4 ++--
 compiler/parse/src/parser.rs          | 15 ++++--------
 compiler/parse/src/pattern.rs         | 13 +++--------
 compiler/parse/src/string_literal.rs  |  2 +-
 compiler/reporting/src/error/parse.rs | 33 ++++++++++++++++++++++-----
 5 files changed, 37 insertions(+), 30 deletions(-)

diff --git a/compiler/parse/src/expr.rs b/compiler/parse/src/expr.rs
index 909eaffbef..5aa810b7b8 100644
--- a/compiler/parse/src/expr.rs
+++ b/compiler/parse/src/expr.rs
@@ -48,7 +48,7 @@ pub fn expr<'a>(min_indent: u16) -> impl Parser<'a, Expr<'a>, SyntaxError<'a>> {
     )
 }
 
-fn expr_help<'a>(min_indent: u16) -> impl Parser<'a, Expr<'a>, EExpr<'a>> {
+pub fn expr_help<'a>(min_indent: u16) -> impl Parser<'a, Expr<'a>, EExpr<'a>> {
     move |arena, state: State<'a>| parse_expr_help(min_indent, arena, state)
 }
 
@@ -2062,7 +2062,7 @@ fn list_literal_help<'a>(min_indent: u16) -> impl Parser<'a, Expr<'a>, List<'a>>
     move |arena, state| {
         let (_, (parsed_elems, final_comments), state) = collection_trailing_sep_e!(
             word1(b'[', List::Open),
-            specialize_ref(List::Syntax, loc!(expr(min_indent))),
+            specialize_ref(List::Expr, loc!(expr_help(min_indent))),
             word1(b',', List::End),
             word1(b']', List::End),
             min_indent,
diff --git a/compiler/parse/src/parser.rs b/compiler/parse/src/parser.rs
index b64acc62a7..f6d98d1145 100644
--- a/compiler/parse/src/parser.rs
+++ b/compiler/parse/src/parser.rs
@@ -426,7 +426,7 @@ pub enum EString<'a> {
     EndlessSingle(Row, Col),
     EndlessMulti(Row, Col),
     UnknownEscape(Row, Col),
-    Format(&'a SyntaxError<'a>, Row, Col),
+    Format(&'a EExpr<'a>, Row, Col),
     FormatEnd(Row, Col),
 }
 
@@ -489,7 +489,6 @@ pub enum List<'a> {
     End(Row, Col),
     Space(BadInputError, Row, Col),
 
-    Syntax(&'a SyntaxError<'a>, Row, Col),
     Expr(&'a EExpr<'a>, Row, Col),
 
     IndentOpen(Row, Col),
@@ -510,7 +509,6 @@ pub enum When<'a> {
 
     Condition(&'a EExpr<'a>, Row, Col),
     Branch(&'a EExpr<'a>, Row, Col),
-    Syntax(&'a SyntaxError<'a>, Row, Col),
 
     IndentIs(Row, Col),
     IndentCondition(Row, Col),
@@ -531,7 +529,6 @@ pub enum If<'a> {
     Condition(&'a EExpr<'a>, Row, Col),
     ThenBranch(&'a EExpr<'a>, Row, Col),
     ElseBranch(&'a EExpr<'a>, Row, Col),
-    Syntax(&'a SyntaxError<'a>, Row, Col),
 
     IndentCondition(Row, Col),
     IndentIf(Row, Col),
@@ -566,9 +563,9 @@ pub enum PRecord<'a> {
     Field(Row, Col),
     Colon(Row, Col),
     Optional(Row, Col),
+
     Pattern(&'a EPattern<'a>, Row, Col),
-    // TODO remove
-    Syntax(&'a SyntaxError<'a>, Row, Col),
+    Expr(&'a EExpr<'a>, Row, Col),
 
     Space(BadInputError, Row, Col),
 
@@ -582,13 +579,9 @@ pub enum PRecord<'a> {
 pub enum PInParens<'a> {
     End(Row, Col),
     Open(Row, Col),
-    ///
-    // TODO remove
-    Syntax(&'a SyntaxError<'a>, Row, Col),
+    Pattern(&'a EPattern<'a>, Row, Col),
 
-    ///
     Space(BadInputError, Row, Col),
-    ///
     IndentOpen(Row, Col),
     IndentEnd(Row, Col),
 }
diff --git a/compiler/parse/src/pattern.rs b/compiler/parse/src/pattern.rs
index 146940d790..781fc4afc3 100644
--- a/compiler/parse/src/pattern.rs
+++ b/compiler/parse/src/pattern.rs
@@ -51,13 +51,6 @@ fn parse_closure_param<'a>(
     .parse(arena, state)
 }
 
-pub fn loc_pattern<'a>(min_indent: u16) -> impl Parser<'a, Located<Pattern<'a>>, SyntaxError<'a>> {
-    specialize(
-        |e, _, _| SyntaxError::Pattern(e),
-        loc_pattern_help(min_indent),
-    )
-}
-
 pub fn loc_pattern_help<'a>(
     min_indent: u16,
 ) -> impl Parser<'a, Located<Pattern<'a>>, EPattern<'a>> {
@@ -130,7 +123,7 @@ fn loc_pattern_in_parens_help<'a>(
     between!(
         word1(b'(', PInParens::Open),
         space0_around_ee(
-            move |arena, state| specialize_ref(PInParens::Syntax, loc_pattern(min_indent))
+            move |arena, state| specialize_ref(PInParens::Pattern, loc_pattern_help(min_indent))
                 .parse(arena, state),
             min_indent,
             PInParens::Space,
@@ -386,7 +379,7 @@ fn record_pattern_field<'a>(min_indent: u16) -> impl Parser<'a, Located<Pattern<
 
