Merge branch 'main' into main

.github/workflows/basic_cli_build_release.yml

@@ -7,6 +7,9 @@ concurrency:
   group: ${{ github.workflow }}-${{ github.ref }}
   cancel-in-progress: true
 
+# Do not add permissions here! Configure them at the job level!
+permissions: {}
+
 env:
   # use .tar.gz for quick testing
   ARCHIVE_FORMAT: .tar.br
@@ -183,7 +186,7 @@ jobs:
 
       - name: build basic-cli docs
         env:
-          ROC_DOCS_URL_ROOT: /packages/basic-cli/${{ env.RELEASE_TAG }}
+          ROC_DOCS_URL_ROOT: /basic-cli/${{ env.RELEASE_TAG }}
         run: |
           ./roc_nightly/roc docs ./basic-cli/platform/main.roc
           tar -czvf docs.tar.gz generated-docs/

.github/workflows/basic_cli_test_arm64.yml

@@ -7,6 +7,9 @@ concurrency:
   group: ${{ github.workflow }}-${{ github.ref }}
   cancel-in-progress: true
 
+# Do not add permissions here! Configure them at the job level!
+permissions: {}
+
 jobs:
   test-basic-cli-release-arm64:
     runs-on: [self-hosted, Linux, ARM64]

.github/workflows/basic_webserver_build_release.yml

@@ -7,6 +7,9 @@ concurrency:
   group: ${{ github.workflow }}-${{ github.ref }}
   cancel-in-progress: true
 
+# Do not add permissions here! Configure them at the job level!
+permissions: {}
+
 env:
   # use .tar.gz for quick testing
   ARCHIVE_FORMAT: .tar.br
@@ -168,3 +171,17 @@ jobs:
           name: basic-webserver-platform
           path: |
             ${{ env.TAR_FILENAME }}
+
+      - name: build basic-webserver docs
+        env:
+          ROC_DOCS_URL_ROOT: /basic-webserver/${{ env.RELEASE_TAG }}
+        run: |
+          ./roc_nightly/roc docs ./basic-webserver/platform/main.roc
+          tar -czvf docs.tar.gz generated-docs/
+
+      - name: Upload docs archive
+        uses: actions/upload-artifact@v4
+        with:
+          name: release-assets-docs
+          path: |
+            docs.tar.gz

.github/workflows/benchmarks.yml

@@ -3,6 +3,9 @@ on:
 
 name: Benchmarks
 
+# Do not add permissions here! Configure them at the job level!
+permissions: {}
+
 env:
   RUST_BACKTRACE: 1
   ROC_NUM_WORKERS: 1

.github/workflows/ci_cleanup.yml

@@ -4,6 +4,9 @@ on:
     - cron:  '0 5 * * 1'
 
 name: Garbage collect nix store
+
+# Do not add permissions here! Configure them at the job level!
+permissions: {}
     
 jobs:
   clean-big-ci:

.github/workflows/ci_cleanup_nix_mac.yml

@@ -4,6 +4,9 @@ on:
       - cron:  '0 5 * * *'
   
 name: Clean up nix on mac mini m1
+
+# Do not add permissions here! Configure them at the job level!
+permissions: {}
     
 jobs:
     clean-mac-mini-arm64:

.github/workflows/ci_manager.yml

@@ -1,12 +1,15 @@
-name: CI Manager
+on:
+  pull_request:
 
 # cancel current runs when a new commit is pushed
 concurrency:
     group: ${{ github.workflow }}-${{ github.ref }}
     cancel-in-progress: true
-    
-on:
-  pull_request:
+
+# Do not add permissions here! Configure them at the job level!
+permissions: {}
+
+name: CI Manager
 
 jobs:
   check-changes:
@@ -45,8 +48,8 @@ jobs:
               # Files that ci manager workflows should not run on.
               - '!.gitignore'
               - '!.reuse'
-              - '!AUTHORS'
-              - '!LEGAL_DETAILS'
+              - '!authors'
+              - '!legal_details'
               - '!LICENSE'
               - '!*.md'
               - '!src/**/*.md'

.github/workflows/ci_manager_old.yml

@@ -3,6 +3,9 @@ on:
 
