diff --git a/Cargo.lock b/Cargo.lock
index 90caef9987..8f31623d24 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -2,9 +2,9 @@
 # It is not intended for manual editing.
 [[package]]
 name = "ab_glyph"
-version = "0.2.6"
+version = "0.2.9"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "26a685fe66654266f321a8b572660953f4df36a2135706503a4c89981d76e1a2"
+checksum = "65b1f87418ab9d7e1ee2a783aa167767ebeb316d0a9fb10c347aec28a5008acb"
 dependencies = [
  "ab_glyph_rasterizer",
  "owned_ttf_parser",
@@ -18,9 +18,9 @@ checksum = "d9fe5e32de01730eb1f6b7f5b51c17e03e2325bf40a74f754f04f130043affff"
 
 [[package]]
 name = "addr2line"
-version = "0.14.0"
+version = "0.14.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7c0929d69e78dd9bf5408269919fcbcaeb2e35e5d43e5815517cdc6a8e11a423"
+checksum = "a55f82cfe485775d02112886f4169bde0c5894d75e79ead7eafe7e40a25e45f7"
 dependencies = [
  "gimli",
 ]
@@ -94,12 +94,6 @@ dependencies = [
  "pretty_assertions",
 ]
 
-[[package]]
-name = "arrayref"
-version = "0.3.6"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a4c527152e37cf757a3f78aae5a06fbeefdb07ccc535c980a3208ee3060dd544"
-
 [[package]]
 name = "arraystring"
 version = "0.3.0"
@@ -149,24 +143,18 @@ checksum = "cdb031dd78e28731d87d56cc8ffef4a8f36ca26c38fe2de700543e627f8a464a"
 
 [[package]]
 name = "backtrace"
-version = "0.3.55"
+version = "0.3.56"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ef5140344c85b01f9bbb4d4b7288a8aa4b3287ccef913a14bcc78a1063623598"
+checksum = "9d117600f438b1707d4e4ae15d3595657288f8235a0eb593e80ecc98ab34e1bc"
 dependencies = [
  "addr2line",
  "cfg-if 1.0.0",
  "libc",
  "miniz_oxide",
- "object",
+ "object 0.23.0",
  "rustc-demangle",
 ]
 
-[[package]]
-name = "base64"
-version = "0.13.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "904dfeac50f3cdaba28fc6f57fdcddb75f49ed61346676a78c4ffe55877802fd"
-
 [[package]]
 name = "bit-set"
 version = "0.5.2"
@@ -197,17 +185,6 @@ dependencies = [
  "typenum",
 ]
 
-[[package]]
-name = "blake2b_simd"
-version = "0.5.11"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "afa748e348ad3be8263be728124b24a24f268266f6f5d58af9d75f6a40b5c587"
-dependencies = [
- "arrayref",
- "arrayvec",
- "constant_time_eq",
-]
-
 [[package]]
 name = "block"
 version = "0.1.6"
@@ -237,9 +214,9 @@ dependencies = [
 
 [[package]]
 name = "bstr"
-version = "0.2.14"
+version = "0.2.15"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "473fc6b38233f9af7baa94fb5852dca389e3d95b8e21c8e3719301462c5d9faf"
+checksum = "a40b47ad93e1a5404e6c18dec46b628214fee441c70f4ab5d6942142cc268a3d"
 dependencies = [
  "lazy_static",
  "memchr",
@@ -249,9 +226,9 @@ dependencies = [
 
 [[package]]
 name = "bumpalo"
-version = "3.4.0"
+version = "3.6.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2e8c087f005730276d1096a652e92a8bacee2e2472bcc9715a74d2bec38b5820"
+checksum = "099e596ef14349721d9016f6b80dd3419ea1bf289ab9b44df8e4dfd3a005d5d9"
 
 [[package]]
 name = "byte-tools"
@@ -261,9 +238,9 @@ checksum = "e3b5ca7a04898ad4bcd41c90c5285445ff5b791899bb1b0abdd2a2aa791211d7"
 
 [[package]]
 name = "bytemuck"
-version = "1.4.1"
+version = "1.5.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "41aa2ec95ca3b5c54cf73c91acf06d24f4495d5f1b1c12506ae3483d646177ac"
+checksum = "5a4bad0c5981acc24bc09e532f35160f952e35422603f0563cd7a73c2c2e65a0"
 dependencies = [
  "bytemuck_derive",
 ]
@@ -275,15 +252,15 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "8e215f8c2f9f79cb53c8335e687ffd07d5bfcb6fe5fc80723762d0be46e7cc54"
 dependencies = [
  "proc-macro2 1.0.24",
- "quote 1.0.7",
- "syn 1.0.53",
+ "quote 1.0.8",
+ "syn 1.0.60",
 ]
 
 [[package]]
 name = "byteorder"
-version = "1.3.4"
+version = "1.4.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "08c48aae112d48ed9f069b33538ea9e3e90aa263cfa3d1c24309612b1f7472de"
+checksum = "ae44d1a3d5a19df61dd0c8beb138458ac2a53a7ac09eba97d55592540004306b"
 
 [[package]]
 name = "bytes"
@@ -379,8 +356,8 @@ dependencies = [
  "heck",
  "proc-macro-error",
  "proc-macro2 1.0.24",
- "quote 1.0.7",
- "syn 1.0.53",
+ "quote 1.0.8",
+ "syn 1.0.60",
 ]
 
 [[package]]
@@ -402,15 +379,6 @@ dependencies = [
  "bitflags",
 ]
 
-[[package]]
-name = "cloudabi"
-version = "0.1.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4344512281c643ae7638bbabc3af17a11307803ec8f0fcad9fae512a8bf36467"
-dependencies = [
- "bitflags",
-]
-
 [[package]]
 name = "cocoa"
 version = "0.20.2"
@@ -454,15 +422,15 @@ dependencies = [
 
 [[package]]
 name = "const_fn"
-version = "0.4.3"
+version = "0.4.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c478836e029dcef17fb47c89023448c64f781a046e0300e257ad8225ae59afab"
+checksum = "28b9d6de7f49e22cf97ad17fc4036ece69300032f45f78f30b4a4482cdc3f4a6"
 
 [[package]]
 name = "const_format"
-version = "0.2.10"
+version = "0.2.13"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "25f84a8cfc8f74c1deb4bd7b2a41a669cab38327679491a30e19266f349ceaa0"
+checksum = "c0412fd9e3c921f868af82a0097da41c250087e513786858b9e6b6055f8ed300"
 dependencies = [
  "const_format_proc_macros",
 ]
@@ -474,16 +442,10 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "8df496e1bbc93814d728a8036ff054cd95830afe9cf2275c9326688c02eff936"
 dependencies = [
  "proc-macro2 1.0.24",
- "quote 1.0.7",
+ "quote 1.0.8",
  "unicode-xid 0.2.1",
 ]
 
-[[package]]
-name = "constant_time_eq"
-version = "0.1.5"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "245097e9a4535ee1e3e3931fcfcd55a796a44c643e8596ff6566d68f09b87bbc"
-
 [[package]]
 name = "copyless"
 version = "0.1.5"
@@ -584,16 +546,16 @@ dependencies = [
 
 [[package]]
 name = "criterion"
-version = "0.3.3"
+version = "0.3.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "70daa7ceec6cf143990669a04c7df13391d55fb27bd4079d252fca774ba244d8"
+checksum = "ab327ed7354547cc2ef43cbe20ef68b988e70b4b593cbd66a2a61733123a3d23"
 dependencies = [
  "atty",
  "cast",
  "clap 2.33.3",
  "criterion-plot",
  "csv",
- "itertools",
+ "itertools 0.10.0",
  "lazy_static",
  "num-traits",
  "oorandom",
@@ -615,7 +577,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "e022feadec601fba1649cfa83586381a4ad31c6bf3a9ab7d408118b05dd9889d"
 dependencies = [
  "cast",
- "itertools",
+ "itertools 0.9.0",
 ]
 
 [[package]]
@@ -771,13 +733,13 @@ dependencies = [
 
 [[package]]
 name = "derivative"
-version = "2.1.1"
+version = "2.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "cb582b60359da160a9477ee80f15c8d784c477e69c217ef2cdd4169c24ea380f"
+checksum = "fcc3dd5e9e9c0b295d6e1e4d811fb6f157d5ffd784b8d202fc62eac8035a770b"
 dependencies = [
  "proc-macro2 1.0.24",
- "quote 1.0.7",
- "syn 1.0.53",
+ "quote 1.0.8",
+ "syn 1.0.60",
 ]
 
 [[package]]
@@ -796,19 +758,20 @@ dependencies = [
 ]
 
 [[package]]
-name = "dirs"
-version = "3.0.1"
+name = "dirs-next"
+version = "2.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "142995ed02755914747cc6ca76fc7e4583cd18578746716d0508ea6ed558b9ff"
+checksum = "b98cf8ebf19c3d1b223e151f99a4f9f0690dca41414773390fc824184ac833e1"
 dependencies = [
- "dirs-sys",
+ "cfg-if 1.0.0",
+ "dirs-sys-next",
 ]
 
 [[package]]
-name = "dirs-sys"
-version = "0.3.5"
+name = "dirs-sys-next"
+version = "0.1.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8e93d7f5705de3e49895a2b5e0b8855a1c27f080192ae9c32a6432d50741a57a"
+checksum = "4ebda144c4fe02d1f7ea1a7d9641b6fc6b580adcfa024ae48797ecdeb6825b4d"
 dependencies = [
  "libc",
  "redox_users",
@@ -915,9 +878,9 @@ checksum = "37ab347416e802de484e4d03c7316c48f1ecb56574dfd4a46a80f173ce1de04d"
 
 [[package]]
 name = "flate2"
-version = "1.0.19"
+version = "1.0.20"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7411863d55df97a419aa64cb4d2f167103ea9d767e2c54a1868b7ac3f6b47129"
+checksum = "cd3aec53de10fe96d7d8c565eb17f2c687bb5518a2ec453b5b1252964526abe0"
 dependencies = [
  "cfg-if 1.0.0",
  "crc32fast",
@@ -986,9 +949,9 @@ checksum = "3dcaa9ae7725d12cdb85b3ad99a434db70b468c09ded17e012d86b5c1010f7a7"
 
 [[package]]
 name = "futures"
-version = "0.3.8"
+version = "0.3.12"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9b3b0c040a1fe6529d30b3c5944b280c7f0dcb2930d2c3062bca967b602583d0"
+checksum = "da9052a1a50244d8d5aa9bf55cbc2fb6f357c86cc52e46c62ed390a7180cf150"
 dependencies = [
  "futures-channel",
  "futures-core",
@@ -1001,9 +964,9 @@ dependencies = [
 
 [[package]]
 name = "futures-channel"
-version = "0.3.8"
+version = "0.3.12"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4b7109687aa4e177ef6fe84553af6280ef2778bdb7783ba44c9dc3399110fe64"
+checksum = "f2d31b7ec7efab6eefc7c57233bb10b847986139d88cc2f5a02a1ae6871a1846"
 dependencies = [
  "futures-core",
  "futures-sink",
@@ -1011,15 +974,15 @@ dependencies = [
 
 [[package]]
 name = "futures-core"
-version = "0.3.8"
+version = "0.3.12"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "847ce131b72ffb13b6109a221da9ad97a64cbe48feb1028356b836b47b8f1748"
+checksum = "79e5145dde8da7d1b3892dad07a9c98fc04bc39892b1ecc9692cf53e2b780a65"
 
 [[package]]
 name = "futures-executor"
-version = "0.3.8"
+version = "0.3.12"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4caa2b2b68b880003057c1dd49f1ed937e38f22fcf6c212188a121f08cf40a65"
+checksum = "e9e59fdc009a4b3096bf94f740a0f2424c082521f20a9b08c5c07c48d90fd9b9"
 dependencies = [
  "futures-core",
  "futures-task",
@@ -1028,42 +991,42 @@ dependencies = [
 
 [[package]]
 name = "futures-io"
-version = "0.3.8"
+version = "0.3.12"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "611834ce18aaa1bd13c4b374f5d653e1027cf99b6b502584ff8c9a64413b30bb"
+checksum = "28be053525281ad8259d47e4de5de657b25e7bac113458555bb4b70bc6870500"
 
 [[package]]
 name = "futures-macro"
-version = "0.3.8"
+version = "0.3.12"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "77408a692f1f97bcc61dc001d752e00643408fbc922e4d634c655df50d595556"
+checksum = "c287d25add322d9f9abdcdc5927ca398917996600182178774032e9f8258fedd"
 dependencies = [
  "proc-macro-hack",
  "proc-macro2 1.0.24",
- "quote 1.0.7",
- "syn 1.0.53",
+ "quote 1.0.8",
+ "syn 1.0.60",
 ]
 
 [[package]]
 name = "futures-sink"
-version = "0.3.8"
+version = "0.3.12"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f878195a49cee50e006b02b93cf7e0a95a38ac7b776b4c4d9cc1207cd20fcb3d"
+checksum = "caf5c69029bda2e743fddd0582d1083951d65cc9539aebf8812f36c3491342d6"
 
 [[package]]
 name = "futures-task"
-version = "0.3.8"
+version = "0.3.12"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7c554eb5bf48b2426c4771ab68c6b14468b6e76cc90996f528c3338d761a4d0d"
+checksum = "13de07eb8ea81ae445aca7b69f5f7bf15d7bf4912d8ca37d6645c77ae8a58d86"
 dependencies = [
  "once_cell",
 ]
 
 [[package]]
 name = "futures-util"
-version = "0.3.8"
+version = "0.3.12"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d304cff4a7b99cfb7986f7d43fbe93d175e72e704a8860787cc95e9ffd85cbd2"
+checksum = "632a8cd0f2a4b3fdea1657f08bde063848c3bd00f9bbf6e256b8be78802e624b"
 dependencies = [
  "futures-channel",
  "futures-core",
@@ -1072,7 +1035,7 @@ dependencies = [
  "futures-sink",
  "futures-task",
  "memchr",
- "pin-project",
+ "pin-project-lite 0.2.4",
  "pin-utils",
  "proc-macro-hack",
  "proc-macro-nested",
@@ -1099,24 +1062,24 @@ dependencies = [
 
 [[package]]
 name = "getrandom"
-version = "0.1.15"
+version = "0.1.16"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "fc587bc0ec293155d5bfa6b9891ec18a1e330c234f896ea47fbada4cadbe47e6"
+checksum = "8fc3cb4d91f53b50155bdcfd23f6a4c39ae1969c2ae85982b135750cccaf5fce"
 dependencies = [
- "cfg-if 0.1.10",
+ "cfg-if 1.0.0",
  "libc",
  "wasi 0.9.0+wasi-snapshot-preview1",
 ]
 
 [[package]]
 name = "getrandom"
-version = "0.2.1"
+version = "0.2.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4060f4657be78b8e766215b02b18a2e862d83745545de804638e2b545e81aee6"
+checksum = "c9495705279e7140bf035dde1f6e750c162df8b625267cd52cc44e0b156732c8"
 dependencies = [
  "cfg-if 1.0.0",
  "libc",
- "wasi 0.10.1+wasi-snapshot-preview1",
+ "wasi 0.10.2+wasi-snapshot-preview1",
 ]
 
 [[package]]
@@ -1273,23 +1236,23 @@ checksum = "f6503fe142514ca4799d4c26297c4248239fe8838d827db6bd6065c6ed29a6ce"
 
 [[package]]
 name = "glyph_brush"
-version = "0.7.0"
+version = "0.7.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "afd3e2cfd503a5218dd56172a8bf7c8655a4a7cf745737c606a6edfeea1b343f"
+checksum = "3e3f00b8574a76fb6c50890c48da03946ca50e4372a2778737922666a2238221"
 dependencies = [
  "glyph_brush_draw_cache",
  "glyph_brush_layout",
  "log",
- "ordered-float",
+ "ordered-float 2.1.1",
  "rustc-hash",
  "twox-hash",
 ]
 
 [[package]]
 name = "glyph_brush_draw_cache"
-version = "0.1.3"
+version = "0.1.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8cef969a091be5565c2c10b31fd2f115cbeed9f783a27c96ae240ff8ceee067c"
+checksum = "ac2c82074cafb68b9e459c50c655f7eedcb92d6ee7166813802934bc6fc29fa3"
 dependencies = [
  "ab_glyph",
  "crossbeam-channel 0.5.0",
@@ -1312,15 +1275,15 @@ dependencies = [
 
 [[package]]
 name = "half"
-version = "1.6.0"
+version = "1.7.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d36fab90f82edc3c747f9d438e06cf0a491055896f2a279638bb5beed6c40177"
+checksum = "62aca2aba2d62b4a7f5b33f3712cb1b0692779a56fb510499d5c0aa594daeaf3"
 
 [[package]]
 name = "handlebars"
-version = "3.5.1"
+version = "3.5.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2764f9796c0ddca4b82c07f25dd2cb3db30b9a8f47940e78e1c883d9e95c3db9"
+checksum = "964d0e99a61fe9b1b347389b77ebf8b7e1587b70293676aaca7d27e59b9073b2"
 dependencies = [
  "log",
  "pest",
@@ -1338,18 +1301,18 @@ checksum = "d7afe4a420e3fe79967a00898cc1f4db7c8a49a9333a29f8a4bd76a253d5cd04"
 
 [[package]]
 name = "heck"
-version = "0.3.1"
+version = "0.3.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "20564e78d53d2bb135c343b3f47714a56af2061f1c928fdb541dc7b9fdd94205"
+checksum = "87cbf45460356b7deeb5e3415b5563308c0a9b057c85e12b06ad551f98d0a6ac"
 dependencies = [
  "unicode-segmentation",
 ]
 
 [[package]]
 name = "hermit-abi"
-version = "0.1.17"
+version = "0.1.18"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5aca5565f760fb5b220e499d72710ed156fdb74e631659e99377d9ebfbd13ae8"
+checksum = "322f4de77956e22ed0e5032c359a0f1273f1f7f0d79bfa3b8ffbc730d7fbcc5c"
 dependencies = [
  "libc",
 ]
@@ -1393,9 +1356,9 @@ dependencies = [
 
 [[package]]
 name = "indexmap"
-version = "1.6.0"
+version = "1.6.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "55e2e4c765aa53a0424761bf9f41aa7a6ac1efa87238f59560640e27fca028f2"
+checksum = "4fb1fa934250de4de8aef298d81c729a7d33d8c239daa3a7575e6b92bfc7313b"
 dependencies = [
  "autocfg 1.0.1",
  "hashbrown",
@@ -1419,8 +1382,8 @@ checksum = "ce046d161f000fffde5f432a0d034d0341dc152643b2598ed5bfce44c4f3a8f0"
 dependencies = [
  "proc-macro-hack",
  "proc-macro2 1.0.24",
- "quote 1.0.7",
- "syn 1.0.53",
+ "quote 1.0.8",
+ "syn 1.0.60",
  "unindent",
 ]
 
@@ -1444,8 +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 1.0.7",
- "syn 1.0.53",
+ "quote 1.0.8",
+ "syn 1.0.60",
 ]
 
 [[package]]
@@ -1456,9 +1419,9 @@ checksum = "3094308123a0e9fd59659ce45e22de9f53fc1d2ac6e1feb9fef988e4f76cad77"
 
 [[package]]
 name = "inplace_it"
-version = "0.3.2"
+version = "0.3.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "dd01a2a73f2f399df96b22dc88ea687ef4d76226284e7531ae3c7ee1dc5cb534"
+checksum = "90953f308a79fe6d62a4643e51f848fbfddcd05975a38e69fdf4ab86a7baf7ca"
 
 [[package]]
 name = "instant"
@@ -1488,10 +1451,19 @@ dependencies = [
 ]
 
 [[package]]
-name = "itoa"
-version = "0.4.6"
+name = "itertools"
+version = "0.10.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "dc6f3ad7b9d11a0c00842ff8de1b60ee58661048eb8049ed33c73594f359d7e6"
+checksum = "37d572918e350e82412fe766d24b15e6682fb2ed2bbe018280caa810397cb319"
+dependencies = [
+ "either",
+]
+
+[[package]]
+name = "itoa"
+version = "0.4.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "dd25036021b0de88a0aff6b850051563c6516d0bf53f8638938edbb9de732736"
 