         match opt_loc_val {
             Some(First(_)) => {
-                let val_parser = specialize_ref(PRecord::Syntax, loc_pattern(min_indent));
+                let val_parser = specialize_ref(PRecord::Pattern, loc_pattern_help(min_indent));
                 let (_, loc_val, state) =
                     space0_before_e(val_parser, min_indent, PRecord::Space, PRecord::IndentColon)
                         .parse(arena, state)?;
@@ -414,7 +407,7 @@ fn record_pattern_field<'a>(min_indent: u16) -> impl Parser<'a, Located<Pattern<
             }
             Some(Second(_)) => {
                 let val_parser =
-                    specialize_ref(PRecord::Syntax, loc!(crate::expr::expr(min_indent)));
+                    specialize_ref(PRecord::Expr, loc!(crate::expr::expr_help(min_indent)));
 
                 let (_, loc_val, state) =
                     space0_before_e(val_parser, min_indent, PRecord::Space, PRecord::IndentColon)
diff --git a/compiler/parse/src/string_literal.rs b/compiler/parse/src/string_literal.rs
index 4dd531ff33..740ef52f29 100644
--- a/compiler/parse/src/string_literal.rs
+++ b/compiler/parse/src/string_literal.rs
@@ -231,7 +231,7 @@ pub fn parse<'a>() -> impl Parser<'a, StrLiteral<'a>, EString<'a>> {
                             // canonicalization error if that expression variant
                             // is not allowed inside a string interpolation.
                             let (_progress, loc_expr, new_state) = skip_second!(
-                                specialize_ref(EString::Format, loc(allocated(expr::expr(0)))),
+                                specialize_ref(EString::Format, loc(allocated(expr::expr_help(0)))),
                                 word1(b')', EString::FormatEnd)
                             )
                             .parse(arena, state)?;
diff --git a/compiler/reporting/src/error/parse.rs b/compiler/reporting/src/error/parse.rs
index 8c8c89ffc3..f0bdeafe68 100644
--- a/compiler/reporting/src/error/parse.rs
+++ b/compiler/reporting/src/error/parse.rs
@@ -172,6 +172,8 @@ enum Node {
     IfElseBranch,
     ListElement,
     InsideParens,
+    RecordConditionalDefault,
+    StringFormat,
 }
 
 fn to_expr_report<'a>(
@@ -343,6 +345,8 @@ fn to_expr_report<'a>(
                         ]),
                     ),
                     Node::ListElement => (r, c, alloc.text("a list")),
+                    Node::RecordConditionalDefault => (r, c, alloc.text("record field default")),
+                    Node::StringFormat => (r, c, alloc.text("a string format")),
                     Node::InsideParens => (r, c, alloc.text("some parentheses")),
                 },
                 Context::InDef(r, c) => (r, c, alloc.text("a definition")),
@@ -662,7 +666,7 @@ fn to_unfinished_lambda_report<'a>(
 fn to_str_report<'a>(
     alloc: &'a RocDocAllocator<'a>,
     filename: PathBuf,
-    _context: Context,
+    context: Context,
     parse_problem: &roc_parse::parser::EString<'a>,
     start_row: Row,
     start_col: Col,
@@ -671,7 +675,14 @@ fn to_str_report<'a>(
 
     match *parse_problem {
         EString::Open(_row, _col) => unreachable!("another branch would be taken"),
-        EString::Format(syntax, row, col) => to_syntax_report(alloc, filename, syntax, row, col),
+        EString::Format(expr, row, col) => to_expr_report(
+            alloc,
+            filename,
+            Context::InNode(Node::StringFormat, start_row, start_col, Box::new(context)),
+            expr,
+            row,
+            col,
+        ),
         EString::Space(error, row, col) => to_space_report(alloc, filename, &error, row, col),
         EString::UnknownEscape(row, col) => {
             let surroundings = Region::from_rows_cols(start_row, start_col, row, col);
@@ -885,7 +896,6 @@ fn to_list_report<'a>(
     use roc_parse::parser::List;
 
     match *parse_problem {
-        List::Syntax(syntax, row, col) => to_syntax_report(alloc, filename, syntax, row, col),
         List::Space(error, row, col) => to_space_report(alloc, filename, &error, row, col),
 
         List::Expr(expr, row, col) => to_expr_report(
@@ -994,7 +1004,6 @@ fn to_if_report<'a>(
     use roc_parse::parser::If;
 
     match *parse_problem {
-        If::Syntax(syntax, row, col) => to_syntax_report(alloc, filename, syntax, row, col),
         If::Space(error, row, col) => to_space_report(alloc, filename, &error, row, col),
 
         If::Condition(expr, row, col) => to_expr_report(
@@ -1165,7 +1174,6 @@ fn to_when_report<'a>(
             }
         }
 
-        When::Syntax(syntax, row, col) => to_syntax_report(alloc, filename, syntax, row, col),
         When::Space(error, row, col) => to_space_report(alloc, filename, &error, row, col),
 
         When::Branch(expr, row, col) => to_expr_report(
@@ -1558,7 +1566,20 @@ fn to_precord_report<'a>(
         PRecord::Pattern(pattern, row, col) => {
             to_pattern_report(alloc, filename, pattern, row, col)
         }
-        PRecord::Syntax(syntax, row, col) => to_syntax_report(alloc, filename, syntax, row, col),
+
+        PRecord::Expr(expr, row, col) => to_expr_report(
+            alloc,
+            filename,
+            Context::InNode(
+                Node::RecordConditionalDefault,
+                start_row,
+                start_col,
+                Box::new(Context::InDef(row, col)),
+            ),
+            expr,
+            row,
+            col,
+        ),
 
         PRecord::IndentOpen(row, col) => {
             let surroundings = Region::from_rows_cols(start_row, start_col, row, col);

From 16a2dfd05844e166930f06a729f96eb14f79fa9e Mon Sep 17 00:00:00 2001
From: Folkert <folkert@folkertdev.nl>
Date: Fri, 12 Mar 2021 03:10:57 +0100
Subject: [PATCH 70/74] remove unused functions