 name: Old CI manager
 
+# Do not add permissions here! Configure them at the job level!
+permissions: {}
+
 jobs:
     check-changes:
         runs-on: ubuntu-22.04
@@ -16,7 +19,7 @@ jobs:
               id: check_ignored_files
               run: |
                 git fetch origin ${{ github.base_ref }}
-                if git diff --name-only origin/${{ github.base_ref }} HEAD | grep -qvE '(\.md$|\.css$|\.html$|^AUTHORS$)'; then
+                if git diff --name-only origin/${{ github.base_ref }} HEAD | grep -qvE '(\.md$|\.css$|\.html$|^authors$)'; then
                     echo "should_run_tests=y" >> $GITHUB_OUTPUT
                 else
                     echo "should_run_tests=n" >> $GITHUB_OUTPUT
@@ -36,7 +39,7 @@ jobs:
               id: check_rs_comments
               run: |
                 git fetch origin ${{ github.base_ref }}
-                if git diff --name-only origin/${{ github.base_ref }} HEAD | grep -qvE '(\.md$|\.css$|\.html$|^AUTHORS$|\.rs|\.roc)'; then
+                if git diff --name-only origin/${{ github.base_ref }} HEAD | grep -qvE '(\.md$|\.css$|\.html$|^authors$|\.rs|\.roc)'; then
                     echo "should_run_tests=y" >> $GITHUB_OUTPUT
                 else
                   if git diff --unified=0 origin/${{ github.base_ref }} HEAD '*.rs' | grep -E --color=never '^[+-]' | grep -qvE '^(\+\+\+|\-\-\-|[+-]\s*($|\/\/[^\/]|\/\*.*\*\/\s*$))'; then
@@ -50,7 +53,7 @@ jobs:
               id: check_roc_comments
               run: |
                 git fetch origin ${{ github.base_ref }}
-                if git diff --name-only origin/${{ github.base_ref }} HEAD | grep -qvE '(\.md$|\.css$|\.html$|^AUTHORS$|\.rs|\.roc)'; then
+                if git diff --name-only origin/${{ github.base_ref }} HEAD | grep -qvE '(\.md$|\.css$|\.html$|^authors$|\.rs|\.roc)'; then
                     echo "should_run_tests=y" >> $GITHUB_OUTPUT
                 else
                   if git diff --unified=0 origin/${{ github.base_ref }} HEAD '*.roc' | grep -E --color=never '^[+-]' | grep -qvE '^(\+\+\+|\-\-\-|[+-]\s*($|#))'; then

.github/workflows/ci_zig.yml

@@ -3,6 +3,9 @@ on:
 
 name: CI New Compiler
 
+# Do not add permissions here! Configure them at the job level!
+permissions: {}
+
 jobs:
     check-zig:
         runs-on: ubuntu-22.04

.github/workflows/devtools_test_linux_x86_64.yml

@@ -3,6 +3,9 @@ on:
 
 name: devtools nix files test - linux
 
+# Do not add permissions here! Configure them at the job level!
+permissions: {}
+
 jobs:
     devtools-test-linux:
         name: devtools-test-linux

.github/workflows/devtools_test_macos_apple_silicon.yml

@@ -3,6 +3,9 @@ on:
 
 name: devtools nix files test - macos
 
+# Do not add permissions here! Configure them at the job level!
+permissions: {}
+
 jobs:
     devtools-test-macos:
         name: devtools-test-mac

.github/workflows/docker.yml

@@ -4,6 +4,9 @@ on:
 
 name: Docker images tests
 
+# Do not add permissions here! Configure them at the job level!
+permissions: {}
+
 jobs:
   nightly-ubuntu-latest:
     name: nightly-ubuntu-latest

.github/workflows/fuzzer.yml

@@ -3,6 +3,9 @@ on:
 
 name: CI
 
+# Do not add permissions here! Configure them at the job level!
+permissions: {}
+
 env:
   RUST_BACKTRACE: 1
 

.github/workflows/macos_x86_64.yml

@@ -3,6 +3,9 @@ on:
 
 name: Macos x86-64 rust tests
 
+# Do not add permissions here! Configure them at the job level!
+permissions: {}
+
 env:
   RUST_BACKTRACE: 1
 

.github/workflows/markdown_link_check.yml

@@ -3,6 +3,9 @@ on:
   schedule:
     - cron: '0 9 * * *' # 9=9am utc+0
 
+# Do not add permissions here! Configure them at the job level!
+permissions: {}
+
 name: Check Markdown links
 
 jobs:

.github/workflows/nightly_linux_arm64.yml

@@ -6,6 +6,9 @@ on:
 
 name: Nightly Release Linux arm64/aarch64
 
+# Do not add permissions here! Configure them at the job level!
+permissions: {}
+
 jobs:
   build:
     name: build and package nightly release

.github/workflows/nightly_linux_x86_64.yml

@@ -6,6 +6,9 @@ on:
 
 name: Nightly Release Linux x86_64
 
+# Do not add permissions here! Configure them at the job level!
+permissions: {}
+
 jobs:
   build:
     name: build and package nightly release

.github/workflows/nightly_macos_apple_silicon.yml

@@ -6,6 +6,9 @@ on:
 
 name: Nightly Release macOS Apple Silicon
 
+# Do not add permissions here! Configure them at the job level!
+permissions: {}
+
 env:
   RUST_BACKTRACE: 1
   LLVM_SYS_180_PREFIX: /opt/homebrew/opt/llvm@18

.github/workflows/nightly_macos_x86_64.yml

@@ -6,6 +6,9 @@ on:
 
 name: Nightly Release macOS x86_64
 
+# Do not add permissions here! Configure them at the job level!
+permissions: {}
+
 env:
   LLVM_SYS_180_PREFIX: /usr/local/opt/llvm@18
 

.github/workflows/nightly_netlify_build_deploy.yml

@@ -3,6 +3,9 @@ on:
     - cron:  '0 9 * * *'
 
 name: Nightly netlify build and deploy
+
+# Do not add permissions here! Configure them at the job level!
+permissions: {}
     
 jobs:
   build:

.github/workflows/nix_linux_arm64_cargo.yml

@@ -6,6 +6,9 @@ name: test cargo build on linux arm64 inside nix
 env:
     RUST_BACKTRACE: 1
 