 [[package]]
 name = "jni-sys"
@@ -1510,9 +1482,9 @@ dependencies = [
 
 [[package]]
 name = "js-sys"
-version = "0.3.46"
+version = "0.3.47"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "cf3d7383929f7c9c7c2d0fa596f325832df98c3704f2c60553080f7127a58175"
+checksum = "5cfb73131c35423a367daf8cbd24100af0d077668c8c2943f0e7dd775fef0f65"
 dependencies = [
  "wasm-bindgen",
 ]
@@ -1547,15 +1519,15 @@ checksum = "830d08ce1d1d941e6b30645f1a0eb5643013d835ce3779a5fc208261dbe10f55"
 
 [[package]]
 name = "libc"
-version = "0.2.80"
+version = "0.2.85"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4d58d1b70b004888f764dfbf6a26a3b0342a1632d33968e4a179d8011c760614"
+checksum = "7ccac4b00700875e6a07c6cde370d44d32fa01c5a65cdd2fca6858c479d28bb3"
 
 [[package]]
 name = "libloading"
-version = "0.6.6"
+version = "0.6.7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e9367bdfa836b7e3cf895867f7a570283444da90562980ec2263d6e1569b16bc"
+checksum = "351a32417a12d5f7e82c368a66781e307834dae04c6ce0cd4456d52989229883"
 dependencies = [
  "cfg-if 1.0.0",
  "winapi 0.3.9",
@@ -1609,11 +1581,11 @@ dependencies = [
 
 [[package]]
 name = "log"
-version = "0.4.11"
+version = "0.4.14"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4fabed175da42fed1fa0746b0ea71f412aa9d35e76e95e59b192c64b9dc2bf8b"
+checksum = "51b9bbe6c47d51fc3e1a9b945965946b4c44142ab8792c50835a980d362c2710"
 dependencies = [
- "cfg-if 0.1.10",
+ "cfg-if 1.0.0",
 ]
 
 [[package]]
@@ -1827,9 +1799,9 @@ checksum = "2b2820aca934aba5ed91c79acc72b6a44048ceacc5d36c035ed4e051f12d887d"
 
 [[package]]
 name = "net2"
-version = "0.2.36"
+version = "0.2.37"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d7cf75f38f16cb05ea017784dc6dbfd354f76c223dba37701734c4f5a9337d02"
+checksum = "391630d12b68002ae1e25e8f974306474966550ad82dac6886fb8910c19568ae"
 dependencies = [
  "cfg-if 0.1.10",
  "libc",
@@ -1920,8 +1892,8 @@ checksum = "ffa5a33ddddfee04c0283a7653987d634e880347e96b5b2ed64de07efb59db9d"
 dependencies = [
  "proc-macro-crate",
  "proc-macro2 1.0.24",
- "quote 1.0.7",
- "syn 1.0.53",
+ "quote 1.0.8",
+ "syn 1.0.60",
 ]
 
 [[package]]
@@ -1975,6 +1947,12 @@ dependencies = [
  "wasmparser",
 ]
 
+[[package]]
+name = "object"
+version = "0.23.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a9a7ab5d64814df0fe4a4b5ead45ed6c5f181ee3ff04ba344313a6c80446c5d4"
+
 [[package]]
 name = "once_cell"
 version = "1.5.2"
@@ -1995,18 +1973,27 @@ checksum = "2839e79665f131bdb5782e51f2c6c9599c133c6098982a54c794358bf432529c"
 
 [[package]]
 name = "ordered-float"
-version = "1.1.0"
+version = "1.1.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3741934be594d77de1c8461ebcbbe866f585ea616a9753aa78f2bdc69f0e4579"
+checksum = "3305af35278dd29f46fcdd139e0b1fbfae2153f0e5928b39b035542dd31e37b7"
+dependencies = [
+ "num-traits",
+]
+
+[[package]]
+name = "ordered-float"
+version = "2.1.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "766f840da25490628d8e63e529cd21c014f6600c6b8517add12a6fa6167a6218"
 dependencies = [
  "num-traits",
 ]
 
 [[package]]
 name = "owned_ttf_parser"
-version = "0.8.0"
+version = "0.11.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "fb477c7fd2a3a6e04e1dc6ca2e4e9b04f2df702021dc5a5d1cf078c587dc59f7"
+checksum = "948b27637ba56144c62d3415929ef18986b3a383137ebcbe97d9362a968bf997"
 dependencies = [
  "ttf-parser",
 ]
@@ -2039,7 +2026,7 @@ checksum = "6d7744ac029df22dca6284efe4e898991d28e3085c706c972bcd7da4a27a15eb"
 dependencies = [
  "instant",
  "lock_api 0.4.2",
- "parking_lot_core 0.8.0",
+ "parking_lot_core 0.8.2",
 ]
 
 [[package]]
@@ -2049,26 +2036,25 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "d58c7c768d4ba344e3e8d72518ac13e259d7c7ade24167003b8488e10b6740a3"
 dependencies = [
  "cfg-if 0.1.10",
- "cloudabi 0.0.3",
+ "cloudabi",
  "libc",
- "redox_syscall",
+ "redox_syscall 0.1.57",
  "smallvec",
  "winapi 0.3.9",
 ]
 
 [[package]]
 name = "parking_lot_core"
-version = "0.8.0"
+version = "0.8.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c361aa727dd08437f2f1447be8b59a33b0edd15e0fcee698f935613d9efbca9b"
+checksum = "9ccb628cad4f84851442432c60ad8e1f607e29752d0bf072cbd0baf28aa34272"
 dependencies = [
  "backtrace",
- "cfg-if 0.1.10",
- "cloudabi 0.1.0",
+ "cfg-if 1.0.0",
  "instant",
  "libc",
  "petgraph",
- "redox_syscall",
+ "redox_syscall 0.1.57",
  "smallvec",
  "thread-id",
  "winapi 0.3.9",
@@ -2108,8 +2094,8 @@ dependencies = [
  "pest",
  "pest_meta",
  "proc-macro2 1.0.24",
- "quote 1.0.7",
- "syn 1.0.53",
+ "quote 1.0.8",
+ "syn 1.0.60",
 ]
 
 [[package]]
@@ -2133,26 +2119,6 @@ dependencies = [
  "indexmap",
 ]
 
-[[package]]
-name = "pin-project"
-version = "1.0.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9ccc2237c2c489783abd8c4c80e5450fc0e98644555b1364da68cc29aa151ca7"
-dependencies = [
- "pin-project-internal",
-]
-
-[[package]]
-name = "pin-project-internal"
-version = "1.0.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f8e8d2bf0b23038a4424865103a4df472855692821aab4e4f5c3312d461d9e5f"
-dependencies = [
- "proc-macro2 1.0.24",
- "quote 1.0.7",
- "syn 1.0.53",
-]
-
 [[package]]
 name = "pin-project-lite"
 version = "0.1.11"
@@ -2161,9 +2127,9 @@ checksum = "c917123afa01924fc84bb20c4c03f004d9c38e5127e3c039bbf7f4b9c76a2f6b"
 
 [[package]]
 name = "pin-project-lite"
-version = "0.2.0"
+version = "0.2.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6b063f57ec186e6140e2b8b6921e5f1bd89c7356dda5b33acc5401203ca6131c"
+checksum = "439697af366c49a6d0a010c56a0d97685bc140ce0d377b13a2ea2aa42d64a827"
 
 [[package]]
 name = "pin-utils"
@@ -2179,16 +2145,32 @@ checksum = "3831453b3449ceb48b6d9c7ad7c96d5ea673e9b470a1dc578c2ce6521230884c"
 
 [[package]]
 name = "plotters"
-version = "0.2.15"
+version = "0.3.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0d1685fbe7beba33de0330629da9d955ac75bd54f33d7b79f9a895590124f6bb"
+checksum = "45ca0ae5f169d0917a7c7f5a9c1a3d3d9598f18f529dd2b8373ed988efea307a"
 dependencies = [
- "js-sys",
  "num-traits",
+ "plotters-backend",
+ "plotters-svg",
  "wasm-bindgen",
  "web-sys",
 ]
 
+[[package]]
+name = "plotters-backend"
+version = "0.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b07fffcddc1cb3a1de753caa4e4df03b79922ba43cf882acc1bdd7e8df9f4590"
+
+[[package]]
+name = "plotters-svg"
+version = "0.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b38a02e23bd9604b842a812063aec4ef702b57989c37b655254bb61c471ad211"
+dependencies = [
+ "plotters-backend",
+]
+
 [[package]]
 name = "ppv-lite86"
 version = "0.2.10"
@@ -2222,8 +2204,8 @@ checksum = "18f33027081eba0a6d8aba6d1b1c3a3be58cbb12106341c2d5759fcd9b5277e7"
 dependencies = [
  "proc-macro-error-attr",
  "proc-macro2 1.0.24",
- "quote 1.0.7",
- "syn 1.0.53",
+ "quote 1.0.8",
+ "syn 1.0.60",
  "version_check",
 ]
 
@@ -2234,8 +2216,8 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "8a5b4b77fdb63c1eca72173d68d24501c54ab1269409f6b672c85deb18af69de"
 dependencies = [
  "proc-macro2 1.0.24",
- "quote 1.0.7",
- "syn 1.0.53",
+ "quote 1.0.8",
+ "syn 1.0.60",
  "syn-mid",
  "version_check",
 ]
@@ -2248,9 +2230,9 @@ checksum = "dbf0c48bc1d91375ae5c3cd81e3722dff1abcf81a30960240640d223f59fe0e5"
 
 [[package]]
 name = "proc-macro-nested"
-version = "0.1.6"
+version = "0.1.7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "eba180dafb9038b050a4c280019bbedf9f2467b61e5d892dcad585bb57aadc5a"
+checksum = "bc881b2c22681370c6a780e47af9840ef841837bc98118431d4e1868bd0c1086"
 
 [[package]]
 name = "proc-macro2"
@@ -2327,9 +2309,9 @@ dependencies = [
 
 [[package]]
 name = "quote"
-version = "1.0.7"
+version = "1.0.8"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "aa563d17ecb180e500da1cfd2b028310ac758de548efdd203e18f283af693f37"
+checksum = "991431c3519a3f36861882da93630ce66b52918dcf1b8e2fd66b397fc96f28df"
 dependencies = [
  "proc-macro2 1.0.24",
 ]
@@ -2359,7 +2341,7 @@ version = "0.7.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "6a6b1679d49b24bbfe0c803429aa1874472f50d9b363131f0e89fc356b544d03"
 dependencies = [
- "getrandom 0.1.15",
+ "getrandom 0.1.16",
  "libc",
  "rand_chacha 0.2.2",
  "rand_core 0.5.1",
@@ -2368,9 +2350,9 @@ dependencies = [
 
 [[package]]
 name = "rand"
-version = "0.8.2"
+version = "0.8.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "18519b42a40024d661e1714153e9ad0c3de27cd495760ceb09710920f1098b1e"
+checksum = "0ef9e7e66b4468674bfcb0c81af8b7fa0bb154fa9f28eb840da5c447baeb8d7e"
 dependencies = [
  "libc",
  "rand_chacha 0.3.0",
@@ -2429,7 +2411,7 @@ version = "0.5.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "90bde5296fc891b0cef12a6d03ddccc162ce7b2aff54160af9338f8d40df6d19"
 dependencies = [
- "getrandom 0.1.15",
+ "getrandom 0.1.16",
 ]
 
 [[package]]
@@ -2438,7 +2420,7 @@ version = "0.6.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "c026d7df8b298d90ccbbc5190bd04d85e159eaf5576caeacf8741da93ccbd2e5"
 dependencies = [
- "getrandom 0.2.1",
+ "getrandom 0.2.2",
 ]
 
 [[package]]
@@ -2494,7 +2476,7 @@ version = "0.1.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "7b75f676a1e053fc562eafbb47838d67c84801e38fc1ba459e8f180deabd5071"
 dependencies = [
- "cloudabi 0.0.3",
+ "cloudabi",
  "fuchsia-cprng",
  "libc",
  "rand_core 0.4.2",
@@ -2532,9 +2514,9 @@ dependencies = [
 
 [[package]]
 name = "range-alloc"
-version = "0.1.1"
+version = "0.1.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a871f1e45a3a3f0c73fb60343c811238bb5143a81642e27c2ac7aac27ff01a63"
+checksum = "63e935c45e09cc6dcf00d2f0b2d630a58f4095320223d47fc68918722f0538b6"
 
 [[package]]
 name = "raw-window-handle"
@@ -2586,21 +2568,29 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "41cc0f7e4d5d4544e8861606a285bb08d3e70712ccc7d2b84d7c0ccfaf4b05ce"
 
 [[package]]
-name = "redox_users"
-version = "0.3.5"
+name = "redox_syscall"
+version = "0.2.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "de0737333e7a9502c789a36d7c7fa6092a49895d4faa31ca5df163857ded2e9d"
+checksum = "05ec8ca9416c5ea37062b502703cd7fcb207736bc294f6e0cf367ac6fc234570"
 dependencies = [
- "getrandom 0.1.15",
- "redox_syscall",
- "rust-argon2",
+ "bitflags",
+]
+
+[[package]]
+name = "redox_users"
+version = "0.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "528532f3d801c87aec9def2add9ca802fe569e44a544afe633765267840abe64"
+dependencies = [
+ "getrandom 0.2.2",
+ "redox_syscall 0.2.4",
 ]
 
 [[package]]
 name = "regex"
-version = "1.4.2"
+version = "1.4.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "38cf2c13ed4745de91a5eb834e11c00bcc3709e773173b2ce4c56c9fbde04b9c"
+checksum = "d9251239e129e16308e70d853559389de218ac275b515068abc96829d05b948a"
 dependencies = [
  "aho-corasick",
  "memchr",
@@ -2619,9 +2609,9 @@ dependencies = [
 
 [[package]]
 name = "regex-syntax"
-version = "0.6.21"
+version = "0.6.22"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3b181ba2dcf07aaccad5448e8ead58db5b742cf85dfe035e2227f137a539a189"
+checksum = "b5eb417147ba9860a96cfe72a0b93bf88fee1744b5636ec99ab20c1aa9376581"
 
 [[package]]
 name = "remove_dir_all"
@@ -2662,7 +2652,6 @@ dependencies = [
  "roc_solve",
  "roc_types",
  "roc_unify",
- "roc_uniq",
  "target-lexicon",
  "tempfile",
 ]
@@ -2741,7 +2730,6 @@ dependencies = [
  "roc_solve",
  "roc_types",
  "roc_unify",
- "roc_uniq",
  "rustyline",
  "rustyline-derive",
  "serde",
@@ -2779,7 +2767,6 @@ dependencies = [
  "roc_parse",
  "roc_region",
  "roc_types",
- "roc_uniq",
 ]
 
 [[package]]
@@ -2801,7 +2788,7 @@ dependencies = [
  "indoc",
  "inkwell",
  "inlinable_string",
- "itertools",
+ "itertools 0.9.0",
  "libc",
  "log",
  "maplit",
@@ -2811,7 +2798,7 @@ dependencies = [
  "pretty_assertions",
  "quickcheck",
  "quickcheck_macros",
- "rand 0.8.2",
+ "rand 0.8.3",
  "roc_builtins",
  "roc_can",
  "roc_collections",
@@ -2828,7 +2815,6 @@ dependencies = [
  "roc_solve",
  "roc_types",
  "roc_unify",
- "roc_uniq",
  "ropey",
  "snafu",
  "target-lexicon",
@@ -2893,7 +2879,6 @@ dependencies = [
  "roc_std",
  "roc_types",
  "roc_unify",
- "roc_uniq",
  "target-lexicon",
  "tokio",
 ]
@@ -2907,11 +2892,11 @@ dependencies = [
  "im-rc",
  "indoc",
  "inlinable_string",
- "itertools",
+ "itertools 0.9.0",
  "libc",
  "libloading",
  "maplit",
- "object",
+ "object 0.22.0",
  "pretty_assertions",
  "quickcheck",
  "quickcheck_macros",
@@ -2931,7 +2916,6 @@ dependencies = [
  "roc_std",
  "roc_types",
  "roc_unify",
- "roc_uniq",
  "target-lexicon",
  "tempfile",
  "tokio",
@@ -3136,30 +3120,6 @@ dependencies = [
  "roc_types",
 ]
 
-[[package]]
-name = "roc_uniq"
-version = "0.1.0"
-dependencies = [
- "bumpalo",
- "im",
- "im-rc",
- "indoc",
- "maplit",
- "pretty_assertions",
- "quickcheck",
- "quickcheck_macros",
- "roc_builtins",
- "roc_can",
- "roc_collections",
- "roc_constrain",
- "roc_module",
- "roc_parse",
- "roc_problem",
- "roc_region",
- "roc_solve",
- "roc_types",
-]
-
 [[package]]
 name = "ropey"
 version = "1.2.0"
@@ -3169,18 +3129,6 @@ dependencies = [
  "smallvec",
 ]
 
-[[package]]
-name = "rust-argon2"
-version = "0.8.3"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4b18820d944b33caa75a71378964ac46f58517c92b6ae5f762636247c09e78fb"
-dependencies = [
- "base64",
- "blake2b_simd",
- "constant_time_eq",
- "crossbeam-utils 0.8.1",
-]
-
 [[package]]
 name = "rustc-demangle"
 version = "0.1.18"
@@ -3218,19 +3166,19 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "9f61411055101f7b60ecf1041d87fb74205fb20b0c7a723f07ef39174cf6b4c0"
 dependencies = [
  "approx 0.3.2",
- "ordered-float",
+ "ordered-float 1.1.1",
  "stb_truetype",
 ]
 
 [[package]]
 name = "rustyline"
-version = "7.0.0"
+version = "7.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1a5f54deba50e65ee4cf786dbc37e8b3c63bdccccbcf9d3a8a9fd0c1bb7e1984"
+checksum = "8227301bfc717136f0ecbd3d064ba8199e44497a0bdd46bb01ede4387cfd2cec"
 dependencies = [
  "bitflags",
  "cfg-if 1.0.0",
- "dirs",
+ "dirs-next",
  "fs2",
  "libc",
  "log",
@@ -3249,8 +3197,8 @@ version = "0.4.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "db9dfbf470021de34cfaf6983067f460ea19164934a7c2d4b92eec0968eb95f1"
 dependencies = [
- "quote 1.0.7",
- "syn 1.0.53",
+ "quote 1.0.8",
+ "syn 1.0.60",
 ]
 
 [[package]]
@@ -3297,18 +3245,18 @@ checksum = "388a1df253eca08550bef6c72392cfe7c30914bf41df5269b68cbd6ff8f570a3"
 
 [[package]]
 name = "serde"
-version = "1.0.117"
+version = "1.0.123"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b88fa983de7720629c9387e9f517353ed404164b1e482c970a90c1a4aaf7dc1a"
+checksum = "92d5161132722baa40d802cc70b15262b98258453e85e5d1d365c757c73869ae"
 dependencies = [
  "serde_derive",
 ]
 
 [[package]]
 name = "serde-xml-rs"
-version = "0.4.0"
+version = "0.4.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "efe415925cf3d0bbb2fc47d09b56ce03eef51c5d56846468a39bcc293c7a846c"
+checksum = "f0bf1ba0696ccf0872866277143ff1fd14d22eec235d2b23702f95e6660f7dfa"
 dependencies = [
  "log",
  "serde",
@@ -3328,20 +3276,20 @@ dependencies = [
 
 [[package]]
 name = "serde_derive"
-version = "1.0.117"
+version = "1.0.123"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "cbd1ae72adb44aab48f325a02444a5fc079349a8d804c1fc922aed3f7454c74e"
+checksum = "9391c295d64fc0abb2c556bad848f33cb8296276b1ad2677d1ae1ace4f258f31"
 dependencies = [
  "proc-macro2 1.0.24",
- "quote 1.0.7",
- "syn 1.0.53",
+ "quote 1.0.8",
+ "syn 1.0.60",
 ]
 