---
 compiler/parse/src/parser.rs | 92 +-----------------------------------
 1 file changed, 1 insertion(+), 91 deletions(-)

diff --git a/compiler/parse/src/parser.rs b/compiler/parse/src/parser.rs
index f6d98d1145..16921afd31 100644
--- a/compiler/parse/src/parser.rs
+++ b/compiler/parse/src/parser.rs
@@ -75,7 +75,7 @@ impl<'a> State<'a> {
                     ..self
                 })
             }
-            _ => Err(line_too_long_e(self.clone(), to_error)),
+            _ => Err((NoProgress, to_error(self.line, self.column), self)),
         }
     }
 
@@ -670,9 +670,6 @@ pub enum TVariable {
     Space(BadInputError, Row, Col),
 }
 
-/// use std vec to escape the arena's lifetime bound
-/// since this is only used when there is in fact an error
-/// I think this is fine
 #[derive(Debug)]
 pub struct ParseProblem<'a, T> {
     pub line: u32,
@@ -682,10 +679,6 @@ pub struct ParseProblem<'a, T> {
     pub bytes: &'a [u8],
 }
 
-pub fn fail<'a, T>() -> impl Parser<'a, T, SyntaxError<'a>> {
-    move |_arena, state: State<'a>| Err((NoProgress, SyntaxError::ConditionFailed, state))
-}
-
 pub trait Parser<'a, Output, Error> {
     fn parse(&self, _: &'a Bump, _: State<'a>) -> ParseResult<'a, Output, Error>;
 }
@@ -713,46 +706,6 @@ where
     }
 }
 
-pub fn not_followed_by<'a, P, ByParser, By, Val>(
-    parser: P,
-    by: ByParser,
-) -> impl Parser<'a, Val, SyntaxError<'a>>
-where
-    ByParser: Parser<'a, By, SyntaxError<'a>>,
-    P: Parser<'a, Val, SyntaxError<'a>>,
-{
-    move |arena, state: State<'a>| {
-        let original_state = state.clone();
-
-        parser
-            .parse(arena, state)
-            .and_then(|(progress, answer, state)| {
-                let after_parse = state.clone();
-
-                match by.parse(arena, state) {
-                    Ok((_, _, _state)) => {
-                        Err((NoProgress, SyntaxError::ConditionFailed, original_state))
-                    }
-                    Err(_) => Ok((progress, answer, after_parse)),
-                }
-            })
-    }
-}
-
-pub fn not<'a, P, Val>(parser: P) -> impl Parser<'a, (), SyntaxError<'a>>
-where
-    P: Parser<'a, Val, SyntaxError<'a>>,
-{
-    move |arena, state: State<'a>| {
-        let original_state = state.clone();
-
-        match parser.parse(arena, state) {
-            Ok((_, _, _)) => Err((NoProgress, SyntaxError::ConditionFailed, original_state)),
-            Err((_, _, _)) => Ok((NoProgress, (), original_state)),
-        }
-    }
-}
-
 pub fn not_e<'a, P, TE, E, X, Val>(parser: P, to_error: TE) -> impl Parser<'a, (), E>
 where
     TE: Fn(Row, Col) -> E,
@@ -773,23 +726,6 @@ where
     }
 }
 
-pub fn lookahead<'a, Peek, P, PeekVal, Val, Error>(
-    peek: Peek,
-    parser: P,
-) -> impl Parser<'a, Val, Error>
-where
-    Error: 'a,
-    Peek: Parser<'a, PeekVal, Error>,
-    P: Parser<'a, Val, Error>,
-{
-    move |arena, state: State<'a>| {
-        let original_state = state.clone();
-
-        peek.parse(arena, state)
-            .and_then(|_| parser.parse(arena, original_state))
-    }
-}
-
 pub fn and_then<'a, P1, P2, F, Before, After, Error>(
     parser: P1,
     transform: F,
@@ -844,32 +780,6 @@ where
     }
 }
 
-// TODO remove
-pub fn line_too_long_e<TE, E>(state: State, to_error: TE) -> (Progress, E, State)
-where
-    TE: Fn(Row, Col) -> E,
-{
-    let problem = to_error(state.line, state.column);
-    // Set column to MAX and advance the parser to end of input.
-    // This way, all future parsers will fail on EOF, and then
-    // unexpected_eof will take them back here - thus propagating
-    // the initial LineTooLong error all the way to the end, even if
-    // (for example) the LineTooLong initially occurs in the middle of
-    // a one_of chain, which would otherwise prevent it from propagating.
-    let column = u16::MAX;
-    let bytes = state.bytes.get(0..state.bytes.len()).unwrap();
-    let state = State {
-        bytes,
-        line: state.line,
-        column,
-        ..state
-    };
-
-    // TODO do we make progress in this case?
-    // isn't this error fatal?
-    (Progress::NoProgress, problem, state)
-}
-
 pub fn keyword_e<'a, ToError, E>(keyword: &'static str, if_error: ToError) -> impl Parser<'a, (), E>
 where
     ToError: Fn(Row, Col) -> E,

From b349ae7ab556641c276d531ae56e935167c3b964 Mon Sep 17 00:00:00 2001
From: Folkert <folkert@folkertdev.nl>
Date: Fri, 12 Mar 2021 03:18:31 +0100
Subject: [PATCH 71/74] type variable errors