+# Do not add permissions here! Configure them at the job level!
+permissions: {}
+
 jobs:
     nix-linux-arm64-cargo:
         name: nix-linux-arm64

.github/workflows/nix_linux_arm64_default.yml

@@ -6,6 +6,9 @@ name: test default.nix on linux arm64
 env:
     RUST_BACKTRACE: 1
 
+# Do not add permissions here! Configure them at the job level!
+permissions: {}
+
 jobs:
     nix-linux-arm64-default:
         name: nix-linux-arm64

.github/workflows/nix_linux_x86_64.yml

@@ -6,6 +6,9 @@ name: Nix linux x86_64 cargo test
 env:
   RUST_BACKTRACE: 1
 
+# Do not add permissions here! Configure them at the job level!
+permissions: {}
+
 jobs:
   nix-linux-x86:
     name: nix-linux-x86

.github/workflows/nix_macos_apple_silicon.yml

@@ -3,6 +3,9 @@ on:
 
 name: Nix apple silicon cargo test
 
+# Do not add permissions here! Configure them at the job level!
+permissions: {}
+
 env:
   RUST_BACKTRACE: 1
 
@@ -22,23 +25,23 @@ jobs:
         run: nix develop -c cargo fmt --all -- --check
 
       - name: check code style with clippy
-        run: nix develop -c cargo clippy --workspace --tests -- --deny warnings
+        run: nix develop -c cargo clippy -j 2 --workspace --tests -- --deny warnings
 
       - name: check code style with clippy --release
-        run: nix develop -c cargo clippy --workspace --tests --release -- --deny warnings
+        run: nix develop -c cargo clippy -j 2 --workspace --tests --release -- --deny warnings
 
       - name: test building default.nix
         run: nix-build
 
       # for skipped tests: see issue 6274
       - name: execute tests with --release
-        run: nix develop -c cargo test --locked --release -- --skip cli_tests::inspect_gui --skip cli_tests::hello_gui
+        run: nix develop -c cargo test -j 1 --locked --release -- --skip cli_tests::inspect_gui --skip cli_tests::hello_gui
 
       - name: roc test all builtins
         run: nix develop -c ./ci/roc_test_builtins.sh
 
       - name: test aarch64 dev backend
-        run: nix develop -c cargo nextest-gen-dev --locked --release --no-fail-fast
+        run: nix develop -c cargo nextest-gen-dev -j 2 --locked --release --no-fail-fast
 
       # we run the llvm wasm tests only on this machine because it is fast and wasm should be cross-target
       - name: execute llvm wasm tests with --release

.github/workflows/nix_macos_x86_64.yml

@@ -3,6 +3,9 @@ on:
 
 name: Nix macOS x86_64 cargo test
 
+# Do not add permissions here! Configure them at the job level!
+permissions: {}
+
 env:
   RUST_BACKTRACE: 1
 

.github/workflows/spellcheck.yml

@@ -7,6 +7,9 @@ concurrency:
   group: ${{ github.workflow }}-${{ github.ref }}
   cancel-in-progress: true
 
+# Do not add permissions here! Configure them at the job level!
+permissions: {}
+
 env:
   RUST_BACKTRACE: 1
 

.github/workflows/stale.yml

@@ -1,8 +1,12 @@
 name: 'Close stale PRs'
+
 on:
   schedule:
     - cron: '30 1 * * *'
 
+# Do not add permissions here! Configure them at the job level!
+permissions: {}
+
 jobs:
   stale:
     runs-on: ubuntu-latest

.github/workflows/test_alpha_many_os.yml

@@ -4,6 +4,9 @@ on:
 
 name: Test latest alpha releases for macOS and Linux
 
+# Do not add permissions here! Configure them at the job level!
+permissions: {}
+
 jobs:
   test-alpha:
     name: test alpha macos 13 (x64), macos 14 (aarch64), ubuntu 22.04-24.04 (x64), ubuntu 22.04-24.04 (aarch64)

.github/workflows/test_nightly_many_os.yml

@@ -4,6 +4,9 @@ on:
 
 name: Test latest nightly releases for macOS and Linux
 
+# Do not add permissions here! Configure them at the job level!
+permissions: {}
+
 jobs:
   test-nightly:
     name: test nightly macos 13 (x64), macos 14 (aarch64), ubuntu 22.04-24.04 (x64), ubuntu 22.04-24.04 (aarch64)

.github/workflows/ubuntu_x86_64.yml

@@ -3,6 +3,9 @@ on:
 
 name: CI
 
+# Do not add permissions here! Configure them at the job level!
+permissions: {}
+
 env:
   RUST_BACKTRACE: 1
 
@@ -14,8 +17,8 @@ jobs:
     steps:
       - uses: actions/checkout@v4
 
-      - name: Check for duplicate AUTHORS
-        run: diff <(sort AUTHORS) <(sort AUTHORS | uniq) # The < operator treats a string as a file. diff 'succeeds' if no difference.
+      - name: Check for duplicate authors
+        run: diff <(sort authors) <(sort authors | uniq) # The < operator treats a string as a file. diff 'succeeds' if no difference.
 