 [[package]]
 name = "serde_json"
-version = "1.0.60"
+version = "1.0.62"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1500e84d27fe482ed1dc791a56eddc2f230046a040fa908c08bda1d9fb615779"
+checksum = "ea1c6153794552ea7cf7cf63b1231a25de00ec90db326ba6264440fa08e31486"
 dependencies = [
  "itoa",
  "ryu",
@@ -3366,8 +3314,8 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "b2acd6defeddb41eb60bb468f8825d0cfd0c2a76bc03bfd235b6a1dc4f6a1ad5"
 dependencies = [
  "proc-macro2 1.0.24",
- "quote 1.0.7",
- "syn 1.0.53",
+ "quote 1.0.8",
+ "syn 1.0.60",
 ]
 
 [[package]]
@@ -3384,9 +3332,9 @@ dependencies = [
 
 [[package]]
 name = "signal-hook-registry"
-version = "1.2.2"
+version = "1.3.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ce32ea0c6c56d5eacaeb814fbed9960547021d3edd010ded1425f180536b20ab"
+checksum = "16f1d0fef1604ba8f7a073c7e701f213e056707210e9020af4528e0101ce11a6"
 dependencies = [
  "libc",
 ]
@@ -3409,9 +3357,9 @@ checksum = "c111b5bd5695e56cffe5129854aa230b39c93a305372fdbb2668ca2394eea9f8"
 
 [[package]]
 name = "smallvec"
-version = "1.5.0"
+version = "1.6.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7acad6f34eb9e8a259d3283d1e8c1d34d7415943d4895f65cc73813c7396fc85"
+checksum = "fe0f37c9e8f3c5a4a66ad655a93c74daac4ad00c441533bf5c6e7990bb42604e"
 
 [[package]]
 name = "smithay-client-toolkit"
@@ -3448,9 +3396,9 @@ dependencies = [
 
 [[package]]
 name = "smithay-clipboard"
-version = "0.6.2"
+version = "0.6.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ab88b219728cad0697a6c9e75da50bf5220ba01b3485e33e407931539a8ebc91"
+checksum = "06384dfaf645908220d976ae24ed39f6cf92efecb0225ea0a948e403014de527"
 dependencies = [
  "smithay-client-toolkit 0.12.2",
  "wayland-client 0.28.3",
@@ -3474,27 +3422,26 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "1508efa03c362e23817f96cde18abed596a25219a8b2c66e8db33c03543d315b"
 dependencies = [
  "proc-macro2 1.0.24",
- "quote 1.0.7",
- "syn 1.0.53",
+ "quote 1.0.8",
+ "syn 1.0.60",
 ]
 
 [[package]]
 name = "socket2"
-version = "0.3.17"
+version = "0.3.19"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2c29947abdee2a218277abeca306f25789c938e500ea5a9d4b12a5a504466902"
+checksum = "122e570113d28d773067fab24266b66753f6ea915758651696b6e35e49f88d6e"
 dependencies = [
  "cfg-if 1.0.0",
  "libc",
- "redox_syscall",
  "winapi 0.3.9",
 ]
 
 [[package]]
 name = "spirv_cross"
-version = "0.22.1"
+version = "0.22.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ea964c42ce40326fe96111918abe71fa45076da1ea85769f3f1ab1cda9a1d496"
+checksum = "0ebd49af36be83ecd6290b57147e2a0e26145b832634b17146d934b197ca3713"
 dependencies = [
  "cc",
  "js-sys",
@@ -3563,24 +3510,24 @@ dependencies = [
 
 [[package]]
 name = "syn"
-version = "1.0.53"
+version = "1.0.60"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8833e20724c24de12bbaba5ad230ea61c3eafb05b881c7c9d3cfe8638b187e68"
+checksum = "c700597eca8a5a762beb35753ef6b94df201c81cca676604f547495a0d7f0081"
 dependencies = [
  "proc-macro2 1.0.24",
- "quote 1.0.7",
+ "quote 1.0.8",
  "unicode-xid 0.2.1",
 ]
 
 [[package]]
 name = "syn-mid"
-version = "0.5.1"
+version = "0.5.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c42823f0ff906a3eb8109610e825221b07fb1456d45c7d01cf18cb581b23ecfb"
+checksum = "baa8e7560a164edb1621a55d18a0c59abf49d360f47aa7b821061dd7eea7fac9"
 dependencies = [
  "proc-macro2 1.0.24",
- "quote 1.0.7",
- "syn 1.0.53",
+ "quote 1.0.8",
+ "syn 1.0.60",
 ]
 
 [[package]]
@@ -3590,8 +3537,8 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "b834f2d66f734cb897113e34aaff2f1ab4719ca946f9a7358dba8f8064148701"
 dependencies = [
  "proc-macro2 1.0.24",
- "quote 1.0.7",
- "syn 1.0.53",
+ "quote 1.0.8",
+ "syn 1.0.60",
  "unicode-xid 0.2.1",
 ]
 
@@ -3603,14 +3550,14 @@ checksum = "ab0e7238dcc7b40a7be719a25365910f6807bd864f4cce6b2e6b873658e2b19d"
 
 [[package]]
 name = "tempfile"
-version = "3.1.0"
+version = "3.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7a6e24d9338a0a5be79593e2fa15a648add6138caa803e2d5bc782c371732ca9"
+checksum = "dac1c663cfc93810f88aed9b8941d48cabf856a1b111c29a40439018d870eb22"
 dependencies = [
- "cfg-if 0.1.10",
+ "cfg-if 1.0.0",
  "libc",
- "rand 0.7.3",
- "redox_syscall",
+ "rand 0.8.3",
+ "redox_syscall 0.2.4",
  "remove_dir_all",
  "winapi 0.3.9",
 ]
@@ -3635,22 +3582,22 @@ dependencies = [
 
 [[package]]
 name = "thiserror"
-version = "1.0.22"
+version = "1.0.23"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0e9ae34b84616eedaaf1e9dd6026dbe00dcafa92aa0c8077cb69df1fcfe5e53e"
+checksum = "76cc616c6abf8c8928e2fdcc0dbfab37175edd8fb49a4641066ad1364fdab146"
 dependencies = [
  "thiserror-impl",
 ]
 
 [[package]]
 name = "thiserror-impl"
-version = "1.0.22"
+version = "1.0.23"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9ba20f23e85b10754cd195504aebf6a27e2e6cbe28c17778a0c930724628dd56"
+checksum = "9be73a2caec27583d0046ef3796c3794f868a5bc813db689eed00c7631275cd1"
 dependencies = [
  "proc-macro2 1.0.24",
- "quote 1.0.7",
- "syn 1.0.53",
+ "quote 1.0.8",
+ "syn 1.0.60",
 ]
 
 [[package]]
@@ -3660,17 +3607,17 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "c7fbf4c9d56b320106cd64fd024dadfa0be7cb4706725fc44a7d7ce952d820c1"
 dependencies = [
  "libc",
- "redox_syscall",
+ "redox_syscall 0.1.57",
  "winapi 0.3.9",
 ]
 
 [[package]]
 name = "thread_local"
-version = "1.0.1"
+version = "1.1.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d40c6d1b69745a6ec6fb1ca717914848da4b44ae29d9b3080cbee91d72a69b14"
+checksum = "8018d24e04c95ac8790716a5987d0fec4f8b27249ffa0f7d33f1369bdfb88cbd"
 dependencies = [
- "lazy_static",
+ "once_cell",
 ]
 
 [[package]]
@@ -3681,9 +3628,9 @@ checksum = "7572415bd688d401c52f6e36f4c8e805b9ae1622619303b9fa835d531db0acae"
 
 [[package]]
 name = "tinytemplate"
-version = "1.1.0"
+version = "1.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6d3dc76004a03cec1c5932bca4cdc2e39aaa798e3f82363dd94f9adf6098c12f"
+checksum = "a2ada8616fad06a2d0c455adc530de4ef57605a8120cc65da9653e0e9623ca74"
 dependencies = [
  "serde",
  "serde_json",
@@ -3691,9 +3638,9 @@ dependencies = [
 
 [[package]]
 name = "tokio"
-version = "0.2.23"
+version = "0.2.25"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a6d7ad61edd59bfcc7e80dababf0f4aed2e6d5e0ba1659356ae889752dfc12ff"
+checksum = "6703a273949a90131b290be1fe7b039d0fc884aa1935860dfcbe056f28cd8092"
 dependencies = [
  "bytes",
  "fnv",
@@ -3712,21 +3659,21 @@ dependencies = [
 
 [[package]]
 name = "toml"
-version = "0.5.7"
+version = "0.5.8"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "75cf45bb0bef80604d001caaec0d09da99611b3c0fd39d3080468875cdb65645"
+checksum = "a31142970826733df8241ef35dc040ef98c679ab14d7c3e54d827099b3acecaa"
 dependencies = [
  "serde",
 ]
 
 [[package]]
 name = "tracing"
-version = "0.1.22"
+version = "0.1.23"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9f47026cdc4080c07e49b37087de021820269d996f581aac150ef9e5583eefe3"
+checksum = "f7d40a22fd029e33300d8d89a5cc8ffce18bb7c587662f54629e94c9de5487f3"
 dependencies = [
  "cfg-if 1.0.0",
- "pin-project-lite 0.2.0",
+ "pin-project-lite 0.2.4",
  "tracing-core",
 ]
 
@@ -3741,9 +3688,9 @@ dependencies = [
 
 [[package]]
 name = "ttf-parser"
-version = "0.8.3"
+version = "0.11.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7622061403fd00f0820df288e5a580e87d3ce15a1c4313c59fd1ffb77129903f"
+checksum = "f3e7994fc4aed0ee366a4b0d01562c8a7cd5a5017088bceb6921b0c8c538f34e"
 
 [[package]]
 name = "twox-hash"
@@ -3897,15 +3844,15 @@ checksum = "cccddf32554fecc6acb585f82a32a72e28b48f8c4c1883ddfeeeaa96f7d8e519"
 
 [[package]]
 name = "wasi"
-version = "0.10.1+wasi-snapshot-preview1"
+version = "0.10.2+wasi-snapshot-preview1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "93c6c3420963c5c64bca373b25e77acb562081b9bb4dd5bb864187742186cea9"
+checksum = "fd6fbd9a79829dd1ad0cc20627bf1ed606756a7f77edff7b66b7064f9cb327c6"
 
 [[package]]
 name = "wasm-bindgen"
-version = "0.2.69"
+version = "0.2.70"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3cd364751395ca0f68cafb17666eee36b63077fb5ecd972bbcd74c90c4bf736e"
+checksum = "55c0f7123de74f0dab9b7d00fd614e7b19349cd1e2f5252bbe9b1754b59433be"
 dependencies = [
  "cfg-if 1.0.0",
  "wasm-bindgen-macro",
@@ -3913,24 +3860,24 @@ dependencies = [
 
 [[package]]
 name = "wasm-bindgen-backend"
-version = "0.2.69"
+version = "0.2.70"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1114f89ab1f4106e5b55e688b828c0ab0ea593a1ea7c094b141b14cbaaec2d62"
+checksum = "7bc45447f0d4573f3d65720f636bbcc3dd6ce920ed704670118650bcd47764c7"
 dependencies = [
  "bumpalo",
  "lazy_static",
  "log",
  "proc-macro2 1.0.24",
- "quote 1.0.7",
- "syn 1.0.53",
+ "quote 1.0.8",
+ "syn 1.0.60",
  "wasm-bindgen-shared",
 ]
 
 [[package]]
 name = "wasm-bindgen-futures"
-version = "0.4.19"
+version = "0.4.20"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1fe9756085a84584ee9457a002b7cdfe0bfff169f45d2591d8be1345a6780e35"
+checksum = "3de431a2910c86679c34283a33f66f4e4abd7e0aec27b6669060148872aadf94"
 dependencies = [
  "cfg-if 1.0.0",
  "js-sys",
@@ -3940,32 +3887,32 @@ dependencies = [
 
 [[package]]
 name = "wasm-bindgen-macro"
-version = "0.2.69"
+version = "0.2.70"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7a6ac8995ead1f084a8dea1e65f194d0973800c7f571f6edd70adf06ecf77084"
+checksum = "3b8853882eef39593ad4174dd26fc9865a64e84026d223f63bb2c42affcbba2c"
 dependencies = [
- "quote 1.0.7",
+ "quote 1.0.8",
  "wasm-bindgen-macro-support",
 ]
 
 [[package]]
 name = "wasm-bindgen-macro-support"
-version = "0.2.69"
+version = "0.2.70"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b5a48c72f299d80557c7c62e37e7225369ecc0c963964059509fbafe917c7549"
+checksum = "4133b5e7f2a531fa413b3a1695e925038a05a71cf67e87dafa295cb645a01385"
 dependencies = [
  "proc-macro2 1.0.24",
- "quote 1.0.7",
- "syn 1.0.53",
+ "quote 1.0.8",
+ "syn 1.0.60",
  "wasm-bindgen-backend",
  "wasm-bindgen-shared",
 ]
 
 [[package]]
 name = "wasm-bindgen-shared"
-version = "0.2.69"
+version = "0.2.70"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7e7811dd7f9398f14cc76efd356f98f03aa30419dea46aa810d71e819fc97158"
+checksum = "dd4945e4943ae02d15c13962b38a5b1e81eadd4b71214eee75af64a4d6a4fd64"
 
 [[package]]
 name = "wasmparser"
@@ -4081,7 +4028,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "7010ba5767b3fcd350decc59055390b4ebe6bd1b9279a9feb1f1888987f1133d"
 dependencies = [
  "proc-macro2 1.0.24",
- "quote 1.0.7",
+ "quote 1.0.8",
  "xml-rs",
 ]
 
@@ -4108,9 +4055,9 @@ dependencies = [
 
 [[package]]
 name = "web-sys"
-version = "0.3.46"
+version = "0.3.47"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "222b1ef9334f92a21d3fb53dc3fd80f30836959a90f9274a626d7e06315ba3c3"
+checksum = "c40dc691fc48003eba817c38da7113c15698142da971298003cac3ef175680b3"
 dependencies = [
  "js-sys",
  "wasm-bindgen",
@@ -4374,6 +4321,6 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "d498dbd1fd7beb83c86709ae1c33ca50942889473473d287d56ce4770a18edfb"
 dependencies = [
  "proc-macro2 1.0.24",
- "syn 1.0.53",
+ "syn 1.0.60",
  "synstructure",
 ]
diff --git a/Cargo.toml b/Cargo.toml
index 2d986f0009..9c25dd9e56 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -8,7 +8,6 @@ members = [
     "compiler/can",
     "compiler/problem",
     "compiler/types",
-    "compiler/uniq",
     "compiler/builtins",
     "compiler/constrain",
     "compiler/unify",
diff --git a/cli/Cargo.toml b/cli/Cargo.toml
index e0bb9f0a1c..b420d22a37 100644
--- a/cli/Cargo.toml
+++ b/cli/Cargo.toml
@@ -40,7 +40,6 @@ roc_problem = { path = "../compiler/problem" }
 roc_types = { path = "../compiler/types" }
 roc_builtins = { path = "../compiler/builtins" }
 roc_constrain = { path = "../compiler/constrain" }
-roc_uniq = { path = "../compiler/uniq" }
 roc_unify = { path = "../compiler/unify" }
 roc_solve = { path = "../compiler/solve" }
 roc_mono = { path = "../compiler/mono" }
diff --git a/compiler/build/Cargo.toml b/compiler/build/Cargo.toml
index 4b48dd2d26..99e10bf0f1 100644
--- a/compiler/build/Cargo.toml
+++ b/compiler/build/Cargo.toml
@@ -15,7 +15,6 @@ roc_problem = { path = "../problem" }
 roc_types = { path = "../types" }
 roc_builtins = { path = "../builtins" }
 roc_constrain = { path = "../constrain" }
-roc_uniq = { path = "../uniq" }
 roc_unify = { path = "../unify" }
 roc_solve = { path = "../solve" }
 roc_mono = { path = "../mono" }
diff --git a/compiler/can/tests/helpers/mod.rs b/compiler/can/tests/helpers/mod.rs
index 402866e85c..3d7c7e0b2c 100644
--- a/compiler/can/tests/helpers/mod.rs
+++ b/compiler/can/tests/helpers/mod.rs
@@ -10,7 +10,7 @@ use roc_collections::all::MutMap;
 use roc_module::symbol::{IdentIds, Interns, ModuleId, ModuleIds};
 use roc_parse::ast::{self, Attempting};
 use roc_parse::blankspace::space0_before;
-use roc_parse::parser::{loc, Bag, Parser, State};
+use roc_parse::parser::{loc, Bag, Parser, State, SyntaxError};
 use roc_problem::can::Problem;
 use roc_region::all::{Located, Region};
 use roc_types::subs::{VarStore, Variable};
@@ -21,7 +21,10 @@ pub fn test_home() -> ModuleId {
 }
 
 #[allow(dead_code)]
-pub fn parse_with<'a>(arena: &'a Bump, input: &'a str) -> Result<ast::Expr<'a>, Bag<'a>> {
+pub fn parse_with<'a>(
+    arena: &'a Bump,
+    input: &'a str,
+) -> Result<ast::Expr<'a>, Bag<'a, SyntaxError<'a>>> {
     parse_loc_with(arena, input).map(|loc_expr| loc_expr.value)
 }
 
@@ -29,7 +32,7 @@ pub fn parse_with<'a>(arena: &'a Bump, input: &'a str) -> Result<ast::Expr<'a>,
 pub fn parse_loc_with<'a>(
     arena: &'a Bump,
     input: &'a str,
-) -> Result<Located<ast::Expr<'a>>, Bag<'a>> {
+) -> Result<Located<ast::Expr<'a>>, Bag<'a, SyntaxError<'a>>> {
     let state = State::new_in(arena, input.trim().as_bytes(), Attempting::Module);
     let parser = space0_before(loc(roc_parse::expr::expr(0)), 0);
     let answer = parser.parse(&arena, state);
diff --git a/compiler/constrain/Cargo.toml b/compiler/constrain/Cargo.toml
index feb907ca3d..b703ad9164 100644
--- a/compiler/constrain/Cargo.toml
+++ b/compiler/constrain/Cargo.toml
@@ -13,7 +13,6 @@ roc_parse = { path = "../parse" }
 roc_types = { path = "../types" }
 roc_can = { path = "../can" }
 roc_builtins = { path = "../builtins" }
-roc_uniq = { path = "../uniq" }
 
 [dev-dependencies]
 pretty_assertions = "0.5.1"
diff --git a/compiler/constrain/src/lib.rs b/compiler/constrain/src/lib.rs
index 0e30c75a9c..2304b8a738 100644
--- a/compiler/constrain/src/lib.rs
+++ b/compiler/constrain/src/lib.rs
@@ -5,4 +5,3 @@ pub mod builtins;
 pub mod expr;
 pub mod module;
 pub mod pattern;
-pub mod uniq;
diff --git a/compiler/constrain/src/module.rs b/compiler/constrain/src/module.rs
index afdf6bdd39..57cd74df17 100644
--- a/compiler/constrain/src/module.rs
+++ b/compiler/constrain/src/module.rs
@@ -26,7 +26,8 @@ pub fn constrain_module(
     module: &ModuleOutput,
     home: ModuleId,
     mode: Mode,
-    var_store: &mut VarStore,
+    // TODO remove parameter
+    _var_store: &mut VarStore,
 ) -> Constraint {
     use Mode::*;
 