---
 compiler/parse/src/ident.rs           |  2 +-
 compiler/parse/src/parser.rs          | 30 +----------------------
 compiler/parse/src/type_annotation.rs | 34 ++++++++++-----------------
 compiler/reporting/src/error/parse.rs |  1 -
 4 files changed, 15 insertions(+), 52 deletions(-)

diff --git a/compiler/parse/src/ident.rs b/compiler/parse/src/ident.rs
index 9a239456e9..a22c2348e2 100644
--- a/compiler/parse/src/ident.rs
+++ b/compiler/parse/src/ident.rs
@@ -63,7 +63,7 @@ pub fn lowercase_ident<'a>() -> impl Parser<'a, &'a str, ()> {
         Err(progress) => Err((progress, (), state)),
         Ok(ident) => {
             if crate::keyword::KEYWORDS.iter().any(|kw| &ident == kw) {
-                Err((MadeProgress, (), state))
+                Err((NoProgress, (), state))
             } else {
                 let width = ident.len();
                 match state.advance_without_indenting_ee(width, |_, _| ()) {
diff --git a/compiler/parse/src/parser.rs b/compiler/parse/src/parser.rs
index 16921afd31..793c6bfdb5 100644
--- a/compiler/parse/src/parser.rs
+++ b/compiler/parse/src/parser.rs
@@ -592,7 +592,7 @@ pub enum Type<'a> {
     TTagUnion(TTagUnion<'a>, Row, Col),
     TInParens(TInParens<'a>, Row, Col),
     TApply(TApply, Row, Col),
-    TVariable(TVariable, Row, Col),
+    TBadTypeVariable(Row, Col),
     TWildcard(Row, Col),
     ///
     TStart(Row, Col),
@@ -662,14 +662,6 @@ pub enum TApply {
     StartIsNumber(Row, Col),
 }
 
-#[derive(Debug, Clone, PartialEq, Eq)]
-pub enum TVariable {
-    ///
-    StartNotLowercase(Row, Col),
-    End(Row, Col),
-    Space(BadInputError, Row, Col),
-}
-
 #[derive(Debug)]
 pub struct ParseProblem<'a, T> {
     pub line: u32,
@@ -706,26 +698,6 @@ where
     }
 }
 
-pub fn not_e<'a, P, TE, E, X, Val>(parser: P, to_error: TE) -> impl Parser<'a, (), E>
-where
-    TE: Fn(Row, Col) -> E,
-    P: Parser<'a, Val, X>,
-    E: 'a,
-{
-    move |arena, state: State<'a>| {
-        let original_state = state.clone();
-
-        match parser.parse(arena, state) {
-            Ok((_, _, _)) => Err((
-                NoProgress,
-                to_error(original_state.line, original_state.column),
-                original_state,
-            )),
-            Err((_, _, _)) => Ok((NoProgress, (), original_state)),
-        }
-    }
-}
-
 pub fn and_then<'a, P1, P2, F, Before, After, Error>(
     parser: P1,
     transform: F,
diff --git a/compiler/parse/src/type_annotation.rs b/compiler/parse/src/type_annotation.rs
index cb81688734..9cc07f713a 100644
--- a/compiler/parse/src/type_annotation.rs
+++ b/compiler/parse/src/type_annotation.rs
@@ -2,10 +2,10 @@ use crate::ast::{AssignedField, Tag, TypeAnnotation};
 use crate::blankspace::{space0_around_ee, space0_before_e, space0_e};
 use crate::keyword;
 use crate::parser::{
-    allocated, backtrackable, not_e, optional, specialize, specialize_ref, word1, word2,
-    ParseResult, Parser,
+    allocated, backtrackable, optional, specialize, specialize_ref, word1, word2, ParseResult,
+    Parser,
     Progress::{self, *},
-    State, SyntaxError, TApply, TInParens, TRecord, TTagUnion, TVariable, Type,
+    State, SyntaxError, TApply, TInParens, TRecord, TTagUnion, Type,
 };
 use bumpalo::collections::vec::Vec;
 use bumpalo::Bump;
@@ -60,7 +60,7 @@ fn term<'a>(min_indent: u16) -> impl Parser<'a, Located<TypeAnnotation<'a>>, Typ
                 loc!(specialize(Type::TRecord, record_type(min_indent))),
                 loc!(specialize(Type::TTagUnion, tag_union_type(min_indent))),
                 loc!(applied_type(min_indent)),
-                loc!(specialize(Type::TVariable, parse_type_variable))
+                loc!(parse_type_variable)
             ),
             // Inline alias notation, e.g. [ Nil, Cons a (List a) ] as List a
             one_of![
@@ -115,21 +115,13 @@ fn loc_applied_arg<'a>(min_indent: u16) -> impl Parser<'a, Located<TypeAnnotatio
     map_with_arena!(
         and!(
             backtrackable(space0_e(min_indent, Type::TSpace, Type::TIndentStart)),
-            skip_first!(
-                // Once we hit an "as", stop parsing args
-                // and roll back parsing of preceding spaces
-                not_e(
-                    crate::parser::keyword_e(keyword::AS, Type::TStart),
-                    Type::TStart
-                ),
-                one_of!(
-                    loc_wildcard(),
-                    specialize(Type::TInParens, loc_type_in_parens(min_indent)),
-                    loc!(specialize(Type::TRecord, record_type(min_indent))),
-                    loc!(specialize(Type::TTagUnion, tag_union_type(min_indent))),
-                    loc!(specialize(Type::TApply, parse_concrete_type)),
-                    loc!(specialize(Type::TVariable, parse_type_variable))
-                )
+            one_of!(
+                loc_wildcard(),
+                specialize(Type::TInParens, loc_type_in_parens(min_indent)),
+                loc!(specialize(Type::TRecord, record_type(min_indent))),
+                loc!(specialize(Type::TTagUnion, tag_union_type(min_indent))),
+                loc!(specialize(Type::TApply, parse_concrete_type)),
+                loc!(parse_type_variable)
             )
         ),
         |arena: &'a Bump, (spaces, argument): (&'a [_], Located<TypeAnnotation<'a>>)| {
@@ -457,7 +449,7 @@ fn parse_concrete_type<'a>(
 fn parse_type_variable<'a>(
     arena: &'a Bump,
     state: State<'a>,
-) -> ParseResult<'a, TypeAnnotation<'a>, TVariable> {
+) -> ParseResult<'a, TypeAnnotation<'a>, Type<'a>> {
     match crate::ident::lowercase_ident().parse(arena, state) {
         Ok((_, name, state)) => {
             let answer = TypeAnnotation::BoundVariable(name);
@@ -466,7 +458,7 @@ fn parse_type_variable<'a>(
         }
         Err((progress, _, state)) => Err((
             progress,
-            TVariable::StartNotLowercase(state.line, state.column),
+            Type::TBadTypeVariable(state.line, state.column),
             state,
         )),
     }
diff --git a/compiler/reporting/src/error/parse.rs b/compiler/reporting/src/error/parse.rs
index f0bdeafe68..1a46b03b87 100644
--- a/compiler/reporting/src/error/parse.rs
+++ b/compiler/reporting/src/error/parse.rs
@@ -1752,7 +1752,6 @@ fn to_type_report<'a>(
         }
 