       - name: Update PATH to use zig 13
         run: |

.github/workflows/ubuntu_x86_64_nix_debug.yml

@@ -3,6 +3,9 @@ on:
   
 name: cargo test debug nix
 
+# Do not add permissions here! Configure them at the job level!
+permissions: {}
+
 env:
     RUST_BACKTRACE: 1
 

.github/workflows/windows_release_build.yml

@@ -3,6 +3,9 @@ on:
 
 name: windows - release build
 
+# Do not add permissions here! Configure them at the job level!
+permissions: {}
+
 env:
   RUST_BACKTRACE: 1
 

.github/workflows/windows_tests.yml

@@ -3,6 +3,9 @@ on:
 
 name: windows - subset of tests
 
+# Do not add permissions here! Configure them at the job level!
+permissions: {}
+
 env:
   RUST_BACKTRACE: 1
 

.github/workflows/www.yml

@@ -1,5 +1,8 @@
 name: deploy www.roc-lang.org
 
+# Do not add permissions here! Configure them at the job level!
+permissions: {}
+
 on:
   # Allows you to run this workflow manually from the Actions tab
   workflow_dispatch:

.github/workflows/zulip_bot_high_p_issues.yml

@@ -1,5 +1,8 @@
 name: Notify zulip high priority issues
 
+# Do not add permissions here! Configure them at the job level!
+permissions: {}
+
 on:
   issues:
     types: [labeled]

.gitignore

@@ -8,9 +8,9 @@
 
 # Specifically keep these files with no extension
 !Earthfile
-!AUTHORS
+!authors
 !LICENSE*
-!LEGAL*
+!legal*
 !Dockerfile
 # .reuse/dep5 see https://reuse.software/
 !dep5

CONTRIBUTING.md

@@ -2,7 +2,7 @@
 
 ## Code of Conduct
 
-We are committed to providing a friendly, safe and welcoming environment for all. See our [Code of Conduct](CODE_OF_CONDUCT.md) for details.
+We are committed to providing a friendly, safe and welcoming environment for all. See our [Code of Conduct](code_of_conduct.md) for details.
 
 ## How to contribute
 

Glossary.md

@@ -0,0 +1,162 @@
+Here you can find definitions for words that are commonly used in the **compiler** along
+with links to the codebase. Check https://www.roc-lang.org/tutorial if you want to know 
+about general Roc terms. Feel free to ask for a term to be added or add one yourself!
+
+Contributor note: definitons should be roughly ordered like in a tutorial, e.g.
+Parser should be explained before Canonicalization. 
+
+## CLI
+
+Command Line Interface. The entrypoint of the compiler that brings together all
+functionality in the Roc toolset and makes it accessible to the user through the
+terminal, e.g. `roc build main.roc`.
+
+- new compiler: [src/main.zig](src/main.zig)
+- old compiler: [crates/cli/src/main.rs](crates/cli/src/main.rs)
+
+## Module
+
+A .roc file forms one module.
+
+Types of modules:
+- app [(example)](https://github.com/roc-lang/examples/blob/main/examples/HelloWorld/main.roc): Applications are combined with a platform and compiled into an executable.
+- module [(example)](https://github.com/roc-lang/examples/blob/main/examples/MultipleRocFiles/Hello.roc): Provide types and functions which can be imported into other modules.
+- package [(example)](https://github.com/lukewilliamboswell/roc-json/blob/main/package/main.roc): Organises modules to share functionality across applications and platforms.
+- platform [(example)](https://github.com/roc-lang/basic-cli/blob/main/platform/main.roc): Provides memory management and effects like writing to files, network communication,... to interface with the outside world. [Detailed explanation](https://www.roc-lang.org/platforms).
+- hosted [(example)](https://github.com/roc-lang/basic-cli/blob/main/platform/Host.roc): Lists all Roc types and functions provided by the platform.
+
+Implementation:
+- new compiler:
+  - [processing of modules](src/coordinate.zig)
+  - [folder with lots of module related things](src/base)
+- old compiler:
+  - [module folder](crates/compiler/module)
+
+## Identifier
+
+## Keyword
+
+## Operator
+
+## Syntax
+
+## Compiler Phase
+
+A compiler phase is a distinct stage in the process the compiler goes through to translate high-level source code into machine code that a computer can execute. Compilers don’t just do this in one big step, they break it down into several phases, each handling a specific task. Some examples of phases: [tokenization](#tokenization), [parsing](#parsing), [code generation](#code-gen),... .
+
+## Compiler Pass
+
+## Tokenization
+
+The process of breaking down source code into smaller units called tokens. These tokens are the basic building blocks of a programming language, such as [keywords](#Keyword), [identifiers](#identifier), [operators](#operator), and [symbols](#symbol). The input code is scanned character by character and is grouped into meaningful sequences based on the language's syntax rules.
+This step makes [parsing](#parsing) simpler.
+
+Example source code:
+```roc
+module []
+
+foo : U64
+```
+Corresponding tokens:
+```
+KwModule(1:1-1:7),OpenSquare(1:8-1:9),CloseSquare(1:9-1:10),Newline(1:1-1:1),
+Newline(1:1-1:1),
+LowerIdent(3:1-3:4),OpColon(3:5-3:6),UpperIdent(3:7-3:10),Newline(1:1-1:1)
+```
+
+New compiler:
+- [tokenize.zig](src/check/parse/tokenize.zig)
+
+Old compiler:
+- We did not do a separate tokenization step, everything happened in the [parser](crates/compiler/parse/src/parser.rs).
+
+## AST
+
+(Abstract Syntax Tree)
+
+An AST organizes and represents the source code as a tree-like structure.
+So for the code below:
+```roc
+module []
+
+foo : U64
+```
+
+The AST is:
+```
+(file
+    (module (1:1-1:10))
+    (type_anno (3:1-4:4)
+        "foo"
+        (tag (3:7-3:10) "U64")))
+```
+
+It captures the meaning of the code, while ignoring purely syntactic details like parentheses, commas, semicolons,... .
+Compared to raw source code, this structured format is much easier to analyze and manipulate programmatically by the next compiler phase.
+
+The AST is created by the [parser](#parsing).
+
+New compiler:
+- See the `Node` struct in [this file](src/check/parse/IR.zig).
+- You can see examples of ASTs in the .txt files in [this folder](src/snapshots).
+
+Old compiler:
+- See `FullAst` [here](crates/compiler/parse/src/ast.rs)
+- [Some tests](crates/compiler/parse/tests/test_parse.rs)
+- [Many snapshot tests](crates/compiler/test_syntax/tests/snapshots)
+
+## Parsing
+
+## Symbol
+
+## Closure
+
+## Canonicalization
+
+## Lambda Set
+
+## Type Inference
+
+## Monomorphization
+
+(mono, specialization)
+
+Monomorphization, also known as type specialization, is the process of creating a distinct copy
+of each instance of a generic function or value based on all specific usages in a program.
+For example; a function with the type `Num a -> Num a` may only be called in the program with a
+`U64` and a `I64`. Specialization will then create two functions with the types `U64 -> U64` and
+`I64 -> I64`.
+This trades off some compile time for a much better runtime performance, since we don't need to
+look up which implementation to call at runtime (AKA dynamic dispatch).
+
+Related Files:
+- new compiler:
+  - [specialize_functions.zig](src/build/specialize_functions.zig)
+  - [specialize_functions folder](src/build/specialize_functions)
+  - [specialize_types.zig](src/build/specialize_types.zig)
+  - [specialize types folder](src/build/specialize_types)
+  
+- old compiler:
+  - [mono folder](crates/compiler/mono)
+  - [mono tests](crates/compiler/test_mono)
+  - [mono macro tests](crates/compiler/test_mono_macros)
+
+## Type Checking
+
+## Reference Count
+
+## Alias Analysis
+
+## Code Gen
+
+## Host
+
+## Linking
+
+### Surgical Linker
+
+### Legacy Linker
+
+## Glue
+
+## WASM