@@ -40,7 +41,7 @@ pub fn constrain_module(
 
     match mode {
         Standard => constrain_decls(home, decls),
-        Uniqueness => crate::uniq::constrain_decls(home, decls, var_store),
+        Uniqueness => constrain_decls(home, decls),
     }
 }
 
diff --git a/compiler/constrain/src/uniq.rs b/compiler/constrain/src/uniq.rs
deleted file mode 100644
index 4d6552ea83..0000000000
--- a/compiler/constrain/src/uniq.rs
+++ /dev/null
@@ -1,2641 +0,0 @@
-use crate::builtins::{num_floatingpoint, num_integer, num_num};
-use crate::expr::{exists, Info};
-use roc_can::annotation::IntroducedVariables;
-use roc_can::constraint::Constraint::{self, *};
-use roc_can::constraint::LetConstraint;
-use roc_can::def::{Declaration, Def};
-use roc_can::expected::{Expected, PExpected};
-use roc_can::expr::{Expr, Field, WhenBranch};
-use roc_can::pattern::{DestructType, Pattern, RecordDestruct};
-use roc_collections::all::{ImMap, ImSet, Index, SendMap};
-use roc_module::ident::{Ident, Lowercase};
-use roc_module::symbol::{ModuleId, Symbol};
-use roc_region::all::{Located, Region};
-use roc_types::boolean_algebra::Bool;
-use roc_types::subs::{VarStore, Variable};
-use roc_types::types::AnnotationSource::{self, *};
-use roc_types::types::Type::{self, *};
-use roc_types::types::{Category, PReason, Reason, RecordField};
-use roc_uniq::builtins::{attr_type, empty_list_type, list_type, str_type};
-use roc_uniq::sharing::{self, FieldAccess, Mark, Usage, VarUsage};
-
-pub struct Env {
-    /// Whenever we encounter a user-defined type variable (a "rigid" var for short),
-    /// for example `u` and `a` in the annotation `identity : Attr u a -> Attr u a`, we add it to this
-    /// map so that expressions within that annotation can share these vars.
-    pub rigids: ImMap<Lowercase, (Variable, Variable)>,
-    pub home: ModuleId,
-}
-
-pub fn constrain_declaration(
-    home: ModuleId,
-    var_store: &mut VarStore,
-    region: Region,
-    loc_expr: &Located<Expr>,
-    _declared_idents: &ImMap<Ident, (Symbol, Region)>,
-    expected: Expected<Type>,
-) -> Constraint {
-    // TODO this means usage is local to individual declarations.
-    // Should be per-module in the future!
-    let mut var_usage = VarUsage::default();
-
-    sharing::annotate_usage(&loc_expr.value, &mut var_usage);
-
-    let mut applied_usage_constraint = ImSet::default();
-    constrain_expr(
-        &Env {
-            rigids: ImMap::default(),
-            home,
-        },
-        var_store,
-        &var_usage,
-        &mut applied_usage_constraint,
-        region,
-        &loc_expr.value,
-        expected,
-    )
-}
-
-/// Constrain top-level module declarations
-#[inline(always)]
-pub fn constrain_decls(
-    home: ModuleId,
-    decls: &[Declaration],
-    var_store: &mut VarStore,
-) -> Constraint {
-    let mut constraint = Constraint::SaveTheEnvironment;
-
-    // perform usage analysis on the whole file
-    let mut var_usage = VarUsage::default();
-
-    for decl in decls.iter().rev() {
-        // NOTE: rigids are empty because they are not shared between top-level definitions
-        match decl {
-            Declaration::Declare(def) | Declaration::Builtin(def) => {
-                sharing::annotate_usage(&def.loc_expr.value, &mut var_usage);
-            }
-            Declaration::DeclareRec(defs) => {
-                for def in defs {
-                    sharing::annotate_usage(&def.loc_expr.value, &mut var_usage);
-                }
-            }
-            Declaration::InvalidCycle(_, _) => {
-                // any usage of a value defined in an invalid cycle will blow up
-                // so for the analysis usage by such values doesn't count
-                continue;
-            }
-        }
-    }
-
-    let mut env = Env {
-        home,
-        rigids: ImMap::default(),
-    };
-
-    for decl in decls.iter().rev() {
-        // clear the set of rigids from the previous iteration.
-        // rigids are not shared between top-level definitions.
-        env.rigids.clear();
-
-        match decl {
-            Declaration::Declare(def) | Declaration::Builtin(def) => {
-                constraint = exists(
-                    Vec::new(),
-                    constrain_def(
-                        &env,
-                        var_store,
-                        &var_usage,
-                        &mut ImSet::default(),
-                        def,
-                        constraint,
-                    ),
-                );
-            }
-            Declaration::DeclareRec(defs) => {
-                constraint = exists(
-                    Vec::new(),
-                    constrain_recursive_defs(
-                        &env,
-                        var_store,
-                        &var_usage,
-                        &mut ImSet::default(),
-                        defs,
-                        constraint,
-                    ),
-                );
-            }
-            Declaration::InvalidCycle(_, _) => {
-                // invalid cycles give a canonicalization error. we skip them here.
-                continue;
-            }
-        }
-    }
-
-    constraint
-}
-
-pub struct PatternState {
-    pub headers: SendMap<Symbol, Located<Type>>,
-    pub vars: Vec<Variable>,
-    pub constraints: Vec<Constraint>,
-}
-
-fn constrain_pattern(
-    env: &Env,
-    var_store: &mut VarStore,
-    var_usage: &VarUsage,
-    applied_usage_constraint: &mut ImSet<Symbol>,
-    state: &mut PatternState,
-    pattern: &Located<Pattern>,
-    expected: PExpected<Type>,
-) {
-    use roc_can::pattern::Pattern::*;
-    use roc_types::types::PatternCategory;
-
-    let region = pattern.region;
-
-    match &pattern.value {
-        Identifier(symbol) => {
-            state.headers.insert(
-                *symbol,
-                Located {
-                    region: pattern.region,
-                    value: expected.get_type(),
-                },
-            );
-        }
-
-        NumLiteral(inner_var, _) => {
-            let (inner_uvar, num_var, num_type) = unique_unbound_num(*inner_var, var_store);
-            state.constraints.push(exists(
-                vec![num_var, inner_uvar, *inner_var],
-                Constraint::Pattern(pattern.region, PatternCategory::Num, num_type, expected),
-            ));
-        }
-
-        IntLiteral(inner_var, _) => {
-            let (a, b, c, num_type) = unique_int(var_store);
-
-            state.constraints.push(exists(
-                vec![*inner_var, a, b, c],
-                Constraint::Pattern(pattern.region, PatternCategory::Int, num_type, expected),
-            ));
-        }
-        FloatLiteral(inner_var, _) => {
-            let (a, b, c, num_type) = unique_float(var_store);
-
-            state.constraints.push(exists(
-                vec![*inner_var, a, b, c],
-                Constraint::Pattern(pattern.region, PatternCategory::Float, num_type, expected),
-            ));
-        }
-
-        StrLiteral(_) => {
-            let uniq_var = var_store.fresh();
-            state.constraints.push(exists(
-                vec![uniq_var],
-                Constraint::Pattern(
-                    pattern.region,
-                    PatternCategory::Str,
-                    str_type(Bool::variable(uniq_var)),
-                    expected,
-                ),
-            ));
-        }
-
-        RecordDestructure {
-            whole_var,
-            ext_var,
-            destructs,
-        } => {
-            // TODO if a subpattern doesn't bind any identifiers, it doesn't count for uniqueness
-            let mut pattern_uniq_vars = Vec::with_capacity(destructs.len());
-
-            state.vars.push(*whole_var);
-            state.vars.push(*ext_var);
-            let ext_type = Type::Variable(*ext_var);
-
-            let mut field_types: SendMap<Lowercase, RecordField<Type>> = SendMap::default();
-            for Located {
-                value:
-                    RecordDestruct {
-                        var,
-                        label,
-                        symbol,
-                        typ,
-                    },
-                ..
-            } in destructs
-            {
-                let pat_uniq_var = var_store.fresh();
-                pattern_uniq_vars.push(pat_uniq_var);
-
-                let pat_type = attr_type(Bool::variable(pat_uniq_var), Type::Variable(*var));
-                let expected = PExpected::NoExpectation(pat_type.clone());
-
-                if !state.headers.contains_key(&symbol) {
-                    state
-                        .headers
-                        .insert(*symbol, Located::at(pattern.region, pat_type.clone()));
-                }
-
-                let field_type = match typ {
-                    DestructType::Guard(guard_var, loc_guard) => {
-                        state.constraints.push(Constraint::Pattern(
-                            pattern.region,
-                            PatternCategory::PatternGuard,
-                            Type::Variable(*guard_var),
-                            PExpected::NoExpectation(pat_type.clone()),
-                        ));
-                        state.vars.push(*guard_var);
-                        constrain_pattern(
-                            env,
-                            var_store,
-                            var_usage,
-                            applied_usage_constraint,
-                            state,
-                            loc_guard,
-                            expected,
-                        );
-
-                        RecordField::Demanded(pat_type)
-                    }
-                    DestructType::Optional(expr_var, loc_expr) => {
-                        let expr_expected = Expected::ForReason(
-                            Reason::RecordDefaultField(label.clone()),
-                            pat_type.clone(),
-                            loc_expr.region,
-                        );
-
-                        state.constraints.push(Constraint::Pattern(
-                            region,
-                            PatternCategory::PatternDefault,
-                            Type::Variable(*expr_var),
-                            PExpected::ForReason(
-                                PReason::OptionalField,
-                                pat_type.clone(),
-                                loc_expr.region,
-                            ),
-                        ));
-
-                        state.vars.push(*expr_var);
-
-                        let expr_con = constrain_expr(
-                            env,
-                            var_store,
-                            var_usage,
-                            applied_usage_constraint,
-                            loc_expr.region,
-                            &loc_expr.value,
-                            expr_expected,
-                        );
-                        state.constraints.push(expr_con);
-
-                        RecordField::Optional(pat_type)
-                    }
-                    DestructType::Required => {
-                        // No extra constraints necessary.
-                        RecordField::Demanded(pat_type)
-                    }
-                };
-
-                field_types.insert(label.clone(), field_type);
-
-                state.vars.push(*var);
-            }
-
-            let record_uniq_type = {
-                let empty_var = var_store.fresh();
-                state.vars.push(empty_var);
-                state.vars.extend(pattern_uniq_vars.clone());
-                Bool::container(empty_var, pattern_uniq_vars)
-            };
-
-            let record_type = attr_type(
-                record_uniq_type,
-                Type::Record(field_types, Box::new(ext_type)),
-            );
-
-            let whole_con = Constraint::Eq(
-                Type::Variable(*whole_var),
-                Expected::NoExpectation(record_type),
-                Category::Storage(std::file!(), std::line!()),
-                region,
-            );
-
-            let record_con = Constraint::Pattern(
-                region,
-                PatternCategory::Record,
-                Type::Variable(*whole_var),
-                expected,
-            );
-
-            state.constraints.push(whole_con);
-            state.constraints.push(record_con);
-        }
-
-        AppliedTag {
-            whole_var,
-            ext_var,
-            tag_name,
-            arguments,
-        } => {
-            // TODO if a subpattern doesn't bind any identifiers, it doesn't count for uniqueness
-            let mut argument_types = Vec::with_capacity(arguments.len());
-            let mut pattern_uniq_vars = Vec::with_capacity(arguments.len());
-
-            for (pattern_var, loc_pattern) in arguments {
-                state.vars.push(*pattern_var);
-
-                let pat_uniq_var = var_store.fresh();
-                pattern_uniq_vars.push(pat_uniq_var);
-
-                let pattern_type =
-                    attr_type(Bool::variable(pat_uniq_var), Type::Variable(*pattern_var));
-                argument_types.push(pattern_type.clone());
-
-                let expected = PExpected::NoExpectation(pattern_type);
-                constrain_pattern(
-                    env,
-                    var_store,
-                    var_usage,
-                    applied_usage_constraint,
-                    state,
-                    loc_pattern,
-                    expected,
-                );
-            }
-
-            let tag_union_uniq_type = {
-                let empty_var = var_store.fresh();
-                state.vars.push(empty_var);
-                state.vars.extend(pattern_uniq_vars.clone());
-                Bool::container(empty_var, pattern_uniq_vars)
-            };
-            let union_type = attr_type(
-                tag_union_uniq_type,
-                Type::TagUnion(
-                    vec![(tag_name.clone(), argument_types)],
-                    Box::new(Type::Variable(*ext_var)),
-                ),
-            );
-
-            let whole_con = Constraint::Eq(
-                Type::Variable(*whole_var),
-                Expected::NoExpectation(union_type),
-                Category::Storage(std::file!(), std::line!()),
-                region,
-            );
-
-            let tag_con = Constraint::Pattern(
-                region,
-                PatternCategory::Ctor(tag_name.clone()),
-                Type::Variable(*whole_var),
-                expected,
-            );
-
-            state.vars.push(*whole_var);
-            state.vars.push(*ext_var);
-
-            state.constraints.push(whole_con);
-            state.constraints.push(tag_con);
-        }
-
-        Underscore | Shadowed(_, _) | MalformedPattern(_, _) | UnsupportedPattern(_) => {
-            // no constraints
-        }
-    }
-}
-
-fn unique_unbound_num(inner_var: Variable, var_store: &mut VarStore) -> (Variable, Variable, Type) {
-    let num_uvar = var_store.fresh();
-    let inner_uvar = var_store.fresh();
-
-    let val_type = Type::Variable(inner_var);
-    let val_utype = attr_type(Bool::variable(inner_uvar), val_type);
-
-    let num_utype = num_num(val_utype);
-    let num_type = attr_type(Bool::variable(num_uvar), num_utype);
-
-    (inner_uvar, num_uvar, num_type)
-}
-
-fn unique_int(var_store: &mut VarStore) -> (Variable, Variable, Variable, Type) {
-    let num_uvar1 = var_store.fresh();
-    let num_uvar2 = var_store.fresh();
-    let num_uvar3 = var_store.fresh();
-    let num_uvar4 = var_store.fresh();
-
-    let integer = num_integer(Type::Variable(num_uvar4));
-    let attr_int = attr_type(Bool::variable(num_uvar2), integer);
-    let num = num_num(attr_int);
-    let attr_num = attr_type(Bool::variable(num_uvar3), num);
-
-    (num_uvar1, num_uvar2, num_uvar3, attr_num)
-}
-
-fn unique_float(var_store: &mut VarStore) -> (Variable, Variable, Variable, Type) {
-    let num_uvar1 = var_store.fresh();
-    let num_uvar2 = var_store.fresh();
-    let num_uvar3 = var_store.fresh();
-    let num_uvar4 = var_store.fresh();
-
-    let fp = num_floatingpoint(Type::Variable(num_uvar4));
-    let attr_fp = attr_type(Bool::variable(num_uvar2), fp);
-    let num = num_num(attr_fp);
-    let attr_num = attr_type(Bool::variable(num_uvar3), num);
-
-    (num_uvar1, num_uvar2, num_uvar3, attr_num)
-}
-
-pub fn constrain_expr(
-    env: &Env,
-    var_store: &mut VarStore,
-    var_usage: &VarUsage,
-    applied_usage_constraint: &mut ImSet<Symbol>,
-    region: Region,
-    expr: &Expr,
-    expected: Expected<Type>,
-) -> Constraint {
-    pub use roc_can::expr::Expr::*;
-
-    match expr {
-        Num(inner_var, _) => {
-            let var = var_store.fresh();
-            let (inner_uvar, num_var, num_type) = unique_unbound_num(*inner_var, var_store);
-
-            exists(
-                vec![var, *inner_var, inner_uvar, num_var],
-                And(vec![
-                    Eq(
-                        Type::Variable(var),
-                        Expected::ForReason(Reason::NumLiteral, num_type, region),
-                        Category::Num,
-                        region,
-                    ),
-                    Eq(Type::Variable(var), expected, Category::Num, region),
-                ]),
-            )
-        }
-        Int(var, _, _) => {
-            let (a, b, c, num_type) = unique_int(var_store);
-
-            exists(
-                vec![*var, a, b, c],
-                And(vec![
-                    Eq(
-                        Type::Variable(*var),
-                        Expected::ForReason(Reason::IntLiteral, num_type, region),
-                        Category::Int,
-                        region,
-                    ),
-                    Eq(Type::Variable(*var), expected, Category::Int, region),
-                ]),
-            )
-        }
-        Float(var, _, _) => {
-            let (a, b, c, num_type) = unique_float(var_store);
-
-            exists(
-                vec![*var, a, b, c],
-                And(vec![
-                    Eq(
-                        Type::Variable(*var),
-                        Expected::ForReason(Reason::FloatLiteral, num_type, region),
-                        Category::Float,
-                        region,
-                    ),
-                    Eq(Type::Variable(*var), expected, Category::Float, region),
-                ]),
-            )
-        }
-        Str(_) => {
-            let uniq_type = var_store.fresh();
-            let inferred = str_type(Bool::variable(uniq_type));
-
-            exists(
-                vec![uniq_type],
-                Eq(inferred, expected, Category::Str, region),
-            )
-        }
-        EmptyRecord => {
-            let uniq_type = var_store.fresh();
-
-            exists(
-                vec![uniq_type],
-                Eq(
-                    attr_type(Bool::variable(uniq_type), EmptyRec),
-                    expected,
-                    Category::Record,
-                    region,
-                ),
-            )
-        }
-        Record {
-            record_var, fields, ..
-        } => {
-            // NOTE: canonicalization guarantees at least one field
-            // zero fields generates an EmptyRecord
-            let mut field_types = SendMap::default();
-            let mut field_vars = Vec::with_capacity(fields.len());
-            field_vars.push(*record_var);
-
-            // Constraints need capacity for each field + 1 for the record itself + 1 for ext
-            let mut constraints = Vec::with_capacity(2 + fields.len());
-
-            for (label, ref field) in fields.iter() {
-                let field_var = var_store.fresh();
-                let field_type = Variable(field_var);
-                let field_expected = Expected::NoExpectation(field_type.clone());
-                let loc_expr = &*field.loc_expr;
-                let field_con = constrain_expr(
-                    env,
-                    var_store,
-                    var_usage,
-                    applied_usage_constraint,
-                    loc_expr.region,
-                    &loc_expr.value,
-                    field_expected,
-                );
-
-                field_vars.push(field_var);
-                field_types.insert(label.clone(), RecordField::Required(field_type));
-
-                constraints.push(field_con);
-            }
-
-            let record_uniq_var = var_store.fresh();
-            field_vars.push(record_uniq_var);
-            let record_type = attr_type(
-                Bool::variable(record_uniq_var),
-                Type::Record(
-                    field_types,
-                    // TODO can we avoid doing Box::new on every single one of these?
-                    // For example, could we have a single lazy_static global Box they
-                    // could all share?
-                    Box::new(Type::EmptyRec),
-                ),
-            );
-            let record_con = Eq(record_type, expected.clone(), Category::Record, region);
-            let ext_con = Eq(
-                Type::Variable(*record_var),
-                expected,
-                Category::Record,
-                region,
-            );
-
-            constraints.push(record_con);
-            constraints.push(ext_con);
-
-            exists(field_vars, And(constraints))
-        }
-        Tag {
-            variant_var,
-            ext_var,
-            name,
-            arguments,
-        } => {
-            let mut vars = Vec::with_capacity(arguments.len());
-            let mut types = Vec::with_capacity(arguments.len());
-            let mut arg_cons = Vec::with_capacity(arguments.len());
-
-            for (var, loc_expr) in arguments {
-                let arg_con = constrain_expr(
-                    env,
-                    var_store,
-                    var_usage,
-                    applied_usage_constraint,
-                    loc_expr.region,
-                    &loc_expr.value,
-                    Expected::NoExpectation(Type::Variable(*var)),
-                );
-
-                arg_cons.push(arg_con);
-                vars.push(*var);
-                types.push(Type::Variable(*var));
-            }
-
-            let uniq_var = var_store.fresh();
-
-            let union_type = attr_type(
-                Bool::variable(uniq_var),
-                Type::TagUnion(
-                    vec![(name.clone(), types)],
-                    Box::new(Type::Variable(*ext_var)),
-                ),
-            );
-
-            let union_con = Eq(
-                union_type,
-                expected.clone(),
-                Category::TagApply {
-                    tag_name: name.clone(),
-                    args_count: arguments.len(),
-                },
-                region,
-            );
-            let ast_con = Eq(
-                Type::Variable(*variant_var),
-                expected,
-                Category::TagApply {
-                    tag_name: name.clone(),
-                    args_count: arguments.len(),
-                },
-                region,
-            );
-
-            vars.push(uniq_var);
-            vars.push(*variant_var);
-            vars.push(*ext_var);
-            arg_cons.push(union_con);
-            arg_cons.push(ast_con);
-
-            exists(vars, And(arg_cons))
-        }
-        List {
-            list_var,
-            elem_var,
-            loc_elems,
-        } => {
-            let uniq_var = var_store.fresh();
-            if loc_elems.is_empty() {
-                let inferred = empty_list_type(Bool::variable(uniq_var), *elem_var);
-                exists(
-                    vec![*elem_var, uniq_var],
-                    Eq(inferred, expected, Category::List, region),
-                )
-            } else {
-                // constrain `expected ~ List a` and that all elements `~ a`.
-                let entry_type = Type::Variable(*elem_var);
-                let mut constraints = Vec::with_capacity(1 + loc_elems.len());
-
-                for (index, loc_elem) in loc_elems.iter().enumerate() {
-                    let elem_expected = Expected::ForReason(
-                        Reason::ElemInList {
-                            index: Index::zero_based(index),
-                        },
-                        entry_type.clone(),
-                        region,
-                    );
-                    let constraint = constrain_expr(
-                        env,
-                        var_store,
-                        var_usage,
-                        applied_usage_constraint,
-                        loc_elem.region,
-                        &loc_elem.value,
-                        elem_expected,
-                    );
-
-                    constraints.push(constraint);
-                }
-
-                let inferred = list_type(Bool::variable(uniq_var), entry_type);
-                constraints.push(Eq(inferred, expected.clone(), Category::List, region));
-
-                let stored = Type::Variable(*list_var);
-                constraints.push(Eq(
-                    stored,
-                    expected,
-                    Category::Storage(std::file!(), std::line!()),
-                    region,
-                ));
-
-                exists(vec![*elem_var, *list_var, uniq_var], And(constraints))
-            }
-        }
-        Var(symbol) => {
-            let usage = var_usage.get_usage(*symbol);
-
-            constrain_var(
-                var_store,
-                applied_usage_constraint,
-                *symbol,
-                usage,
-                region,
-                expected,
-            )
-        }
-        Closure {
-            function_type: fn_var,
-            return_type: ret_var,
-            closure_type: closure_var,
-            closure_ext_var,
-            recursive: recursion,
-            arguments,
-            loc_body: boxed,
-            captured_symbols,
-            name,
-            ..
-        } => {
-            use roc_can::expr::Recursive;
-
-            let loc_body_expr = &**boxed;
-            let mut state = PatternState {
-                headers: SendMap::default(),
-                vars: Vec::with_capacity(arguments.len()),
-                constraints: Vec::with_capacity(1),
-            };
-            let mut vars = Vec::with_capacity(state.vars.capacity() + 1);
-            let mut pattern_types = Vec::with_capacity(state.vars.capacity());
-            let ret_var = *ret_var;
-            let ret_type = Type::Variable(ret_var);
-            let closure_var = *closure_var;
-            let closure_ext_var = *closure_ext_var;
-
-            vars.push(ret_var);
-            vars.push(closure_var);
-            vars.push(closure_ext_var);
-            vars.push(*fn_var);
-
-            for (pattern_var, loc_pattern) in arguments {
-                let pattern_type = Type::Variable(*pattern_var);
-                let pattern_expected = PExpected::NoExpectation(pattern_type.clone());
-
-                pattern_types.push(pattern_type);
-
-                constrain_pattern(
-                    env,
-                    var_store,
-                    var_usage,
-                    applied_usage_constraint,
-                    &mut state,
-                    loc_pattern,
-                    pattern_expected,
-                );
-
-                vars.push(*pattern_var);
-            }
-
-            let fn_uniq_type;
-            if let Recursive::NotRecursive = recursion {
-                let fn_uniq_var = var_store.fresh();
-                vars.push(fn_uniq_var);
-                fn_uniq_type = Bool::variable(fn_uniq_var);
-            } else {
-                // recursive definitions MUST be Shared
-                fn_uniq_type = Bool::shared()
-            }
-
-            let body_type = Expected::NoExpectation(ret_type.clone());
-            let ret_constraint = constrain_expr(
-                env,
-                var_store,
-                var_usage,
-                applied_usage_constraint,
-                loc_body_expr.region,
-                &loc_body_expr.value,
-                body_type,
-            );
-
-            let defs_constraint = And(state.constraints);
-
-            let closure_constraint = constrain_closure_size(
-                *name,
-                region,
-                captured_symbols,
-                closure_var,
-                closure_ext_var,
-                &mut vars,
-            );
-
-            let fn_type = attr_type(
-                fn_uniq_type,
-                Type::Function(
-                    pattern_types,
-                    Box::new(Type::Variable(closure_var)),
-                    Box::new(ret_type),
-                ),
-            );
-
-            exists(
-                vars,
-                And(vec![
-                    Let(Box::new(LetConstraint {
-                        rigid_vars: Vec::new(),
-                        flex_vars: state.vars,
-                        def_types: state.headers,
-                        defs_constraint,
-                        ret_constraint,
-                    })),
-                    // "the closure's type is equal to expected type"
-                    Eq(fn_type.clone(), expected, Category::Lambda, region),
-                    // "fn_var is equal to the closure's type" - fn_var is used in code gen
-                    Eq(
-                        Type::Variable(*fn_var),
-                        Expected::NoExpectation(fn_type),
-                        Category::Lambda,
-                        region,
-                    ),
-                    closure_constraint,
-                ]),
-            )
-        }
-
-        Call(boxed, loc_args, _) => {
-            let (fn_var, fn_expr, closure_var, ret_var) = &**boxed;
-            let fn_type = Variable(*fn_var);
-            let ret_type = Variable(*ret_var);
-            let closure_type = Variable(*closure_var);
-            let fn_expected = Expected::NoExpectation(fn_type.clone());
-            let fn_region = fn_expr.region;
-
-            let opt_symbol = if let Var(symbol) = fn_expr.value {
-                Some(symbol)
-            } else {
-                None
-            };
-
-            let mut vars = Vec::with_capacity(2 + loc_args.len());
-
-            vars.push(*fn_var);
-            vars.push(*ret_var);
-            vars.push(*closure_var);
-
-            // Canonicalize the function expression and its arguments
-            let fn_con = constrain_expr(
-                env,
-                var_store,
-                var_usage,
-                applied_usage_constraint,
-                fn_region,
-                &fn_expr.value,
-                fn_expected,
-            );
-
-            let fn_reason = Reason::FnCall {
-                name: opt_symbol,
-                arity: loc_args.len() as u8,
-            };
-
-            let mut arg_types = Vec::with_capacity(loc_args.len());
-            let mut arg_cons = Vec::with_capacity(loc_args.len());
-
-            for (index, (arg_var, loc_arg)) in loc_args.iter().enumerate() {
-                let region = loc_arg.region;
-                let arg_type = Variable(*arg_var);
-
-                let reason = Reason::FnArg {
-                    name: opt_symbol,
-                    arg_index: Index::zero_based(index),