         Type::TAsIndentStart(row, col) => {
-            dbg!(row, col);
             let surroundings = Region::from_rows_cols(start_row, start_col, *row, *col);
             let region = Region::from_row_col(*row, *col);
 

From cba55734cb7b449ba198a9347e64dcbe187e0f16 Mon Sep 17 00:00:00 2001
From: Folkert <folkert@folkertdev.nl>
Date: Fri, 12 Mar 2021 03:41:01 +0100
Subject: [PATCH 72/74] clean up helpers

---
 compiler/can/tests/helpers/mod.rs       | 22 +---------------------
 compiler/fmt/tests/test_fmt.rs          | 14 ++------------
 compiler/parse/src/expr.rs              |  4 ++--
 compiler/parse/src/pattern.rs           | 13 +------------
 compiler/parse/src/test_helpers.rs      |  2 +-
 compiler/parse/src/type_annotation.rs   |  8 +-------
 compiler/reporting/tests/helpers/mod.rs | 24 ++----------------------
 editor/src/lang/expr.rs                 |  8 +++-----
 8 files changed, 13 insertions(+), 82 deletions(-)

diff --git a/compiler/can/tests/helpers/mod.rs b/compiler/can/tests/helpers/mod.rs
index 662ebd65b5..8540427d98 100644
--- a/compiler/can/tests/helpers/mod.rs
+++ b/compiler/can/tests/helpers/mod.rs
@@ -8,8 +8,6 @@ use roc_can::operator;
 use roc_can::scope::Scope;
 use roc_collections::all::MutMap;
 use roc_module::symbol::{IdentIds, Interns, ModuleId, ModuleIds};
-use roc_parse::ast;
-use roc_parse::parser::{State, SyntaxError};
 use roc_problem::can::Problem;
 use roc_region::all::{Located, Region};
 use roc_types::subs::{VarStore, Variable};
@@ -19,24 +17,6 @@ pub fn test_home() -> ModuleId {
     ModuleIds::default().get_or_insert(&"Test".into())
 }
 
-#[allow(dead_code)]
-pub fn parse_with<'a>(arena: &'a Bump, input: &'a str) -> Result<ast::Expr<'a>, SyntaxError<'a>> {
-    parse_loc_with(arena, input).map(|loc_expr| loc_expr.value)
-}
-
-#[allow(dead_code)]
-pub fn parse_loc_with<'a>(
-    arena: &'a Bump,
-    input: &'a str,
-) -> Result<Located<ast::Expr<'a>>, SyntaxError<'a>> {
-    let state = State::new(input.trim().as_bytes());
-
-    match roc_parse::expr::test_parse_expr(0, arena, state) {
-        Ok((loc_expr, _state)) => Ok(loc_expr),
-        Err(fail) => Err(SyntaxError::Expr(fail)),
-    }
-}
-
 #[allow(dead_code)]
 pub fn can_expr(expr_str: &str) -> CanExprOut {
     can_expr_with(&Bump::new(), test_home(), expr_str)
@@ -54,7 +34,7 @@ pub struct CanExprOut {
 
 #[allow(dead_code)]
 pub fn can_expr_with(arena: &Bump, home: ModuleId, expr_str: &str) -> CanExprOut {
-    let loc_expr = parse_loc_with(&arena, expr_str).unwrap_or_else(|e| {
+    let loc_expr = roc_parse::test_helpers::parse_loc_with(&arena, expr_str).unwrap_or_else(|e| {
         panic!(
             "can_expr_with() got a parse error when attempting to canonicalize:\n\n{:?} {:?}",
             expr_str, e
diff --git a/compiler/fmt/tests/test_fmt.rs b/compiler/fmt/tests/test_fmt.rs
index bda88c82f9..151dd27635 100644
--- a/compiler/fmt/tests/test_fmt.rs
+++ b/compiler/fmt/tests/test_fmt.rs
@@ -12,25 +12,15 @@ mod test_fmt {
     use roc_fmt::annotation::{Formattable, Newlines, Parens};
     use roc_fmt::def::fmt_def;
     use roc_fmt::module::fmt_module;
-    use roc_parse::ast::Expr;
     use roc_parse::module::{self, module_defs};
-    use roc_parse::parser::{Parser, State, SyntaxError};
-
-    fn parse_with<'a>(arena: &'a Bump, input: &'a str) -> Result<Expr<'a>, SyntaxError<'a>> {
-        let state = State::new(input.trim().as_bytes());
-
-        match roc_parse::expr::test_parse_expr(0, arena, state) {
-            Ok((loc_expr, _state)) => Ok(loc_expr.value),
-            Err(fail) => Err(SyntaxError::Expr(fail)),
-        }
-    }
+    use roc_parse::parser::{Parser, State};
 
     fn expr_formats_to(input: &str, expected: &str) {
         let arena = Bump::new();
         let input = input.trim_end();
         let expected = expected.trim_end();
 