README.md

@@ -6,7 +6,7 @@
 - [**tutorial**](https://roc-lang.org/tutorial)
 - [**docs** for the standard library](https://www.roc-lang.org/builtins)
 - [**examples**](https://www.roc-lang.org/examples)
-- [**faq**: frequently asked questions](https://github.com/roc-lang/roc/blob/main/www/content/faq.md)
+- [**faq**: frequently asked questions](https://www.roc-lang.org/faq)
 - [**group chat**](https://roc.zulipchat.com) for help, questions and discussions
 
 If you'd like to contribute, [get started here](CONTRIBUTING.md). Don't hesitate to ask for help on our [group chat](https://roc.zulipchat.com), we're friendly!

build.zig

@@ -43,9 +43,6 @@ pub fn build(b: *std.Build) void {
     const tracy_callstack = b.option(bool, "tracy-callstack", "Include callstack information with Tracy data. Does nothing if -Dtracy is not provided") orelse (tracy != null);
     const tracy_allocation = b.option(bool, "tracy-allocation", "Include allocation information with Tracy data. Does nothing if -Dtracy is not provided") orelse (tracy != null);
     const tracy_callstack_depth: u32 = b.option(u32, "tracy-callstack-depth", "Declare callstack depth for Tracy data. Does nothing if -Dtracy_callstack is not provided") orelse 10;
-    if (tracy != null and target.result.os.tag == .macos) {
-        std.log.warn("Tracy has significantly more overhead on MacOS. Be cautious when generating timing and analyzing results.", .{});
-    }
     if (tracy_callstack) {
         std.log.warn("Tracy callstack is enable. This can significantly skew timings, but is important for understanding source location. Be cautious when generating timing and analyzing results.", .{});
     }
@@ -53,7 +50,12 @@ pub fn build(b: *std.Build) void {
     // Create compile time build options
     const build_options = b.addOptions();
     build_options.addOption(bool, "enable_tracy", tracy != null);
-    build_options.addOption(bool, "enable_tracy_callstack", tracy_callstack);
+    if (target.result.os.tag == .macos and tracy_callstack) {
+        std.log.warn("Tracy callstack does not work on MacOS, disabling.", .{});
+        build_options.addOption(bool, "enable_tracy_callstack", false);
+    } else {
+        build_options.addOption(bool, "enable_tracy_callstack", tracy_callstack);
+    }
     build_options.addOption(bool, "enable_tracy_allocation", tracy_allocation);
     build_options.addOption(u32, "tracy_callstack_depth", tracy_callstack_depth);
 