-                };
-
-                let expected_arg = Expected::ForReason(reason, arg_type.clone(), region);
-                let arg_con = constrain_expr(
-                    env,
-                    var_store,
-                    var_usage,
-                    applied_usage_constraint,
-                    loc_arg.region,
-                    &loc_arg.value,
-                    expected_arg,
-                );
-
-                vars.push(*arg_var);
-                arg_types.push(arg_type);
-                arg_cons.push(arg_con);
-            }
-
-            let expected_uniq_type = var_store.fresh();
-            vars.push(expected_uniq_type);
-            let expected_fn_type = Expected::ForReason(
-                fn_reason,
-                attr_type(
-                    Bool::variable(expected_uniq_type),
-                    Function(
-                        arg_types,
-                        Box::new(closure_type),
-                        Box::new(ret_type.clone()),
-                    ),
-                ),
-                region,
-            );
-
-            exists(
-                vars,
-                And(vec![
-                    fn_con,
-                    Eq(
-                        fn_type,
-                        expected_fn_type,
-                        Category::CallResult(opt_symbol),
-                        fn_region,
-                    ),
-                    And(arg_cons),
-                    Eq(ret_type, expected, Category::CallResult(opt_symbol), region),
-                ]),
-            )
-        }
-        RunLowLevel { op, args, ret_var } => {
-            // This is a modified version of what we do for function calls.
-
-            let ret_type = Variable(*ret_var);
-            let mut vars = Vec::with_capacity(1 + args.len());
-
-            vars.push(*ret_var);
-
-            // Canonicalize the function expression and its arguments
-
-            let mut arg_types = Vec::with_capacity(args.len());
-            let mut arg_cons = Vec::with_capacity(args.len());
-
-            for (index, (arg_var, arg_expr)) in args.iter().enumerate() {
-                let arg_type = Variable(*arg_var);
-
-                let reason = Reason::LowLevelOpArg {
-                    op: *op,
-                    arg_index: Index::zero_based(index),
-                };
-
-                let expected_arg = Expected::ForReason(reason, arg_type.clone(), region);
-                let arg_con = constrain_expr(
-                    env,
-                    var_store,
-                    var_usage,
-                    applied_usage_constraint,
-                    Region::zero(),
-                    arg_expr,
-                    expected_arg,
-                );
-
-                vars.push(*arg_var);
-                arg_types.push(arg_type);
-                arg_cons.push(arg_con);
-            }
-
-            let expected_uniq_type = var_store.fresh();
-            vars.push(expected_uniq_type);
-
-            exists(
-                vars,
-                And(vec![
-                    And(arg_cons),
-                    Eq(ret_type, expected, Category::LowLevelOpResult(*op), region),
-                ]),
-            )
-        }
-        ForeignCall {
-            foreign_symbol,
-            args,
-            ret_var,
-        } => {
-            // This is a modified version of what we do for function calls.
-
-            let ret_type = Variable(*ret_var);
-            let mut vars = Vec::with_capacity(1 + args.len());
-
-            vars.push(*ret_var);
-
-            // Canonicalize the function expression and its arguments
-
-            let mut arg_types = Vec::with_capacity(args.len());
-            let mut arg_cons = Vec::with_capacity(args.len());
-
-            for (index, (arg_var, arg_expr)) in args.iter().enumerate() {
-                let arg_type = Variable(*arg_var);
-
-                let reason = Reason::ForeignCallArg {
-                    foreign_symbol: foreign_symbol.clone(),
-                    arg_index: Index::zero_based(index),
-                };
-
-                let expected_arg = Expected::ForReason(reason, arg_type.clone(), region);
-                let arg_con = constrain_expr(
-                    env,
-                    var_store,
-                    var_usage,
-                    applied_usage_constraint,
-                    Region::zero(),
-                    arg_expr,
-                    expected_arg,
-                );
-
-                vars.push(*arg_var);
-                arg_types.push(arg_type);
-                arg_cons.push(arg_con);
-            }
-
-            let expected_uniq_type = var_store.fresh();
-            vars.push(expected_uniq_type);
-
-            let category = Category::ForeignCall;
-
-            exists(
-                vars,
-                And(vec![
-                    And(arg_cons),
-                    Eq(ret_type, expected, category, region),
-                ]),
-            )
-        }
-        LetRec(defs, loc_ret, var) => {
-            // NOTE doesn't currently unregister bound symbols
-            // may be a problem when symbols are not globally unique
-            let body_con = constrain_expr(
-                env,
-                var_store,
-                var_usage,
-                applied_usage_constraint,
-                loc_ret.region,
-                &loc_ret.value,
-                expected.clone(),
-            );
-
-            exists(
-                vec![*var],
-                And(vec![
-                    constrain_recursive_defs(
-                        env,
-                        var_store,
-                        var_usage,
-                        applied_usage_constraint,
-                        defs,
-                        body_con,
-                    ),
-                    // Record the type of tne entire def-expression in the variable.
-                    // Code gen will need that later!
-                    Eq(
-                        Type::Variable(*var),
-                        expected,
-                        Category::Storage(std::file!(), std::line!()),
-                        loc_ret.region,
-                    ),
-                ]),
-            )
-        }
-        LetNonRec(def, loc_ret, var) => {
-            // NOTE doesn't currently unregister bound symbols
-            // may be a problem when symbols are not globally unique
-            let body_con = constrain_expr(
-                env,
-                var_store,
-                var_usage,
-                applied_usage_constraint,
-                loc_ret.region,
-                &loc_ret.value,
-                expected.clone(),
-            );
-
-            exists(
-                vec![*var],
-                And(vec![
-                    constrain_def(
-                        env,
-                        var_store,
-                        var_usage,
-                        applied_usage_constraint,
-                        def,
-                        body_con,
-                    ),
-                    // Record the type of tne entire def-expression in the variable.
-                    // Code gen will need that later!
-                    Eq(
-                        Type::Variable(*var),
-                        expected,
-                        Category::Storage(std::file!(), std::line!()),
-                        loc_ret.region,
-                    ),
-                ]),
-            )
-        }
-        If {
-            cond_var,
-            branch_var,
-            branches,
-            final_else,
-        } => {
-            // TODO use Bool alias here, so we don't allocate this type every time
-            let bool_type = Type::Variable(Variable::BOOL);
-            let mut branch_cons = Vec::with_capacity(2 * branches.len() + 2);
-            let mut cond_uniq_vars = Vec::with_capacity(branches.len() + 2);
-
-            // TODO why does this cond var exist? is it for error messages?
-            let cond_uniq_var = var_store.fresh();
-            cond_uniq_vars.push(cond_uniq_var);
-            let cond_var_is_bool_con = Eq(
-                Type::Variable(*cond_var),
-                Expected::ForReason(
-                    Reason::IfCondition,
-                    attr_type(Bool::variable(cond_uniq_var), bool_type.clone()),
-                    region,
-                ),
-                Category::If,
-                Region::zero(),
-            );
-
-            branch_cons.push(cond_var_is_bool_con);
-
-            match expected {
-                Expected::FromAnnotation(name, arity, _, tipe) => {
-                    for (index, (loc_cond, loc_body)) in branches.iter().enumerate() {
-                        let cond_uniq_var = var_store.fresh();
-                        let expect_bool = Expected::ForReason(
-                            Reason::IfCondition,
-                            attr_type(Bool::variable(cond_uniq_var), bool_type.clone()),
-                            region,
-                        );
-                        cond_uniq_vars.push(cond_uniq_var);
-
-                        let cond_con = constrain_expr(
-                            env,
-                            var_store,
-                            var_usage,
-                            applied_usage_constraint,
-                            loc_cond.region,
-                            &loc_cond.value,
-                            expect_bool,
-                        );
-
-                        let then_con = constrain_expr(
-                            env,
-                            var_store,
-                            var_usage,
-                            applied_usage_constraint,
-                            loc_body.region,
-                            &loc_body.value,
-                            Expected::FromAnnotation(
-                                name.clone(),
-                                arity,
-                                AnnotationSource::TypedIfBranch {
-                                    index: Index::zero_based(index),
-                                    num_branches: branches.len(),
-                                },
-                                tipe.clone(),
-                            ),
-                        );
-
-                        branch_cons.push(cond_con);
-                        branch_cons.push(then_con);
-                    }
-                    let else_con = constrain_expr(
-                        env,
-                        var_store,
-                        var_usage,
-                        applied_usage_constraint,
-                        final_else.region,
-                        &final_else.value,
-                        Expected::FromAnnotation(
-                            name,
-                            arity,
-                            AnnotationSource::TypedIfBranch {
-                                index: Index::zero_based(branches.len()),
-                                num_branches: branches.len(),
-                            },
-                            tipe.clone(),
-                        ),
-                    );
-
-                    let ast_con = Eq(
-                        Type::Variable(*branch_var),
-                        Expected::NoExpectation(tipe),
-                        Category::Storage(std::file!(), std::line!()),
-                        region,
-                    );
-
-                    branch_cons.push(ast_con);
-                    branch_cons.push(else_con);
-
-                    cond_uniq_vars.push(*cond_var);
-                    cond_uniq_vars.push(*branch_var);
-
-                    exists(cond_uniq_vars, And(branch_cons))
-                }
-                _ => {
-                    for (index, (loc_cond, loc_body)) in branches.iter().enumerate() {
-                        let cond_uniq_var = var_store.fresh();
-                        let expect_bool = Expected::ForReason(
-                            Reason::IfCondition,
-                            attr_type(Bool::variable(cond_uniq_var), bool_type.clone()),
-                            region,
-                        );
-                        cond_uniq_vars.push(cond_uniq_var);
-
-                        let cond_con = constrain_expr(
-                            env,
-                            var_store,
-                            var_usage,
-                            applied_usage_constraint,
-                            loc_cond.region,
-                            &loc_cond.value,
-                            expect_bool,
-                        );
-
-                        let then_con = constrain_expr(
-                            env,
-                            var_store,
-                            var_usage,
-                            applied_usage_constraint,
-                            loc_body.region,
-                            &loc_body.value,
-                            Expected::ForReason(
-                                Reason::IfBranch {
-                                    index: Index::zero_based(index),
-                                    total_branches: branches.len(),
-                                },
-                                Type::Variable(*branch_var),
-                                region,
-                            ),
-                        );
-
-                        branch_cons.push(cond_con);
-                        branch_cons.push(then_con);
-                    }
-                    let else_con = constrain_expr(
-                        env,
-                        var_store,
-                        var_usage,
-                        applied_usage_constraint,
-                        final_else.region,
-                        &final_else.value,
-                        Expected::ForReason(
-                            Reason::IfBranch {
-                                index: Index::zero_based(branches.len()),
-                                total_branches: branches.len(),
-                            },
-                            Type::Variable(*branch_var),
-                            region,
-                        ),
-                    );
-
-                    branch_cons.push(Eq(
-                        Type::Variable(*branch_var),
-                        expected,
-                        Category::If,
-                        region,
-                    ));
-                    branch_cons.push(else_con);
-
-                    cond_uniq_vars.push(*cond_var);
-                    cond_uniq_vars.push(*branch_var);
-
-                    exists(cond_uniq_vars, And(branch_cons))
-                }
-            }
-        }
-        When {
-            cond_var,
-            expr_var,
-            loc_cond,
-            branches,
-            ..
-        } => {
-            let cond_var = *cond_var;
-            let cond_type = Variable(cond_var);
-            let expr_con = constrain_expr(
-                env,
-                var_store,
-                var_usage,
-                applied_usage_constraint,
-                region,
-                &loc_cond.value,
-                Expected::NoExpectation(cond_type.clone()),
-            );
-
-            let mut constraints = Vec::with_capacity(branches.len() + 1);
-            constraints.push(expr_con);
-
-            match &expected {
-                Expected::FromAnnotation(name, arity, _, typ) => {
-                    constraints.push(Eq(
-                        Type::Variable(*expr_var),
-                        expected.clone(),
-                        Category::When,
-                        region,
-                    ));
-
-                    for (index, when_branch) in branches.iter().enumerate() {
-                        let pattern_region =
-                            Region::across_all(when_branch.patterns.iter().map(|v| &v.region));
-
-                        let branch_con = constrain_when_branch(
-                            var_store,
-                            var_usage,
-                            applied_usage_constraint,
-                            env,
-                            region,
-                            when_branch,
-                            PExpected::ForReason(
-                                PReason::WhenMatch {
-                                    index: Index::zero_based(index),
-                                },
-                                cond_type.clone(),
-                                pattern_region,
-                            ),
-                            Expected::FromAnnotation(
-                                name.clone(),
-                                *arity,
-                                TypedWhenBranch {
-                                    index: Index::zero_based(index),
-                                },
-                                typ.clone(),
-                            ),
-                        );
-
-                        constraints.push(
-                            // Each branch's pattern must have the same type
-                            // as the condition expression did.
-                            branch_con,
-                        );
-                    }
-                }
-
-                _ => {
-                    let branch_type = Variable(*expr_var);
-                    let mut branch_cons = Vec::with_capacity(branches.len());
-
-                    for (index, when_branch) in branches.iter().enumerate() {
-                        let pattern_region =
-                            Region::across_all(when_branch.patterns.iter().map(|v| &v.region));
-                        let branch_con = constrain_when_branch(
-                            var_store,
-                            var_usage,
-                            applied_usage_constraint,
-                            env,
-                            region,
-                            when_branch,
-                            PExpected::ForReason(
-                                PReason::WhenMatch {
-                                    index: Index::zero_based(index),
-                                },
-                                cond_type.clone(),
-                                pattern_region,
-                            ),
-                            Expected::ForReason(
-                                Reason::WhenBranch {
-                                    index: Index::zero_based(index),
-                                },
-                                branch_type.clone(),
-                                region,
-                            ),
-                        );
-
-                        branch_cons.push(branch_con);
-                    }
-
-                    constraints.push(And(vec![
-                        // Each branch's pattern must have the same type
-                        // as the condition expression did.
-                        And(branch_cons),
-                        // The return type of each branch must equal
-                        // the return type of the entire case-expression.
-                        Eq(branch_type, expected, Category::When, region),
-                    ]))
-                }
-            }
-
-            exists(vec![cond_var, *expr_var], And(constraints))
-        }
-
-        Update {
-            record_var,
-            ext_var,
-            symbol,
-            updates,
-        } => {
-            let mut fields: SendMap<Lowercase, RecordField<Type>> = SendMap::default();
-            let mut vars = Vec::with_capacity(updates.len() + 2);
-            let mut cons = Vec::with_capacity(updates.len() + 3);
-            for (field_name, Field { var, loc_expr, .. }) in updates.clone() {
-                let (var, tipe, con) = constrain_field_update(
-                    env,
-                    var_store,
-                    var_usage,
-                    applied_usage_constraint,
-                    var,
-                    region,
-                    field_name.clone(),
-                    &loc_expr,
-                );
-                fields.insert(field_name, RecordField::Required(tipe));
-                vars.push(var);
-                cons.push(con);
-            }
-
-            let uniq_var = var_store.fresh();
-            vars.push(uniq_var);
-
-            let fields_type = attr_type(
-                Bool::variable(uniq_var),
-                Type::Record(fields, Box::new(Type::Variable(*ext_var))),
-            );
-            let record_type = Type::Variable(*record_var);
-
-            // NOTE from elm compiler: fields_type is separate so that Error propagates better
-            let fields_con = Eq(
-                record_type.clone(),
-                Expected::NoExpectation(fields_type),
-                Category::Record,
-                region,
-            );
-            let record_con = Eq(record_type.clone(), expected, Category::Record, region);
-
-            vars.push(*record_var);
-            vars.push(*ext_var);
-
-            let con = Lookup(
-                *symbol,
-                Expected::ForReason(
-                    Reason::RecordUpdateKeys(
-                        *symbol,
-                        updates
-                            .iter()
-                            .map(|(key, field)| (key.clone(), field.region))
-                            .collect(),
-                    ),
-                    record_type,
-                    region,
-                ),
-                region,
-            );
-
-            cons.push(con);
-            cons.push(fields_con);
-            cons.push(record_con);
-
-            exists(vars, And(cons))
-        }
-
-        Access {
-            record_var,
-            ext_var,
-            field_var,
-            loc_expr,
-            field,
-        } => {
-            let mut field_types = SendMap::default();
-
-            let field_uniq_var = var_store.fresh();
-            let field_uniq_type = Bool::variable(field_uniq_var);
-            let field_type = attr_type(field_uniq_type, Type::Variable(*field_var));
-
-            field_types.insert(field.clone(), RecordField::Demanded(field_type.clone()));
-
-            let record_uniq_var = var_store.fresh();
-            let record_uniq_type = Bool::container(record_uniq_var, vec![field_uniq_var]);
-            let record_type = attr_type(
-                record_uniq_type,
-                Type::Record(field_types, Box::new(Type::Variable(*ext_var))),
-            );
-
-            let category = Category::Access(field.clone());
-
-            let record_expected = Expected::NoExpectation(record_type);
-            let record_con = Eq(
-                Type::Variable(*record_var),
-                record_expected.clone(),
-                category.clone(),
-                region,
-            );
-
-            let inner_constraint = constrain_expr(
-                env,
-                var_store,
-                var_usage,
-                applied_usage_constraint,
-                loc_expr.region,
-                &loc_expr.value,
-                record_expected,
-            );
-
-            exists(
-                vec![
-                    *record_var,
-                    *field_var,
-                    *ext_var,
-                    field_uniq_var,
-                    record_uniq_var,
-                ],
-                And(vec![
-                    Eq(field_type, expected, category, region),
-                    inner_constraint,
-                    record_con,
-                ]),
-            )
-        }
-
-        Accessor {
-            function_var,
-            field,
-            record_var,
-            closure_var,
-            field_var,
-            ext_var,
-        } => {
-            let mut field_types = SendMap::default();
-
-            let field_uniq_var = var_store.fresh();
-            let field_uniq_type = Bool::variable(field_uniq_var);
-            let field_type = attr_type(field_uniq_type, Type::Variable(*field_var));
-
-            field_types.insert(field.clone(), RecordField::Demanded(field_type.clone()));
-
-            let record_uniq_var = var_store.fresh();
-            let record_uniq_type = Bool::container(record_uniq_var, vec![field_uniq_var]);
-            let record_type = attr_type(
-                record_uniq_type,
-                Type::Record(field_types, Box::new(Type::Variable(*ext_var))),
-            );
-
-            let category = Category::Accessor(field.clone());
-
-            let record_expected = Expected::NoExpectation(record_type.clone());
-            let record_con = Eq(
-                Type::Variable(*record_var),
-                record_expected,
-                category.clone(),
-                region,
-            );
-
-            let fn_uniq_var = var_store.fresh();
-            let closure_type = Type::Variable(*closure_var);
-            let fn_type = attr_type(
-                Bool::variable(fn_uniq_var),
-                Type::Function(
-                    vec![record_type],
-                    Box::new(closure_type),
-                    Box::new(field_type),
-                ),
-            );
-
-            exists(
-                vec![
-                    *record_var,
-                    *function_var,
-                    *closure_var,
-                    *field_var,
-                    *ext_var,
-                    fn_uniq_var,
-                    field_uniq_var,
-                    record_uniq_var,
-                ],
-                And(vec![
-                    Eq(fn_type.clone(), expected, category.clone(), region),
-                    Eq(
-                        fn_type,
-                        Expected::NoExpectation(Variable(*function_var)),
-                        category,
-                        region,
-                    ),
-                    record_con,
-                ]),
-            )
-        }
-        RuntimeError(_) => True,
-    }
-}
-
-fn constrain_var(
-    var_store: &mut VarStore,
-    applied_usage_constraint: &mut ImSet<Symbol>,
-    symbol_for_lookup: Symbol,
-    usage: Option<&Usage>,
-    region: Region,
-    expected: Expected<Type>,
-) -> Constraint {
-    use sharing::Mark::*;
-    use sharing::Usage::*;
-
-    match usage {
-        None | Some(Simple(Shared)) => {
-            // the variable is used/consumed more than once, so it must be Shared
-            let val_var = var_store.fresh();
-            let uniq_var = var_store.fresh();
-
-            let val_type = Variable(val_var);
-            let uniq_type = Bool::variable(uniq_var);
-
-            let attr_type = attr_type(uniq_type.clone(), val_type);
-
-            exists(
-                vec![val_var, uniq_var],
-                And(vec![
-                    Lookup(symbol_for_lookup, expected.clone(), region),
-                    Eq(attr_type, expected, Category::Uniqueness, region),
-                    Eq(
-                        Type::Boolean(uniq_type),
-                        Expected::NoExpectation(Type::Boolean(Bool::shared())),
-                        Category::Uniqueness,
-                        region,
-                    ),
-                ]),
-            )
-        }
-        Some(Simple(Unique)) | Some(Simple(Seen)) => {
-            // no additional constraints, keep uniqueness unbound
-            Lookup(symbol_for_lookup, expected, region)
-        }
-        Some(Usage::RecordAccess(_, _))
-        | Some(Usage::RecordUpdate(_, _))
-        | Some(Usage::ApplyAccess(_, _))
-        | Some(Usage::ApplyUpdate(_, _)) => {
-            applied_usage_constraint.insert(symbol_for_lookup);
-
-            let mut variables = Vec::new();
-            let (record_bool, inner_type) =
-                constrain_by_usage(&usage.expect("wut"), var_store, &mut variables);
-
-            let record_type = attr_type(record_bool, inner_type);
-
-            // NOTE breaking the expectation up like this REALLY matters!
-            let new_expected = Expected::NoExpectation(record_type.clone());
-            exists(
-                variables,
-                And(vec![
-                    Lookup(symbol_for_lookup, new_expected, region),
-                    Eq(record_type, expected, Category::Uniqueness, region),
-                ]),
-            )
-        }
-    }
-}
-
-fn constrain_by_usage(
-    usage: &Usage,
-    var_store: &mut VarStore,
-    introduced: &mut Vec<Variable>,
-) -> (Bool, Type) {
-    use Usage::*;
-
-    match usage {
-        Simple(Mark::Shared) => {
-            let var = var_store.fresh();
-
-            introduced.push(var);
-
-            (Bool::Shared, Type::Variable(var))
-        }
-        Simple(Mark::Seen) | Simple(Mark::Unique) => {
-            let var = var_store.fresh();
-            let uvar = var_store.fresh();
-
-            introduced.push(var);
-            introduced.push(uvar);
-
-            (Bool::container(uvar, vec![]), Type::Variable(var))
-        }
-        Usage::RecordAccess(mark, fields) => {
-            let (record_bool, ext_type) = constrain_by_usage(&Simple(*mark), var_store, introduced);
-
-            constrain_by_usage_record(fields, record_bool, ext_type, introduced, var_store)
-        }
-        Usage::RecordUpdate(_, fields) => {
-            let record_uvar = var_store.fresh();
-            introduced.push(record_uvar);
-
-            let record_bool = Bool::variable(record_uvar);
-
-            let ext_var = var_store.fresh();
-            let ext_type = Type::Variable(ext_var);
-            introduced.push(ext_var);
-
-            constrain_by_usage_record(fields, record_bool, ext_type, introduced, var_store)
-        }
-        Usage::ApplyAccess(mark, fields) => {
-            let (list_bool, _ext_type) = constrain_by_usage(&Simple(*mark), var_store, introduced);
-
-            // TODO reconsier this for multi-value applies
-            let field_usage = fields.get(0).expect("no LIST_ELEM key");
-
-            let (elem_bool, elem_type) = constrain_by_usage(field_usage, var_store, introduced);
-
-            match list_bool {
-                Bool::Shared => (
-                    Bool::Shared,
-                    Type::Apply(Symbol::LIST_LIST, vec![attr_type(Bool::Shared, elem_type)]),
-                ),
-                Bool::Container(list_uvar, list_mvars) => {
-                    debug_assert!(list_mvars.is_empty());
-
-                    match elem_bool {
-                        Bool::Shared => (
-                            Bool::variable(list_uvar),
-                            Type::Apply(
-                                Symbol::LIST_LIST,
-                                vec![attr_type(Bool::Shared, elem_type)],
-                            ),
-                        ),
-                        Bool::Container(cvar, mvars) => {
-                            debug_assert!(mvars.is_empty());
-                            (
-                                Bool::container(list_uvar, vec![cvar]),
-                                Type::Apply(
-                                    Symbol::LIST_LIST,
-                                    vec![attr_type(Bool::container(cvar, mvars), elem_type)],
-                                ),
-                            )
-                        }
-                    }
-                }
-            }
-        }
-
-        Usage::ApplyUpdate(_, fields) => {