-        match parse_with(&arena, input) {
+        match roc_parse::test_helpers::parse_expr_with(&arena, input.trim()) {
             Ok(actual) => {
                 let mut buf = String::new_in(&arena);
 
diff --git a/compiler/parse/src/expr.rs b/compiler/parse/src/expr.rs
index 5aa810b7b8..8c7da493b5 100644
--- a/compiler/parse/src/expr.rs
+++ b/compiler/parse/src/expr.rs
@@ -23,7 +23,7 @@ pub fn test_parse_expr<'a>(
     min_indent: u16,
     arena: &'a bumpalo::Bump,
     state: State<'a>,
-) -> Result<(Located<Expr<'a>>, State<'a>), EExpr<'a>> {
+) -> Result<Located<Expr<'a>>, EExpr<'a>> {
     let parser = space0_before_e(
         loc!(|a, s| parse_expr_help(min_indent, a, s)),
         min_indent,
@@ -32,7 +32,7 @@ pub fn test_parse_expr<'a>(
     );
 
     match parser.parse(arena, state) {
-        Ok((_, expression, state)) => Ok((expression, state)),
+        Ok((_, expression, _)) => Ok(expression),
         Err((_, fail, _)) => Err(fail),
     }
 }
diff --git a/compiler/parse/src/pattern.rs b/compiler/parse/src/pattern.rs
index 781fc4afc3..b27875f9ad 100644
--- a/compiler/parse/src/pattern.rs
+++ b/compiler/parse/src/pattern.rs
@@ -4,7 +4,7 @@ use crate::ident::{lowercase_ident, parse_ident_help, Ident};
 use crate::parser::Progress::{self, *};
 use crate::parser::{
     backtrackable, optional, specialize, specialize_ref, word1, EPattern, PInParens, PRecord,
-    ParseResult, Parser, State, SyntaxError,
+    ParseResult, Parser, State,
 };
 use bumpalo::collections::string::String;
 use bumpalo::collections::Vec;
@@ -290,10 +290,6 @@ fn loc_ident_pattern_help<'a>(
     }
 }
 
-pub fn underscore_pattern<'a>() -> impl Parser<'a, Pattern<'a>, SyntaxError<'a>> {
-    specialize(|e, _, _| SyntaxError::Pattern(e), underscore_pattern_help())
-}
-
 fn underscore_pattern_help<'a>() -> impl Parser<'a, Pattern<'a>, EPattern<'a>> {
     move |arena: &'a Bump, state: State<'a>| {
         let (_, _, next_state) = word1(b'_', EPattern::Underscore).parse(arena, state)?;
@@ -318,13 +314,6 @@ fn lowercase_ident_pattern<'a>(
     specialize(move |_, _, _| EPattern::End(row, col), lowercase_ident()).parse(arena, state)
 }
 
-pub fn record_pattern<'a>(min_indent: u16) -> impl Parser<'a, Pattern<'a>, SyntaxError<'a>> {
-    specialize(
-        |e, r, c| SyntaxError::Pattern(EPattern::Record(e, r, c)),
-        record_pattern_help(min_indent),
-    )
-}
-
 #[inline(always)]
 fn record_pattern_help<'a>(min_indent: u16) -> impl Parser<'a, Pattern<'a>, PRecord<'a>> {
     move |arena, state| {
diff --git a/compiler/parse/src/test_helpers.rs b/compiler/parse/src/test_helpers.rs
index e70782358f..a1b34105b8 100644
--- a/compiler/parse/src/test_helpers.rs
+++ b/compiler/parse/src/test_helpers.rs
@@ -32,7 +32,7 @@ pub fn parse_loc_with<'a>(
     let state = State::new(input.trim().as_bytes());
 
     match crate::expr::test_parse_expr(0, arena, state) {
-        Ok((loc_expr, _state)) => Ok(loc_expr),
+        Ok(loc_expr) => Ok(loc_expr),
         Err(fail) => Err(SyntaxError::Expr(fail)),
     }
 }
diff --git a/compiler/parse/src/type_annotation.rs b/compiler/parse/src/type_annotation.rs
index 9cc07f713a..b540775c0e 100644
--- a/compiler/parse/src/type_annotation.rs
+++ b/compiler/parse/src/type_annotation.rs
@@ -5,18 +5,12 @@ use crate::parser::{
     allocated, backtrackable, optional, specialize, specialize_ref, word1, word2, ParseResult,
     Parser,
     Progress::{self, *},
-    State, SyntaxError, TApply, TInParens, TRecord, TTagUnion, Type,
+    State, TApply, TInParens, TRecord, TTagUnion, Type,
 };
 use bumpalo::collections::vec::Vec;
 use bumpalo::Bump;
 use roc_region::all::{Located, Region};
 
-pub fn located<'a>(
-    min_indent: u16,
-) -> impl Parser<'a, Located<TypeAnnotation<'a>>, SyntaxError<'a>> {
-    specialize(|x, _, _| SyntaxError::Type(x), expression(min_indent))
-}
-
 pub fn located_help<'a>(min_indent: u16) -> impl Parser<'a, Located<TypeAnnotation<'a>>, Type<'a>> {
     expression(min_indent)
 }
diff --git a/compiler/reporting/tests/helpers/mod.rs b/compiler/reporting/tests/helpers/mod.rs
index f5f8d128cb..3cade3ded1 100644
--- a/compiler/reporting/tests/helpers/mod.rs
+++ b/compiler/reporting/tests/helpers/mod.rs
@@ -11,8 +11,6 @@ use roc_collections::all::{ImMap, MutMap, SendSet};
 use roc_constrain::expr::constrain_expr;
 use roc_constrain::module::{constrain_imported_values, Import};
 use roc_module::symbol::{IdentIds, Interns, ModuleId, ModuleIds};
-use roc_parse::ast;
-use roc_parse::parser::{State, SyntaxError};
 use roc_problem::can::Problem;
 use roc_region::all::Located;
 use roc_solve::solve;
@@ -99,27 +97,9 @@ pub struct CanExprOut {
     pub constraint: Constraint,
 }
 