@@ -271,6 +273,7 @@ fn add_tracy(
 
         base.root_module.addIncludePath(.{ .cwd_relative = tracy_path });
         base.root_module.addCSourceFile(.{ .file = .{ .cwd_relative = client_cpp }, .flags = tracy_c_flags });
+        base.root_module.addCSourceFile(.{ .file = .{ .cwd_relative = "src/tracy-shutdown.cpp" }, .flags = tracy_c_flags });
         if (!links_llvm) {
             base.root_module.linkSystemLibrary("c++", .{ .use_pkg_config = .no });
         }

build.zig.zon

@@ -55,6 +55,6 @@
         "build.zig.zon",
         "src",
         "LICENSE",
-        "LEGAL_DETAILS",
+        "legal_details",
     },
 }

ci/package_release.sh

@@ -10,7 +10,7 @@ strip ./target/release-with-lto/roc_language_server
 mkdir -p $1 $1/examples
 
 mv target/release-with-lto/{roc,roc_language_server,lib} $1
-mv LICENSE LEGAL_DETAILS $1
+mv LICENSE legal_details $1
 
 mv crates/cli/tests/platform-switching $1/examples
 mv examples/README.md $1/examples

crates/check/can_solo/src/desugar.rs

@@ -17,7 +17,7 @@ use roc_region::all::{Loc, Region};
 
 // BinOp precedence logic adapted from Gluon by Markus Westerlind
 // https://github.com/gluon-lang/gluon - license information can be found in
-// the LEGAL_DETAILS file in the root directory of this distribution.
+// the legal_details file in the root directory of this distribution.
 //
 // Thank you, Markus!
 

crates/cli_test_utils/src/helpers.rs

@@ -15,7 +15,7 @@ pub fn path_to_roc_binary() -> PathBuf {
 pub fn path_to_binary(binary_name: &str) -> PathBuf {
     // Adapted from https://github.com/volta-cli/volta/blob/cefdf7436a15af3ce3a38b8fe53bb0cfdb37d3dd/tests/acceptance/support/sandbox.rs#L680
     // by the Volta Contributors - license information can be found in
-    // the LEGAL_DETAILS file in the root directory of this distribution.
+    // the legal_details file in the root directory of this distribution.
     //
     // Thank you, Volta contributors!
     let mut path = env::var_os("CARGO_BIN_PATH")

crates/compiler/builtins/bitcode/src/utils.zig

@@ -179,10 +179,6 @@ pub const IncN = fn (?[*]u8, u64) callconv(.C) void;
 pub const Dec = fn (?[*]u8) callconv(.C) void;
 
 const REFCOUNT_MAX_ISIZE: isize = 0;
-// Only top bit set.
-const REFCOUNT_IS_ATOMIC_MASK: isize = std.math.minInt(isize);
-// All other bits of the refcount.
-const REFCOUNT_VALUE_MASK = ~REFCOUNT_IS_ATOMIC_MASK;
 
 pub const IntWidth = enum(u8) {
     U8 = 0,
@@ -203,7 +199,7 @@ const Refcount = enum {
     atomic,
 };
 
-const RC_TYPE: Refcount = .normal;
+const RC_TYPE: Refcount = .atomic;
 
 pub fn increfRcPtrC(ptr_to_refcount: *isize, amount: isize) callconv(.C) void {
     if (RC_TYPE == .none) return;
@@ -229,12 +225,7 @@ pub fn increfRcPtrC(ptr_to_refcount: *isize, amount: isize) callconv(.C) void {
                 ptr_to_refcount.* = refcount +% amount;
             },
             .atomic => {
-                // If the first bit of the refcount is set, this variable is atomic.
-                if (refcount & REFCOUNT_IS_ATOMIC_MASK != 0) {
-                    _ = @atomicRmw(isize, ptr_to_refcount, .Add, amount, .monotonic);
-                } else {
-                    ptr_to_refcount.* = refcount +% amount;
-                }
+                _ = @atomicRmw(isize, ptr_to_refcount, .Add, amount, .monotonic);
             },
             .none => unreachable,
         }
@@ -393,17 +384,9 @@ inline fn decref_ptr_to_refcount(
                 }
             },
             .atomic => {
-                // If the first bit of the refcount is set, this variable is atomic.
-                if (refcount_ptr[0] & REFCOUNT_IS_ATOMIC_MASK != 0) {
-                    const last = @atomicRmw(isize, &refcount_ptr[0], .Sub, 1, .monotonic);
-                    if (last & REFCOUNT_VALUE_MASK == 1) {
-                        free_ptr_to_refcount(refcount_ptr, alignment, elements_refcounted);
-                    }
-                } else {
-                    refcount_ptr[0] = refcount -% 1;
-                    if (refcount == 1) {
-                        free_ptr_to_refcount(refcount_ptr, alignment, elements_refcounted);
-                    }
+                const last = @atomicRmw(isize, &refcount_ptr[0], .Sub, 1, .monotonic);
+                if (last == 1) {
+                    free_ptr_to_refcount(refcount_ptr, alignment, elements_refcounted);
                 }
             },
             .none => unreachable,
@@ -437,7 +420,7 @@ pub inline fn rcUnique(refcount: isize) bool {
             return refcount == 1;
         },
         .atomic => {
-            return refcount & REFCOUNT_VALUE_MASK == 1;
+            return refcount == 1;
         },
         .none => {
             return false;
@@ -451,7 +434,7 @@ pub inline fn rcConstant(refcount: isize) bool {
             return refcount == REFCOUNT_MAX_ISIZE;
         },
         .atomic => {
-            return refcount & REFCOUNT_VALUE_MASK == REFCOUNT_MAX_ISIZE & REFCOUNT_VALUE_MASK;
+            return refcount == REFCOUNT_MAX_ISIZE;
         },
         .none => {
             return true;