-            let list_uvar = var_store.fresh();
-            introduced.push(list_uvar);
-
-            // TODO reconsier this for multi-value applies
-            let field_usage = fields.get(0).expect("no LIST_ELEM key");
-
-            let (elem_bool, elem_type) = constrain_by_usage(field_usage, var_store, introduced);
-
-            match elem_bool {
-                Bool::Shared => (
-                    Bool::variable(list_uvar),
-                    Type::Apply(Symbol::LIST_LIST, vec![attr_type(Bool::Shared, elem_type)]),
-                ),
-                Bool::Container(cvar, mvars) => {
-                    debug_assert!(mvars.is_empty());
-                    (
-                        Bool::container(list_uvar, vec![cvar]),
-                        Type::Apply(
-                            Symbol::LIST_LIST,
-                            vec![attr_type(Bool::container(cvar, mvars), elem_type)],
-                        ),
-                    )
-                }
-            }
-        }
-    }
-}
-
-fn constrain_by_usage_record(
-    fields: &FieldAccess,
-    record_bool: Bool,
-    ext_type: Type,
-    introduced: &mut Vec<Variable>,
-    var_store: &mut VarStore,
-) -> (Bool, Type) {
-    let mut field_types = SendMap::default();
-
-    match record_bool {
-        _ if fields.is_empty() => (record_bool, Type::Record(field_types, Box::new(ext_type))),
-        Bool::Shared => {
-            for (lowercase, nested_usage) in fields.clone().into_iter() {
-                let (_, nested_type) = constrain_by_usage(&nested_usage, var_store, introduced);
-
-                let field_type = attr_type(Bool::Shared, nested_type);
-
-                // In expressions, it's only possible to do record access on
-                // Required fields.
-                field_types.insert(lowercase.clone(), RecordField::Required(field_type));
-            }
-
-            (
-                Bool::Shared,
-                Type::Record(
-                    field_types,
-                    // TODO can we avoid doing Box::new on every single one of these?
-                    // For example, could we have a single lazy_static global Box they
-                    // could all share?
-                    Box::new(ext_type),
-                ),
-            )
-        }
-        Bool::Container(record_uniq_var, mvars) => {
-            debug_assert!(mvars.is_empty());
-
-            let mut uniq_vars = Vec::with_capacity(fields.len());
-
-            for (lowercase, nested_usage) in fields.clone().into_iter() {
-                let (nested_bool, nested_type) =
-                    constrain_by_usage(&nested_usage, var_store, introduced);
-
-                let field_type = match nested_bool {
-                    Bool::Container(uvar, atoms) => {
-                        for atom in &atoms {
-                            uniq_vars.push(*atom);
-                        }
-                        uniq_vars.push(uvar);
-                        attr_type(Bool::Container(uvar, atoms), nested_type)
-                    }
-                    Bool::Shared => attr_type(Bool::Shared, nested_type),
-                };
-
-                // In expressions, it's only possible to do record access on
-                // Required fields.
-                field_types.insert(lowercase.clone(), RecordField::Required(field_type));
-            }
-
-            (
-                Bool::container(record_uniq_var, uniq_vars),
-                Type::Record(
-                    field_types,
-                    // TODO can we avoid doing Box::new on every single one of these?
-                    // For example, could we have a single lazy_static global Box they
-                    // could all share?
-                    Box::new(ext_type),
-                ),
-            )
-        }
-    }
-}
-
-// TODO trim down these arguments
-#[allow(clippy::too_many_arguments)]
-// NOTE enabling the inline pragma can blow the stack in debug mode
-// #[inline(always)]
-fn constrain_when_branch(
-    var_store: &mut VarStore,
-    var_usage: &VarUsage,
-    applied_usage_constraint: &mut ImSet<Symbol>,
-    env: &Env,
-    region: Region,
-    when_branch: &WhenBranch,
-    pattern_expected: PExpected<Type>,
-    expr_expected: Expected<Type>,
-) -> Constraint {
-    let ret_constraint = constrain_expr(
-        env,
-        var_store,
-        var_usage,
-        applied_usage_constraint,
-        region,
-        &when_branch.value.value,
-        expr_expected,
-    );
-
-    let mut state = PatternState {
-        headers: SendMap::default(),
-        vars: Vec::with_capacity(1),
-        constraints: Vec::with_capacity(1),
-    };
-
-    for loc_pattern in &when_branch.patterns {
-        // mutates the state, so return value is not used
-        constrain_pattern(
-            env,
-            var_store,
-            var_usage,
-            applied_usage_constraint,
-            &mut state,
-            &loc_pattern,
-            pattern_expected.clone(),
-        );
-    }
-
-    if let Some(loc_guard) = &when_branch.guard {
-        let guard_uniq_var = var_store.fresh();
-
-        let bool_type = attr_type(
-            Bool::variable(guard_uniq_var),
-            Type::Variable(Variable::BOOL),
-        );
-
-        let guard_constraint = constrain_expr(
-            env,
-            var_store,
-            var_usage,
-            applied_usage_constraint,
-            loc_guard.region,
-            &loc_guard.value,
-            Expected::ForReason(Reason::WhenGuard, bool_type, loc_guard.region),
-        );
-
-        Constraint::Let(Box::new(LetConstraint {
-            rigid_vars: Vec::new(),
-            flex_vars: state.vars,
-            def_types: state.headers,
-            defs_constraint: Constraint::And(state.constraints),
-            ret_constraint: Constraint::Let(Box::new(LetConstraint {
-                rigid_vars: Vec::new(),
-                flex_vars: vec![guard_uniq_var],
-                def_types: SendMap::default(),
-                defs_constraint: guard_constraint,
-                ret_constraint,
-            })),
-        }))
-    } else {
-        Constraint::Let(Box::new(LetConstraint {
-            rigid_vars: Vec::new(),
-            flex_vars: state.vars,
-            def_types: state.headers,
-            defs_constraint: Constraint::And(state.constraints),
-            ret_constraint,
-        }))
-    }
-}
-
-fn constrain_def_pattern(
-    env: &Env,
-    var_store: &mut VarStore,
-    var_usage: &VarUsage,
-    applied_usage_constraint: &mut ImSet<Symbol>,
-    loc_pattern: &Located<Pattern>,
-    expr_type: Type,
-) -> PatternState {
-    // Exclude the current ident from shadowable_idents; you can't shadow yourself!
-    // (However, still include it in scope, because you *can* recursively refer to yourself.)
-    let pattern_expected = PExpected::NoExpectation(expr_type);
-
-    let mut state = PatternState {
-        headers: SendMap::default(),
-        vars: Vec::with_capacity(1),
-        constraints: Vec::with_capacity(1),
-    };
-
-    constrain_pattern(
-        env,
-        var_store,
-        var_usage,
-        applied_usage_constraint,
-        &mut state,
-        loc_pattern,
-        pattern_expected,
-    );
-
-    state
-}
-
-/// Turn e.g. `Int` into `Attr.Attr * Int`
-fn annotation_to_attr_type(
-    var_store: &mut VarStore,
-    ann: &Type,
-    rigids: &mut ImSet<Variable>,
-    change_var_kind: bool,
-) -> (Vec<Variable>, Type) {
-    use roc_types::types::Type::*;
-
-    match ann {
-        Variable(var) => {
-            if change_var_kind {
-                let uvar = var_store.fresh();
-                rigids.insert(uvar);
-                (
-                    vec![],
-                    attr_type(Bool::variable(uvar), Type::Variable(*var)),
-                )
-            } else {
-                (vec![], Type::Variable(*var))
-            }
-        }
-
-        Boolean(_) | Erroneous(_) => (vec![], ann.clone()),
-        EmptyRec | EmptyTagUnion => {
-            let uniq_var = var_store.fresh();
-            (
-                vec![uniq_var],
-                attr_type(Bool::variable(uniq_var), ann.clone()),
-            )
-        }
-
-        Function(arguments, closure, result) => {
-            let uniq_var = var_store.fresh();
-            let (mut arg_vars, args_lifted) =
-                annotation_to_attr_type_many(var_store, arguments, rigids, change_var_kind);
-
-            // NOTE: we don't lift the closure var!
-            // their uniqueness will never matter (it's a phantom parameter)
-            // and not lifting makes code reuse possible
-
-            let (result_vars, result_lifted) =
-                annotation_to_attr_type(var_store, result, rigids, change_var_kind);
-
-            arg_vars.extend(result_vars);
-            arg_vars.push(uniq_var);
-
-            match **closure {
-                Type::Variable(c) => arg_vars.push(c),
-                _ => unreachable!("closure must contain a type variable"),
-            }
-
-            (
-                arg_vars,
-                attr_type(
-                    Bool::variable(uniq_var),
-                    Type::Function(args_lifted, closure.clone(), Box::new(result_lifted)),
-                ),
-            )
-        }
-
-        Apply(Symbol::ATTR_ATTR, args) => {
-            let uniq_type = args[0].clone();
-
-            // A rigid behind an attr has already been lifted, don't do it again!
-            let (result_vars, result_lifted) = match args[1] {
-                Type::Variable(_) => match uniq_type {
-                    Type::Boolean(Bool::Container(urigid, _)) => (vec![urigid], args[1].clone()),
-                    _ => (vec![], args[1].clone()),
-                },
-                _ => annotation_to_attr_type(var_store, &args[1], rigids, change_var_kind),
-            };
-
-            let result = Apply(Symbol::ATTR_ATTR, vec![uniq_type, result_lifted]);
-
-            (result_vars, result)
-        }
-
-        Apply(symbol, args) => {
-            let uniq_var = var_store.fresh();
-
-            let (mut arg_vars, args_lifted) =
-                annotation_to_attr_type_many(var_store, args, rigids, change_var_kind);
-            let result = attr_type(Bool::variable(uniq_var), Type::Apply(*symbol, args_lifted));
-
-            arg_vars.push(uniq_var);
-
-            (arg_vars, result)
-        }
-
-        Record(fields, ext_type) => {
-            let uniq_var = var_store.fresh();
-            let mut vars = Vec::with_capacity(fields.len());
-            let mut lifted_fields = SendMap::default();
-
-            for (label, field) in fields.clone() {
-                use RecordField::*;
-
-                let lifted_field = match field {
-                    Demanded(tipe) => {
-                        let (new_vars, lifted_field) =
-                            annotation_to_attr_type(var_store, &tipe, rigids, change_var_kind);
-
-                        vars.extend(new_vars);
-
-                        Demanded(lifted_field)
-                    }
-                    Required(tipe) => {
-                        let (new_vars, lifted_field) =
-                            annotation_to_attr_type(var_store, &tipe, rigids, change_var_kind);
-
-                        vars.extend(new_vars);
-
-                        Required(lifted_field)
-                    }
-                    Optional(tipe) => {
-                        let (new_vars, lifted_field) =
-                            annotation_to_attr_type(var_store, &tipe, rigids, change_var_kind);
-
-                        vars.extend(new_vars);
-
-                        Optional(lifted_field)
-                    }
-                };
-
-                lifted_fields.insert(label, lifted_field);
-            }
-
-            vars.push(uniq_var);
-
-            (
-                vars,
-                attr_type(
-                    Bool::variable(uniq_var),
-                    Type::Record(lifted_fields, ext_type.clone()),
-                ),
-            )
-        }
-
-        TagUnion(tags, ext_type) => {
-            let uniq_var = var_store.fresh();
-            let mut vars = Vec::with_capacity(tags.len());
-            let mut lifted_tags = Vec::with_capacity(tags.len());
-
-            for (tag, fields) in tags {
-                let (new_vars, lifted_fields) =
-                    annotation_to_attr_type_many(var_store, fields, rigids, change_var_kind);
-                vars.extend(new_vars);
-                lifted_tags.push((tag.clone(), lifted_fields));
-            }
-
-            vars.push(uniq_var);
-
-            (
-                vars,
-                attr_type(
-                    Bool::variable(uniq_var),
-                    Type::TagUnion(lifted_tags, ext_type.clone()),
-                ),
-            )
-        }
-        RecursiveTagUnion(rec_var, tags, ext_type) => {
-            // In the case of
-            //
-            //      [ Cons a (List a), Nil ] as List a
-            //
-            // We need to lift it to
-            //
-            //      Attr u ([ Cons a (Attr u (List a)), Nil ] as List a)
-            //
-            // So the `u` of the whole recursive tag union is the same as the one used in the recursion
-
-            let uniq_var = var_store.fresh();
-            let mut vars = Vec::with_capacity(tags.len());
-            let mut lifted_tags = Vec::with_capacity(tags.len());
-
-            let mut substitutions = ImMap::default();
-            substitutions.insert(
-                *rec_var,
-                attr_type(Bool::variable(uniq_var), Type::Variable(*rec_var)),
-            );
-
-            for (tag, fields) in tags {
-                let (new_vars, mut lifted_fields) =
-                    annotation_to_attr_type_many(var_store, fields, rigids, change_var_kind);
-                vars.extend(new_vars);
-
-                for f in lifted_fields.iter_mut() {
-                    f.substitute(&substitutions);
-                }
-
-                lifted_tags.push((tag.clone(), lifted_fields));
-            }
-
-            vars.push(uniq_var);
-
-            let result = attr_type(
-                Bool::variable(uniq_var),
-                Type::RecursiveTagUnion(*rec_var, lifted_tags, ext_type.clone()),
-            );
-
-            (vars, result)
-        }
-
-        Alias(symbol, fields, actual) => {
-            let (mut actual_vars, lifted_actual) =
-                annotation_to_attr_type(var_store, actual, rigids, change_var_kind);
-
-            if let Type::Apply(attr_symbol, args) = lifted_actual {
-                debug_assert!(attr_symbol == Symbol::ATTR_ATTR);
-
-                let uniq_type = args[0].clone();
-                let actual_type = args[1].clone();
-
-                let mut new_fields = Vec::with_capacity(fields.len());
-                for (name, tipe) in fields {
-                    let (lifted_vars, lifted) =
-                        annotation_to_attr_type(var_store, tipe, rigids, change_var_kind);
-
-                    actual_vars.extend(lifted_vars);
-
-                    new_fields.push((name.clone(), lifted));
-                }
-
-                let alias = Type::Alias(*symbol, new_fields, Box::new(actual_type));
-
-                (
-                    actual_vars,
-                    crate::builtins::builtin_type(Symbol::ATTR_ATTR, vec![uniq_type, alias]),
-                )
-            } else {
-                panic!("lifted type is not Attr")
-            }
-        }
-        HostExposedAlias {
-            name: symbol,
-            arguments: fields,
-            actual_var,
-            actual,
-        } => {
-            let (mut actual_vars, lifted_actual) =
-                annotation_to_attr_type(var_store, actual, rigids, change_var_kind);
-
-            if let Type::Apply(attr_symbol, args) = lifted_actual {
-                debug_assert!(attr_symbol == Symbol::ATTR_ATTR);
-
-                let uniq_type = args[0].clone();
-                let actual_type = args[1].clone();
-
-                let mut new_fields = Vec::with_capacity(fields.len());
-                for (name, tipe) in fields {
-                    let (lifted_vars, lifted) =
-                        annotation_to_attr_type(var_store, tipe, rigids, change_var_kind);
-
-                    actual_vars.extend(lifted_vars);
-
-                    new_fields.push((name.clone(), lifted));
-                }
-
-                let alias = Type::HostExposedAlias {
-                    name: *symbol,
-                    arguments: new_fields,
-                    actual_var: *actual_var,
-                    actual: Box::new(actual_type),
-                };
-
-                (
-                    actual_vars,
-                    crate::builtins::builtin_type(Symbol::ATTR_ATTR, vec![uniq_type, alias]),
-                )
-            } else {
-                panic!("lifted type is not Attr")
-            }
-        }
-    }
-}
-
-fn annotation_to_attr_type_many(
-    var_store: &mut VarStore,
-    anns: &[Type],
-    rigids: &mut ImSet<Variable>,
-    change_var_kind: bool,
-) -> (Vec<Variable>, Vec<Type>) {
-    anns.iter()
-        .fold((Vec::new(), Vec::new()), |(mut vars, mut types), value| {
-            let (new_vars, tipe) =
-                annotation_to_attr_type(var_store, value, rigids, change_var_kind);
-            vars.extend(new_vars);
-            types.push(tipe);
-
-            (vars, types)
-        })
-}
-
-fn constrain_def(
-    env: &Env,
-    var_store: &mut VarStore,
-    var_usage: &VarUsage,
-    applied_usage_constraint: &mut ImSet<Symbol>,
-    def: &Def,
-    body_con: Constraint,
-) -> Constraint {
-    let expr_var = def.expr_var;
-    let expr_type = Type::Variable(expr_var);
-
-    let mut pattern_state = constrain_def_pattern(
-        env,
-        var_store,
-        var_usage,
-        applied_usage_constraint,
-        &def.loc_pattern,
-        expr_type.clone(),
-    );
-
-    pattern_state.vars.push(expr_var);
-
-    let mut new_rigids = Vec::new();
-
-    let expr_con = match &def.annotation {
-        Some(annotation) => {
-            let arity = annotation.signature.arity();
-            let mut ftv = env.rigids.clone();
-
-            let signature = instantiate_rigids(
-                var_store,
-                &annotation.signature,
-                &annotation.introduced_variables,
-                &mut new_rigids,
-                &mut ftv,
-                &def.loc_pattern,
-                &mut pattern_state.headers,
-            );
-
-            let annotation_expected = Expected::FromAnnotation(
-                def.loc_pattern.clone(),
-                arity,
-                AnnotationSource::TypedBody {
-                    region: annotation.region,
-                },
-                signature,
-            );
-
-            pattern_state.constraints.push(Eq(
-                expr_type,
-                annotation_expected.clone(),
-                Category::Storage(std::file!(), std::line!()),
-                Region::zero(),
-            ));
-
-            constrain_expr(
-                &Env {
-                    rigids: ftv,
-                    home: env.home,
-                },
-                var_store,
-                var_usage,
-                applied_usage_constraint,
-                def.loc_expr.region,
-                &def.loc_expr.value,
-                annotation_expected,
-            )
-        }
-        None => constrain_expr(
-            env,
-            var_store,
-            var_usage,
-            applied_usage_constraint,
-            def.loc_expr.region,
-            &def.loc_expr.value,
-            Expected::NoExpectation(expr_type),
-        ),
-    };
-
-    Let(Box::new(LetConstraint {
-        rigid_vars: new_rigids,
-        flex_vars: pattern_state.vars,
-        def_types: pattern_state.headers,
-        defs_constraint: Let(Box::new(LetConstraint {
-            rigid_vars: Vec::new(),        // always empty
-            flex_vars: Vec::new(),         // empty, because our functions have no arguments
-            def_types: SendMap::default(), // empty, because our functions have no arguments!
-            defs_constraint: And(pattern_state.constraints),
-            ret_constraint: expr_con,
-        })),
-        ret_constraint: body_con,
-    }))
-}
-
-fn constrain_closure_size(
-    name: Symbol,
-    region: Region,
-    captured_symbols: &[(Symbol, Variable)],
-    closure_var: Variable,
-    closure_ext_var: Variable,
-    variables: &mut Vec<Variable>,
-) -> Constraint {
-    debug_assert!(variables.iter().any(|s| *s == closure_var));
-    debug_assert!(variables.iter().any(|s| *s == closure_ext_var));
-
-    let mut tag_arguments = Vec::with_capacity(captured_symbols.len());
-    let mut captured_symbols_constraints = Vec::with_capacity(captured_symbols.len());
-
-    for (symbol, var) in captured_symbols {
-        // make sure the variable is registered
-        variables.push(*var);
-
-        // this symbol is captured, so it must be part of the closure type
-        tag_arguments.push(Type::Variable(*var));
-
-        // make the variable equal to the looked-up type of symbol
-        captured_symbols_constraints.push(Constraint::Lookup(
-            *symbol,
-            Expected::NoExpectation(Type::Variable(*var)),
-            Region::zero(),
-        ));
-    }
-
-    let tag_name = roc_module::ident::TagName::Closure(name);
-    let closure_type = Type::TagUnion(
-        vec![(tag_name, tag_arguments)],
-        Box::new(Type::Variable(closure_ext_var)),
-    );
-
-    let finalizer = Eq(
-        Type::Variable(closure_var),
-        Expected::NoExpectation(closure_type),
-        Category::ClosureSize,
-        region,
-    );
-
-    captured_symbols_constraints.push(finalizer);
-
-    Constraint::And(captured_symbols_constraints)
-}
-
-fn instantiate_rigids(
-    var_store: &mut VarStore,
-    annotation: &Type,
-    introduced_vars: &IntroducedVariables,
-    new_rigids: &mut Vec<Variable>,
-    ftv: &mut ImMap<Lowercase, (Variable, Variable)>,
-    loc_pattern: &Located<Pattern>,
-    headers: &mut SendMap<Symbol, Located<Type>>,
-) -> Type {
-    let unlifed_annotation = annotation.clone();
-    let mut annotation = annotation.clone();
-
-    let mut rigid_substitution: ImMap<Variable, Type> = ImMap::default();
-
-    for (name, var) in introduced_vars.var_by_name.iter() {
-        if let Some((existing_rigid, existing_uvar)) = ftv.get(&name) {
-            rigid_substitution.insert(
-                *var,
-                attr_type(
-                    Bool::variable(*existing_uvar),
-                    Type::Variable(*existing_rigid),
-                ),
-            );
-        } else {
-            // possible use this rigid in nested def's
-            let uvar = var_store.fresh();
-            ftv.insert(name.clone(), (*var, uvar));
-
-            new_rigids.push(*var);
-        }
-    }
-
-    // Instantiate rigid variables
-    if !rigid_substitution.is_empty() {
-        annotation.substitute(&rigid_substitution);
-    }
-
-    let mut new_uniqueness_rigids = ImSet::default();
-    let (mut uniq_vars, annotation) =
-        annotation_to_attr_type(var_store, &annotation, &mut new_uniqueness_rigids, true);
-
-    if let Pattern::Identifier(symbol) = loc_pattern.value {
-        headers.insert(symbol, Located::at(loc_pattern.region, annotation.clone()));
-    } else if let Some(new_headers) = crate::pattern::headers_from_annotation(
-        &loc_pattern.value,
-        &Located::at(loc_pattern.region, unlifed_annotation),
-    ) {
-        for (k, v) in new_headers {
-            let (new_uniq_vars, attr_annotation) =
-                annotation_to_attr_type(var_store, &v.value, &mut new_uniqueness_rigids, true);
-
-            uniq_vars.extend(new_uniq_vars);
-
-            headers.insert(k, Located::at(loc_pattern.region, attr_annotation));
-        }
-    }
-
-    new_rigids.extend(uniq_vars);
-    new_rigids.extend(introduced_vars.wildcards.iter().cloned());
-    new_rigids.extend(new_uniqueness_rigids);
-
-    annotation
-}
-
-fn constrain_recursive_defs(
-    env: &Env,
-    var_store: &mut VarStore,
-    var_usage: &VarUsage,
-    applied_usage_constraint: &mut ImSet<Symbol>,
-    defs: &[Def],
-    body_con: Constraint,
-) -> Constraint {
-    rec_defs_help(
-        env,
-        var_store,
-        var_usage,
-        applied_usage_constraint,
-        defs,
-        body_con,
-        Info::with_capacity(defs.len()),
-        Info::with_capacity(defs.len()),
-    )
-}
-
-#[allow(clippy::too_many_arguments)]
-pub fn rec_defs_help(
-    env: &Env,
-    var_store: &mut VarStore,
-    var_usage: &VarUsage,
-    applied_usage_constraint: &mut ImSet<Symbol>,
-    defs: &[Def],
-    body_con: Constraint,
-    mut rigid_info: Info,
-    mut flex_info: Info,
-) -> Constraint {
-    for def in defs {
-        let expr_var = def.expr_var;
-        let expr_type = Type::Variable(expr_var);
-
-        let pattern_expected = PExpected::NoExpectation(expr_type.clone());
-
-        let mut pattern_state = PatternState {
-            headers: SendMap::default(),
-            vars: flex_info.vars.clone(),
-            constraints: Vec::with_capacity(1),
-        };
-
-        pattern_state.vars.push(expr_var);
-
-        constrain_pattern(
-            env,
-            var_store,
-            var_usage,
-            applied_usage_constraint,
-            &mut pattern_state,
-            &def.loc_pattern,
-            pattern_expected,
-        );
-
-        // TODO see where aliases should go
-        let mut new_rigids = Vec::new();
-        match &def.annotation {
-            None => {
-                let expr_con = constrain_expr(
-                    env,
-                    var_store,
-                    var_usage,
-                    applied_usage_constraint,
-                    def.loc_expr.region,
-                    &def.loc_expr.value,
-                    Expected::NoExpectation(expr_type),
-                );
-
-                // TODO investigate if this let can be safely removed
-                let def_con = Let(Box::new(LetConstraint {
-                    rigid_vars: Vec::new(),
-                    flex_vars: Vec::new(), // empty because Roc function defs have no args
-                    def_types: SendMap::default(), // empty because Roc function defs have no args
-                    defs_constraint: True, // I think this is correct, once again because there are no args
-                    ret_constraint: expr_con,
-                }));
-
-                flex_info.vars = pattern_state.vars;
-                flex_info.constraints.push(def_con);
-                flex_info.def_types.extend(pattern_state.headers);
-            }
-
-            Some(annotation) => {
-                let arity = annotation.signature.arity();
-                let mut ftv = env.rigids.clone();
-                let signature = instantiate_rigids(
-                    var_store,
-                    &annotation.signature,
-                    &annotation.introduced_variables,
-                    &mut new_rigids,
-                    &mut ftv,
-                    &def.loc_pattern,
-                    &mut pattern_state.headers,
-                );
-                let annotation_expected = Expected::FromAnnotation(
-                    def.loc_pattern.clone(),
-                    arity,
-                    AnnotationSource::TypedBody {
-                        region: annotation.region,
-                    },
-                    signature.clone(),
-                );
-                let expr_con = constrain_expr(
-                    &Env {
-                        rigids: ftv,
-                        home: env.home,
-                    },
-                    var_store,
-                    var_usage,
-                    applied_usage_constraint,
-                    def.loc_expr.region,
-                    &def.loc_expr.value,
-                    annotation_expected.clone(),
-                );
-
-                // ensure expected type unifies with annotated type
-                let storage_con = Eq(
-                    expr_type,
-                    annotation_expected,
-                    Category::Storage(std::file!(), std::line!()),
-                    def.loc_expr.region,
-                );
-
-                // TODO investigate if this let can be safely removed
-                let def_con = Let(Box::new(LetConstraint {
-                    rigid_vars: Vec::new(),
-                    flex_vars: Vec::new(), // empty because Roc function defs have no args
-                    def_types: SendMap::default(), // empty because Roc function defs have no args
-                    defs_constraint: storage_con,
-                    ret_constraint: expr_con,
-                }));
-
-                rigid_info.vars.extend(&new_rigids);
-                rigid_info.constraints.push(Let(Box::new(LetConstraint {
-                    rigid_vars: new_rigids,
-                    flex_vars: pattern_state.vars,
-                    def_types: SendMap::default(), // no headers introduced (at this level)
-                    defs_constraint: def_con,
-                    ret_constraint: True,
-                })));
-                rigid_info.def_types.extend(pattern_state.headers);
-            }
-        }
-    }
-
-    Let(Box::new(LetConstraint {
-        rigid_vars: rigid_info.vars,
-        flex_vars: Vec::new(),
-        def_types: rigid_info.def_types,
-        defs_constraint: True,
-        ret_constraint: Let(Box::new(LetConstraint {
-            rigid_vars: Vec::new(),
-            flex_vars: flex_info.vars,
-            def_types: flex_info.def_types.clone(),
-            defs_constraint: Let(Box::new(LetConstraint {
-                rigid_vars: Vec::new(),
-                flex_vars: Vec::new(),
-                def_types: flex_info.def_types,
-                defs_constraint: True,
-                ret_constraint: And(flex_info.constraints),
-            })),
-            ret_constraint: And(vec![And(rigid_info.constraints), body_con]),
-        })),
-    }))
-}
-
-#[allow(clippy::too_many_arguments)]
-#[inline(always)]
-fn constrain_field_update(
-    env: &Env,
-    var_store: &mut VarStore,
-    var_usage: &VarUsage,
-    applied_usage_constraint: &mut ImSet<Symbol>,
-    var: Variable,
-    region: Region,
-    field: Lowercase,
-    loc_expr: &Located<Expr>,
-) -> (Variable, Type, Constraint) {
-    let field_type = Type::Variable(var);
-    let reason = Reason::RecordUpdateValue(field);
-    let expected = Expected::ForReason(reason, field_type.clone(), region);
-    let con = constrain_expr(
-        env,
-        var_store,
-        var_usage,
-        applied_usage_constraint,
-        loc_expr.region,
-        &loc_expr.value,
-        expected,
-    );
-
-    (var, field_type, con)
-}
diff --git a/compiler/fmt/tests/test_fmt.rs b/compiler/fmt/tests/test_fmt.rs
index 3b2d6e20fc..8e7cb1fbea 100644
--- a/compiler/fmt/tests/test_fmt.rs
+++ b/compiler/fmt/tests/test_fmt.rs
@@ -17,9 +17,12 @@ mod test_fmt {
     use roc_parse::ast::{Attempting, Expr};
     use roc_parse::blankspace::space0_before;
     use roc_parse::module::{self, module_defs};
-    use roc_parse::parser::{Bag, Parser, State};
+    use roc_parse::parser::{Bag, Parser, State, SyntaxError};
 