-#[allow(dead_code)]
-pub fn parse_with<'a>(arena: &'a Bump, input: &'a str) -> Result<ast::Expr<'a>, SyntaxError<'a>> {
-    parse_loc_with(arena, input).map(|loc_expr| loc_expr.value)
-}
-
-#[allow(dead_code)]
-pub fn parse_loc_with<'a>(
-    arena: &'a Bump,
-    input: &'a str,
-) -> Result<Located<ast::Expr<'a>>, SyntaxError<'a>> {
-    let state = State::new(input.trim().as_bytes());
-
-    match roc_parse::expr::test_parse_expr(0, arena, state) {
-        Ok((loc_expr, _state)) => Ok(loc_expr),
-        Err(fail) => Err(SyntaxError::Expr(fail)),
-    }
-}
-
 #[derive(Debug)]
 pub struct ParseErrOut<'a> {
-    pub fail: SyntaxError<'a>,
+    pub fail: roc_parse::parser::SyntaxError<'a>,
     pub home: ModuleId,
     pub interns: Interns,
 }
@@ -130,7 +110,7 @@ pub fn can_expr_with<'a>(
     home: ModuleId,
     expr_str: &'a str,
 ) -> Result<CanExprOut, ParseErrOut<'a>> {
-    let loc_expr = match parse_loc_with(&arena, expr_str) {
+    let loc_expr = match roc_parse::test_helpers::parse_loc_with(&arena, expr_str) {
         Ok(e) => e,
         Err(fail) => {
             let interns = Interns::default();
diff --git a/editor/src/lang/expr.rs b/editor/src/lang/expr.rs
index 1ec15169ed..5f7d60062d 100644
--- a/editor/src/lang/expr.rs
+++ b/editor/src/lang/expr.rs
@@ -234,11 +234,9 @@ pub fn str_to_expr2<'a>(
     scope: &mut Scope,
     region: Region,
 ) -> Result<(Expr2, self::Output), SyntaxError<'a>> {
-    let state = State::new(input.trim().as_bytes());
-
-    match roc_parse::expr::test_parse_expr(0, arena, state) {
-        Ok((loc_expr, _state)) => Ok(to_expr2(env, scope, arena.alloc(loc_expr.value), region)),
-        Err(fail) => Err(SyntaxError::Expr(fail)),
+    match roc_parse::test_helpers::parse_loc_with(arena, input.trim()) {
+        Ok(loc_expr) => Ok(to_expr2(env, scope, arena.alloc(loc_expr.value), region)),
+        Err(fail) => Err(fail),
     }
 }
 

From f5f98b2400a22824bebdce8720a02626bcf094e8 Mon Sep 17 00:00:00 2001
From: Folkert <folkert@folkertdev.nl>
Date: Fri, 12 Mar 2021 03:43:39 +0100
Subject: [PATCH 73/74] clippy

---
 compiler/parse/src/blankspace.rs | 14 ++++++--------
 compiler/parse/src/parser.rs     |  4 ++--
 2 files changed, 8 insertions(+), 10 deletions(-)

diff --git a/compiler/parse/src/blankspace.rs b/compiler/parse/src/blankspace.rs
index 02c2bd2da8..03ae66d3e5 100644
--- a/compiler/parse/src/blankspace.rs
+++ b/compiler/parse/src/blankspace.rs
@@ -201,8 +201,6 @@ pub fn spaces_till_end_of_line<'a, E: 'a>(
                             state.bytes = &bytes[width..];
                         }
 
-                        dbg!(comment, &state);
-
                         return Ok((MadeProgress, Some(comment), state));
                     }
                     Err(_) => unreachable!("we check the first character is a #"),
@@ -227,7 +225,7 @@ pub fn spaces_till_end_of_line<'a, E: 'a>(
     }
 }
 
-fn chomp_line_comment<'a>(buffer: &'a [u8]) -> Result<&'a str, Progress> {
+fn chomp_line_comment(buffer: &[u8]) -> Result<&str, Progress> {
     if let Some(b'#') = buffer.get(0) {
         if (&buffer[1..]).starts_with(b"# ") {
             // this is a doc comment, not a line comment
@@ -257,11 +255,11 @@ fn chomp_line_comment<'a>(buffer: &'a [u8]) -> Result<&'a str, Progress> {
 
 /// Advance the parser while also indenting as appropriate.
 /// This assumes we are only advancing with spaces, since they can indent.
-fn advance_spaces_e<'a, TE, E>(
-    state: State<'a>,
+fn advance_spaces_e<TE, E>(
+    state: State,
     spaces: usize,
     to_error: TE,
-) -> Result<State<'a>, (Progress, E, State<'a>)>
+) -> Result<State, (Progress, E, State)>
 where
     TE: Fn(Row, Col) -> E,
 {
@@ -424,7 +422,7 @@ fn eat_spaces<'a>(
         }
     }
 
-    return Good {
+    Good {
         row,
         col,
         bytes,
@@ -498,7 +496,7 @@ fn eat_line_comment<'a>(
         }
     }
 
-    return Good {
+    Good {
         row,
         col,
         bytes,
diff --git a/compiler/parse/src/parser.rs b/compiler/parse/src/parser.rs
index 793c6bfdb5..b806305b07 100644
--- a/compiler/parse/src/parser.rs
+++ b/compiler/parse/src/parser.rs
@@ -1057,7 +1057,7 @@ where
     move |arena: &'a Bump, state: State<'a>| {
         // We have to clone this because if the optional parser fails,
         // we need to revert back to the original state.
-        let original_state = state.clone();
+        let original_state = state;
 
         match parser.parse(arena, state) {
             Ok((progress, out1, state)) => Ok((progress, Some(out1), state)),
@@ -1686,7 +1686,7 @@ where
     Error: 'a,
 {
     move |arena: &'a Bump, state: State<'a>| {
-        let old_state = state.clone();
+        let old_state = state;
 
         match parser.parse(arena, state) {
             Ok((_, a, s1)) => Ok((NoProgress, a, s1)),