crates/compiler/can/src/num.rs

@@ -211,7 +211,7 @@ fn parse_literal_suffix(num_str: &str) -> (Option<ParsedWidth>, &str) {
 ///
 /// The Rust Project is dual-licensed under either Apache 2.0 or MIT,
 /// at the user's choice. License information can be found in
-/// the LEGAL_DETAILS file in the root directory of this distribution.
+/// the legal_details file in the root directory of this distribution.
 ///
 /// Thanks to the Rust project and its contributors!
 fn from_str_radix(src: &str, radix: u32) -> Result<ParsedNumResult, IntErrorKind> {

crates/docs/src/lib.rs

@@ -246,38 +246,25 @@ fn render_package_index(docs_by_module: &[(ModuleId, ModuleDocumentation)]) -> S
         push_html(&mut module_list_buf, "li", [], link_buf.as_str());
     }
 
-    let header = {
-        let mut header_buf = String::new();
-
-        push_html(
-            &mut header_buf,
-            "h2",
-            [("class", "module-name")],
-            "Exposed Modules",
-        );
-
-        push_html(
-            &mut header_buf,
-            "a",
-            [
-                ("class", "llm-prompt-link"),
-                ("title", "Documentation in a LLM-friendly format"),
-                ("href", "llms.txt"),
-            ],
-            "LLM docs",
-        );
-
-        header_buf
-    };
-
     // The HTML for the index page
     let mut index_buf = String::new();
 
     push_html(
         &mut index_buf,
-        "div",
-        [("class", "module-header-container")],
-        &header,
+        "a",
+        [
+            ("class", "ai-docs-link"),
+            ("title", "Documentation in an AI-friendly format"),
+            ("href", "llms.txt"),
+        ],
+        "<span style=\"vertical-align: 2px;\">🤖</span> AI docs",
+    );
+
+    push_html(
+        &mut index_buf,
+        "h2",
+        [("class", "module-name")],
+        "Exposed Modules",
     );
 
     push_html(

crates/docs/src/static/styles.css

@@ -206,6 +206,7 @@ main {
   scrollbar-color: var(--violet) var(--body-bg-color);
   scrollbar-gutter: stable both-edges;
   scroll-padding-top: calc(16px + 16px + 1lh + 16px + 16px);
+  align-content: start;
 }
 
 main > * {
@@ -714,19 +715,8 @@ pre>samp {
   line-height: 1.3em;
 }
 
-.module-header-container {
-  display: flex;
-  justify-content: space-between;
-  align-items: flex-end;
-  margin-bottom: 48px;
-}
-
-.llm-prompt-link {
-  flex-shrink: 0;
-}
-
-.module-name {
-    flex-grow: 1;
+.ai-docs-link {
+  margin-bottom: 10px;
 }
 
 @media (prefers-color-scheme: dark) {

crates/linker/src/elf.rs

@@ -1458,7 +1458,7 @@ fn surgery_elf_help(
                         }
                     } else {
                         internal_error!(
-                            "Undefined Symbol in relocation, {:+x?}: {:+x?} try compiling with --linker legacy",
+                            "Undefined Symbol in relocation, {:+x?}: {:+x?}\n\nTIP: try compiling with `--linker legacy`",
                             rel,
                             app_obj.symbol_by_index(index)
                         );

crates/repl_test/src/cli.rs

@@ -18,7 +18,7 @@ pub struct Out {
 fn path_to_roc_binary() -> PathBuf {
     // Adapted from https://github.com/volta-cli/volta/blob/cefdf7436a15af3ce3a38b8fe53bb0cfdb37d3dd/tests/acceptance/support/sandbox.rs#L680
     // by the Volta Contributors - license information can be found in
-    // the LEGAL_DETAILS file in the root directory of this distribution.
+    // the legal_details file in the root directory of this distribution.
     //
     // Thank you, Volta contributors!
     let mut path = env::var_os("CARGO_BIN_PATH")