-    fn parse_with<'a>(arena: &'a Bump, input: &'a str) -> Result<Expr<'a>, Bag<'a>> {
+    fn parse_with<'a>(
+        arena: &'a Bump,
+        input: &'a str,
+    ) -> Result<Expr<'a>, Bag<'a, SyntaxError<'a>>> {
         let state = State::new_in(arena, input.trim().as_bytes(), Attempting::Module);
         let parser = space0_before(loc!(roc_parse::expr::expr(0)), 0);
         let answer = parser.parse(&arena, state);
diff --git a/compiler/gen/Cargo.toml b/compiler/gen/Cargo.toml
index 41420c9056..6480257d05 100644
--- a/compiler/gen/Cargo.toml
+++ b/compiler/gen/Cargo.toml
@@ -13,7 +13,6 @@ roc_problem = { path = "../problem" }
 roc_types = { path = "../types" }
 roc_builtins = { path = "../builtins" }
 roc_constrain = { path = "../constrain" }
-roc_uniq = { path = "../uniq" }
 roc_unify = { path = "../unify" }
 roc_solve = { path = "../solve" }
 roc_mono = { path = "../mono" }
diff --git a/compiler/gen_dev/Cargo.toml b/compiler/gen_dev/Cargo.toml
index f7c41ebbe0..0717943159 100644
--- a/compiler/gen_dev/Cargo.toml
+++ b/compiler/gen_dev/Cargo.toml
@@ -14,7 +14,6 @@ roc_problem = { path = "../problem" }
 roc_types = { path = "../types" }
 roc_builtins = { path = "../builtins" }
 roc_constrain = { path = "../constrain" }
-roc_uniq = { path = "../uniq" }
 roc_unify = { path = "../unify" }
 roc_solve = { path = "../solve" }
 roc_mono = { path = "../mono" }
diff --git a/compiler/load/tests/helpers/mod.rs b/compiler/load/tests/helpers/mod.rs
index 9d0c580249..ec8feb6b8c 100644
--- a/compiler/load/tests/helpers/mod.rs
+++ b/compiler/load/tests/helpers/mod.rs
@@ -15,7 +15,7 @@ use roc_module::ident::Ident;
 use roc_module::symbol::{IdentIds, Interns, ModuleId, ModuleIds, Symbol};
 use roc_parse::ast::{self, Attempting};
 use roc_parse::blankspace::space0_before;
-use roc_parse::parser::{loc, Bag, Parser, State};
+use roc_parse::parser::{loc, Bag, Parser, State, SyntaxError};
 use roc_problem::can::Problem;
 use roc_region::all::{Located, Region};
 use roc_solve::solve;
@@ -62,7 +62,10 @@ where
 }
 