From fd5ab353db0fad22addf92712d41775977716490 Mon Sep 17 00:00:00 2001
From: Folkert <folkert@folkertdev.nl>
Date: Fri, 12 Mar 2021 03:44:03 +0100
Subject: [PATCH 74/74] clippy

---
 compiler/parse/src/blankspace.rs             | 4 ++--
 compiler/parse/src/expr.rs                   | 2 +-
 compiler/parse/src/ident.rs                  | 8 ++++----
 compiler/parse/src/pattern.rs                | 2 +-
 compiler/reporting/src/error/canonicalize.rs | 4 ++--
 5 files changed, 10 insertions(+), 10 deletions(-)

diff --git a/compiler/parse/src/blankspace.rs b/compiler/parse/src/blankspace.rs
index 03ae66d3e5..8fd5dac813 100644
--- a/compiler/parse/src/blankspace.rs
+++ b/compiler/parse/src/blankspace.rs
@@ -427,7 +427,7 @@ fn eat_spaces<'a>(
         col,
         bytes,
         comments_and_newlines,
-    };
+    }
 }
 
 fn eat_line_comment<'a>(
@@ -501,5 +501,5 @@ fn eat_line_comment<'a>(
         col,
         bytes,
         comments_and_newlines,
-    };
+    }
 }
diff --git a/compiler/parse/src/expr.rs b/compiler/parse/src/expr.rs
index 8c7da493b5..88475f39e3 100644
--- a/compiler/parse/src/expr.rs
+++ b/compiler/parse/src/expr.rs
@@ -509,7 +509,7 @@ fn parse_expr_help<'a>(
     ]
     .parse(arena, state)?;
 
-    let initial = state.clone();
+    let initial = state;
 
     match space0_e(min_indent, EExpr::Space, EExpr::IndentEnd).parse(arena, state) {
         Err((_, _, state)) => Ok((MadeProgress, loc_expr1.value, state)),
diff --git a/compiler/parse/src/ident.rs b/compiler/parse/src/ident.rs
index a22c2348e2..21c55123f1 100644
--- a/compiler/parse/src/ident.rs
+++ b/compiler/parse/src/ident.rs
@@ -142,7 +142,7 @@ pub fn parse_ident_help<'a>(
     arena: &'a Bump,
     state: State<'a>,
 ) -> ParseResult<'a, Ident<'a>, EExpr<'a>> {
-    let initial = state.clone();
+    let initial = state;
 
     match parse_ident_help_help(arena, state) {
         Ok((progress, ident, state)) => {
@@ -192,7 +192,7 @@ fn malformed_identifier<'a>(
 }
 
 /// skip forward to the next non-identifier character
-pub fn chomp_malformed<'a>(bytes: &'a [u8]) -> usize {
+pub fn chomp_malformed(bytes: &[u8]) -> usize {
     use encode_unicode::CharExt;
     let mut chomped = 0;
     while let Ok((ch, width)) = char::from_utf8_slice_start(&bytes[chomped..]) {
@@ -427,7 +427,7 @@ fn chomp_identifier_chain<'a>(
     }
 }
 
-fn chomp_module_chain<'a>(buffer: &'a [u8]) -> Result<u16, Progress> {
+fn chomp_module_chain(buffer: &[u8]) -> Result<u16, Progress> {
     let mut chomped = 0;
 
     while let Some(b'.') = buffer.get(chomped) {
@@ -463,7 +463,7 @@ pub fn concrete_type<'a>() -> impl Parser<'a, (&'a str, &'a str), ()> {
 }
 
 // parse a type name like `Result` or `Result.Result`
-fn chomp_concrete_type<'a>(buffer: &'a [u8]) -> Result<(&'a str, &'a str, usize), Progress> {
+fn chomp_concrete_type(buffer: &[u8]) -> Result<(&str, &str, usize), Progress> {
     let first = crate::ident::chomp_uppercase_part(buffer)?;
 
     if let Some(b'.') = buffer.get(first.len()) {
diff --git a/compiler/parse/src/pattern.rs b/compiler/parse/src/pattern.rs
index b27875f9ad..50883f5352 100644
--- a/compiler/parse/src/pattern.rs
+++ b/compiler/parse/src/pattern.rs
@@ -169,7 +169,7 @@ fn loc_ident_pattern_help<'a>(
     can_have_arguments: bool,
 ) -> impl Parser<'a, Located<Pattern<'a>>, EPattern<'a>> {
     move |arena: &'a Bump, state: State<'a>| {
-        let original_state = state.clone();
+        let original_state = state;
 
         let (_, loc_ident, state) =
             specialize(|_, r, c| EPattern::Start(r, c), loc!(parse_ident_help))
diff --git a/compiler/reporting/src/error/canonicalize.rs b/compiler/reporting/src/error/canonicalize.rs
index dd380e4866..9ccd46c4c0 100644
--- a/compiler/reporting/src/error/canonicalize.rs
+++ b/compiler/reporting/src/error/canonicalize.rs
@@ -617,13 +617,13 @@ fn what_is_next<'a>(source_lines: &'a [&'a str], row: Row, col: Col) -> BadIdent
     }
 }
 
-fn till_whitespace<I>(mut it: I) -> usize
+fn till_whitespace<I>(it: I) -> usize
 where
     I: Iterator<Item = char>,
 {
     let mut chomped = 0;
 
-    while let Some(c) = it.next() {
+    for c in it {
         if c.is_ascii_whitespace() || c == '#' {
             break;
         } else {