 #[allow(dead_code)]
-pub fn parse_with<'a>(arena: &'a Bump, input: &'a str) -> Result<ast::Expr<'a>, Bag<'a>> {
+pub fn parse_with<'a>(
+    arena: &'a Bump,
+    input: &'a str,
+) -> Result<ast::Expr<'a>, Bag<'a, SyntaxError<'a>>> {
     parse_loc_with(arena, input).map(|loc_expr| loc_expr.value)
 }
 
@@ -70,7 +73,7 @@ pub fn parse_with<'a>(arena: &'a Bump, input: &'a str) -> Result<ast::Expr<'a>,
 pub fn parse_loc_with<'a>(
     arena: &'a Bump,
     input: &'a str,
-) -> Result<Located<ast::Expr<'a>>, Bag<'a>> {
+) -> Result<Located<ast::Expr<'a>>, Bag<'a, SyntaxError<'a>>> {
     let state = State::new_in(arena, input.trim().as_bytes(), Attempting::Module);
     let parser = space0_before(loc(roc_parse::expr::expr(0)), 0);
     let answer = parser.parse(&arena, state);
@@ -85,85 +88,6 @@ pub fn can_expr(expr_str: &str) -> CanExprOut {
     can_expr_with(&Bump::new(), test_home(), expr_str)
 }
 
-#[allow(dead_code)]
-pub fn uniq_expr(
-    expr_str: &str,
-) -> (
-    Located<Expr>,
-    Output,
-    Vec<Problem>,
-    Subs,
-    Variable,
-    Constraint,
-    ModuleId,
-    Interns,
-) {
-    let declared_idents: &ImMap<Ident, (Symbol, Region)> = &ImMap::default();
-
-    uniq_expr_with(&Bump::new(), expr_str, declared_idents)
-}
-
-#[allow(dead_code)]
-pub fn uniq_expr_with(
-    arena: &Bump,
-    expr_str: &str,
-    declared_idents: &ImMap<Ident, (Symbol, Region)>,
-) -> (
-    Located<Expr>,
-    Output,
-    Vec<Problem>,
-    Subs,
-    Variable,
-    Constraint,
-    ModuleId,
-    Interns,
-) {
-    let home = test_home();
-    let CanExprOut {
-        loc_expr,
-        output,
-        problems,
-        var_store: mut old_var_store,
-        var,
-        interns,
-        ..
-    } = can_expr_with(arena, home, expr_str);
-
-    // double check
-    let mut var_store = VarStore::new(old_var_store.fresh());
-
-    let expected2 = Expected::NoExpectation(Type::Variable(var));
-    let constraint = roc_constrain::uniq::constrain_declaration(
-        home,
-        &mut var_store,
-        Region::zero(),
-        &loc_expr,
-        declared_idents,
-        expected2,
-    );
-
-    let stdlib = uniq_stdlib();
-
-    let types = stdlib.types;
-    let imports: Vec<_> = types
-        .into_iter()
-        .map(|(symbol, (solved_type, region))| Import {
-            loc_symbol: Located::at(region, symbol),
-            solved_type,
-        })
-        .collect();
-
-    // load builtin values
-    let (_introduced_rigids, constraint) =
-        constrain_imported_values(imports, constraint, &mut var_store);
-
-    let subs2 = Subs::new(var_store.into());
-
-    (
-        loc_expr, output, problems, subs2, var, constraint, home, interns,
-    )
-}
-
 pub struct CanExprOut {
     pub loc_expr: Located<Expr>,
     pub output: Output,
diff --git a/compiler/mono/tests/helpers/mod.rs b/compiler/mono/tests/helpers/mod.rs
index be24114e88..ede19c36f2 100644
--- a/compiler/mono/tests/helpers/mod.rs
+++ b/compiler/mono/tests/helpers/mod.rs
@@ -15,7 +15,7 @@ use roc_module::ident::Ident;
 use roc_module::symbol::{IdentIds, Interns, ModuleId, ModuleIds, Symbol};
 use roc_parse::ast::{self, Attempting};
 use roc_parse::blankspace::space0_before;
-use roc_parse::parser::{loc, Bag, Parser, State};
+use roc_parse::parser::{loc, Bag, Parser, State, SyntaxError};
 use roc_problem::can::Problem;
 use roc_region::all::{Located, Region};
 use roc_solve::solve;
@@ -47,7 +47,10 @@ pub fn infer_expr(
 }
 
 #[allow(dead_code)]
-pub fn parse_with<'a>(arena: &'a Bump, input: &'a str) -> Result<ast::Expr<'a>, Bag<'a>> {
+pub fn parse_with<'a>(
+    arena: &'a Bump,
+    input: &'a str,
+) -> Result<ast::Expr<'a>, Bag<'a, SyntaxError<'a>>> {
     parse_loc_with(arena, input).map(|loc_expr| loc_expr.value)
 }
 
@@ -55,7 +58,7 @@ pub fn parse_with<'a>(arena: &'a Bump, input: &'a str) -> Result<ast::Expr<'a>,
 pub fn parse_loc_with<'a>(
     arena: &'a Bump,
     input: &'a str,
-) -> Result<Located<ast::Expr<'a>>, Bag<'a>> {
+) -> Result<Located<ast::Expr<'a>>, Bag<'a, SyntaxError<'a>>> {
     let state = State::new_in(arena, input.as_bytes(), Attempting::Module);
     let parser = space0_before(loc(roc_parse::expr::expr(0)), 0);
     let answer = parser.parse(&arena, state);
@@ -70,87 +73,6 @@ pub fn can_expr(expr_str: &str) -> CanExprOut {
     can_expr_with(&Bump::new(), test_home(), expr_str)
 }
 
-#[allow(dead_code)]
-pub fn uniq_expr(
-    expr_str: &str,
-) -> (
-    Located<Expr>,
-    Output,
-    Vec<Problem>,
-    Subs,
-    Variable,
-    Constraint,
-    ModuleId,
-    Interns,
-) {
-    let declared_idents: &ImMap<Ident, (Symbol, Region)> = &ImMap::default();
-
-    uniq_expr_with(&Bump::new(), expr_str, declared_idents)
-}
-
-#[allow(dead_code)]
-pub fn uniq_expr_with(
-    arena: &Bump,
-    expr_str: &str,
-    declared_idents: &ImMap<Ident, (Symbol, Region)>,
-) -> (
-    Located<Expr>,
-    Output,
-    Vec<Problem>,
-    Subs,
-    Variable,
-    Constraint,
-    ModuleId,
-    Interns,
-) {
-    let home = test_home();
-    let CanExprOut {
-        loc_expr,
-        output,
-        problems,
-        var_store: mut old_var_store,
-        var,
-        interns,
-        ..
-    } = can_expr_with(arena, home, expr_str);
-
-    // double check
-    let mut var_store = VarStore::new(old_var_store.fresh());
-
-    let expected2 = Expected::NoExpectation(Type::Variable(var));
-    let constraint = roc_constrain::uniq::constrain_declaration(
-        home,
-        &mut var_store,
-        Region::zero(),
-        &loc_expr,
-        declared_idents,
-        expected2,
-    );
-
-    let stdlib = uniq_stdlib();
-
-    let types = stdlib.types;
-    let imports: Vec<_> = types
-        .into_iter()
-        .map(|(symbol, (solved_type, region))| Import {
-            loc_symbol: Located::at(region, symbol),
-            solved_type,
-        })
-        .collect();
-
-    // load builtin values
-
-    // TODO what to do with those rigids?
-    let (_introduced_rigids, constraint) =
-        constrain_imported_values(imports, constraint, &mut var_store);
-
-    let subs2 = Subs::new(var_store.into());
-
-    (
-        loc_expr, output, problems, subs2, var, constraint, home, interns,
-    )
-}
-
 pub struct CanExprOut {
     pub loc_expr: Located<Expr>,
     pub output: Output,
diff --git a/compiler/parse/src/parser.rs b/compiler/parse/src/parser.rs
index 3ca41e08f2..1b6d61fafc 100644
--- a/compiler/parse/src/parser.rs
+++ b/compiler/parse/src/parser.rs
@@ -258,7 +258,7 @@ impl Progress {
     }
 }
 
-#[derive(Debug, Clone)]
+#[derive(Debug, Clone, PartialEq, Eq)]
 pub enum SyntaxError<'a> {
     Unexpected(Region),
     OutdentedTooFar,
@@ -278,7 +278,7 @@ pub enum SyntaxError<'a> {
 type Row = u32;
 type Col = u16;
 
-#[derive(Debug, Clone)]
+#[derive(Debug, Clone, PartialEq, Eq)]
 pub enum Type<'a> {
     TRecord(TRecord<'a>, Row, Col),
     ///
@@ -288,7 +288,7 @@ pub enum Type<'a> {
     TIndentStart(Row, Col),
 }
 
-#[derive(Debug, Clone)]
+#[derive(Debug, Clone, PartialEq, Eq)]
 pub enum TRecord<'a> {
     Open(Row, Col),
     End(Row, Col),
diff --git a/compiler/reporting/tests/helpers/mod.rs b/compiler/reporting/tests/helpers/mod.rs
index 60a0c05091..fd7400eca3 100644
--- a/compiler/reporting/tests/helpers/mod.rs
+++ b/compiler/reporting/tests/helpers/mod.rs
@@ -13,7 +13,7 @@ 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::blankspace::space0_before;
-use roc_parse::parser::{loc, Bag, Parser, State};
+use roc_parse::parser::{loc, Bag, Parser, State, SyntaxError};
 use roc_problem::can::Problem;
 use roc_region::all::Located;
 use roc_solve::solve;
@@ -101,7 +101,10 @@ pub struct CanExprOut {
 }
 
 #[allow(dead_code)]
-pub fn parse_with<'a>(arena: &'a Bump, input: &'a str) -> Result<ast::Expr<'a>, Bag<'a>> {
+pub fn parse_with<'a>(
+    arena: &'a Bump,
+    input: &'a str,
+) -> Result<ast::Expr<'a>, Bag<'a, SyntaxError<'a>>> {
     parse_loc_with(arena, input).map(|loc_expr| loc_expr.value)
 }
 
@@ -109,7 +112,7 @@ pub fn parse_with<'a>(arena: &'a Bump, input: &'a str) -> Result<ast::Expr<'a>,
 pub fn parse_loc_with<'a>(
     arena: &'a Bump,
     input: &'a str,
-) -> Result<Located<ast::Expr<'a>>, Bag<'a>> {
+) -> Result<Located<ast::Expr<'a>>, Bag<'a, SyntaxError<'a>>> {
     let state = State::new_in(arena, input.trim().as_bytes(), Attempting::Module);
     let parser = space0_before(loc(roc_parse::expr::expr(0)), 0);
     let answer = parser.parse(&arena, state);
@@ -121,7 +124,7 @@ pub fn parse_loc_with<'a>(
 
 #[derive(Debug)]
 pub struct ParseErrOut<'a> {
-    pub fail: Bag<'a>,
+    pub fail: Bag<'a, SyntaxError<'a>>,
     pub home: ModuleId,
     pub interns: Interns,
 }
diff --git a/compiler/solve/tests/helpers/mod.rs b/compiler/solve/tests/helpers/mod.rs
index 0ab9310383..5d8e05519e 100644
--- a/compiler/solve/tests/helpers/mod.rs
+++ b/compiler/solve/tests/helpers/mod.rs
@@ -15,7 +15,7 @@ use roc_module::ident::Ident;
 use roc_module::symbol::{IdentIds, Interns, ModuleId, ModuleIds, Symbol};
 use roc_parse::ast::{self, Attempting};
 use roc_parse::blankspace::space0_before;
-use roc_parse::parser::{loc, Bag, Parser, State};
+use roc_parse::parser::{loc, Bag, Parser, State, SyntaxError};
 use roc_problem::can::Problem;
 use roc_region::all::{Located, Region};
 use roc_solve::solve;
@@ -87,7 +87,10 @@ where
 }
 
 #[allow(dead_code)]
-pub fn parse_with<'a>(arena: &'a Bump, input: &'a str) -> Result<ast::Expr<'a>, Bag<'a>> {
+pub fn parse_with<'a>(
+    arena: &'a Bump,
+    input: &'a str,
+) -> Result<ast::Expr<'a>, Bag<'a, SyntaxError<'a>>> {
     parse_loc_with(arena, input).map(|loc_expr| loc_expr.value)
 }
 
@@ -95,7 +98,7 @@ pub fn parse_with<'a>(arena: &'a Bump, input: &'a str) -> Result<ast::Expr<'a>,
 pub fn parse_loc_with<'a>(
     arena: &'a Bump,
     input: &'a str,
-) -> Result<Located<ast::Expr<'a>>, Bag<'a>> {
+) -> Result<Located<ast::Expr<'a>>, Bag<'a, SyntaxError<'a>>> {
     let state = State::new_in(arena, input.trim().as_bytes(), Attempting::Module);
     let parser = space0_before(loc(roc_parse::expr::expr(0)), 0);
     let answer = parser.parse(&arena, state);
@@ -110,87 +113,6 @@ pub fn can_expr(expr_str: &str) -> CanExprOut {
     can_expr_with(&Bump::new(), test_home(), expr_str)
 }
 
-#[allow(dead_code)]
-pub fn uniq_expr(
-    expr_str: &str,
-) -> (
-    Located<Expr>,
-    Output,
-    Vec<Problem>,
-    Subs,
-    Variable,
-    Constraint,
-    ModuleId,
-    Interns,
-) {
-    let declared_idents: &ImMap<Ident, (Symbol, Region)> = &ImMap::default();
-
-    uniq_expr_with(&Bump::new(), expr_str, declared_idents)
-}
-
-#[allow(dead_code)]
-pub fn uniq_expr_with(
-    arena: &Bump,
-    expr_str: &str,
-    declared_idents: &ImMap<Ident, (Symbol, Region)>,
-) -> (
-    Located<Expr>,
-    Output,
-    Vec<Problem>,
-    Subs,
-    Variable,
-    Constraint,
-    ModuleId,
-    Interns,
-) {
-    let home = test_home();
-    let CanExprOut {
-        loc_expr,
-        output,
-        problems,
-        var_store: mut old_var_store,
-        var,
-        interns,
-        ..
-    } = can_expr_with(arena, home, expr_str);
-
-    // double check
-    let mut var_store = VarStore::new(old_var_store.fresh());
-
-    let expected2 = Expected::NoExpectation(Type::Variable(var));
-    let constraint = roc_constrain::uniq::constrain_declaration(
-        home,
-        &mut var_store,
-        Region::zero(),
-        &loc_expr,
-        declared_idents,
-        expected2,
-    );
-
-    let stdlib = uniq_stdlib();
-
-    let types = stdlib.types;
-    let imports: Vec<_> = types
-        .into_iter()
-        .map(|(symbol, (solved_type, region))| Import {
-            loc_symbol: Located::at(region, symbol),
-            solved_type,
-        })
-        .collect();
-
-    // load builtin values
-
-    // TODO what to do with those rigids?
-    let (_introduced_rigids, constraint) =
-        constrain_imported_values(imports, constraint, &mut var_store);
-
-    let subs2 = Subs::new(var_store.into());
-
-    (
-        loc_expr, output, problems, subs2, var, constraint, home, interns,
-    )
-}
-
 pub struct CanExprOut {
     pub loc_expr: Located<Expr>,
     pub output: Output,
diff --git a/editor/Cargo.toml b/editor/Cargo.toml
index 1270d358d6..d1b3b2a2d0 100644
--- a/editor/Cargo.toml
+++ b/editor/Cargo.toml
@@ -17,7 +17,6 @@ roc_problem = { path = "../compiler/problem" }
 roc_types = { path = "../compiler/types" }
 roc_builtins = { path = "../compiler/builtins" }
 roc_constrain = { path = "../compiler/constrain" }
-roc_uniq = { path = "../compiler/uniq" }
 roc_unify = { path = "../compiler/unify" }
 roc_solve = { path = "../compiler/solve" }
 roc_mono = { path = "../compiler/mono" }