devtools/debug_tips.md

@@ -31,10 +31,11 @@ Note that the addresses shown in objdump may use a different offset compared to
 1. [Download here](https://hex-rays.com/ida-free/)
 2. Build your roc app with the legacy linker if it does not error only with the surgical linker: `roc build myApp.roc --linker=legacy`
 3. Open the produced executable with IDA free, don't change any of the suggested settings.
-4. You probably want to go to the function you saw in valgrind like `List_walkTryHelp_...` [here](https://github.com/roc-lang/examples/pull/192#issuecomment-2269571439). You can use Ctrl+F in the Function s window in IDA free.
-5. Right click and choose `Add Breakpoint` at the first instruction of the function you clicked on the previous step.
-6. Run the debugger by pressing F9
-7. Use step into (F7) and step over (F8) to see what's going on. Keep an eye on the `General Registers` and `Stack view` windows while you're stepping.
+4. If IDA ever asks for the path for roc_app, just click cancel.
+5. You probably want to go to the function you saw in valgrind like `List_walkTryHelp_...` [here](https://github.com/roc-lang/examples/pull/192#issuecomment-2269571439). You can use Ctrl+F in the Function s window in IDA free.
+6. Right click and choose `Add Breakpoint` at the first instruction of the function you clicked on the previous step.
+7. Run the debugger by pressing F9
+8. Use step into (F7) and step over (F8) to see what's going on. Keep an eye on the `General Registers` and `Stack view` windows while you're stepping.
 
 
 #### gdb

devtools/smart_diff_utrace.html

@@ -161,62 +161,89 @@
         function processTrace(trace, otherTrace, resultId) {
             const lines = trace.trim().split('\n');
             const otherLines = otherTrace.trim().split('\n');
-            let contentHtml = '';
-            let lineNumbersHtml = '';
-            let indentLevel = 0;
-            let blockStartLine = -1;
+            const container = document.createElement('div');
+            const lineNumbersDiv = document.createElement('div');
+            const contentAreaDiv = document.createElement('div');
             
+            lineNumbersDiv.className = 'line-numbers';
+            contentAreaDiv.className = 'content-area';
+            container.appendChild(lineNumbersDiv);
+            container.appendChild(contentAreaDiv);
+
             // Generate line numbers
             for (let i = 1; i <= lines.length; i++) {
-                lineNumbersHtml += `${i}\n`;
+                const lineNum = document.createElement('div');
+                lineNum.textContent = i;
+                lineNumbersDiv.appendChild(lineNum);
             }
-            
+
+            let indentLevel = 0;
+            let currentBlock = contentAreaDiv;
+
             for (let i = 0; i < lines.length; i++) {
                 const line = lines[i].trim();
                 const shouldHighlight = !otherLines.some(otherLine => otherLine.trim() === line);
                 const highlightClass = shouldHighlight ? 'highlight' : '';
-
                 const isBlockStart = line.endsWith('{') && i < lines.length - 1;
-                
+
                 if (isBlockStart) {
-                    blockStartLine = i;
-                    const functionName = line;
-                    contentHtml += `<div class="function-block" style="margin-left: ${indentLevel * 20}px">
-                        <div class="function-header ${highlightClass}">
-                            <span class="toggle-btn">▼</span>
-                            <span class="function-name">${functionName}</span>
-                        </div>
-                        <div class="function-content">`;
+                    const functionBlock = document.createElement('div');
+                    const header = document.createElement('div');
+                    const toggleBtn = document.createElement('span');
+                    const functionName = document.createElement('span');
+                    const content = document.createElement('div');
+
+                    functionBlock.className = 'function-block';
+                    functionBlock.style.marginLeft = `${indentLevel * 20}px`;
+                    header.className = `function-header ${highlightClass}`;
+                    toggleBtn.className = 'toggle-btn';
+                    toggleBtn.textContent = '▼';
+                    functionName.className = 'function-name';
+                    functionName.textContent = line;
+                    content.className = 'function-content';
+
+                    header.appendChild(toggleBtn);
+                    header.appendChild(functionName);
+                    functionBlock.appendChild(header);
+                    functionBlock.appendChild(content);
+                    currentBlock.appendChild(functionBlock);
+
                     indentLevel++;
+                    currentBlock = content;
                 } else if (line.includes('}')) {
                     if (indentLevel > 0) {
                         indentLevel--;
-                        contentHtml += `</div><span class="function-end ${highlightClass}">${line}</span></div>`;
+                        const endSpan = document.createElement('span');
+                        endSpan.className = `function-end ${highlightClass}`;
+                        endSpan.textContent = line;
+                        currentBlock.appendChild(endSpan);
+                        currentBlock = currentBlock.parentElement.parentElement; // Move up to parent block
                     } else {
-                        contentHtml += `<div class="line ${highlightClass}">${line}</div>`;
+                        const lineDiv = document.createElement('div');
+                        lineDiv.className = `line ${highlightClass}`;
+                        lineDiv.textContent = line;
+                        currentBlock.appendChild(lineDiv);
                     }
                 } else {
-                    const isLastLineBlock = line.endsWith('{') && i === lines.length - 1;
-                    if (isLastLineBlock) {
-                        contentHtml += `<div class="line ${highlightClass}">${line}</div>`;
-                    } else {
-                        contentHtml += `<div class="line ${highlightClass}">${line}</div>`;
-                    }
+                    const lineDiv = document.createElement('div');
+                    lineDiv.className = `line ${highlightClass}`;
+                    lineDiv.textContent = line;
+                    currentBlock.appendChild(lineDiv);
                 }
             }
-            
-            return `<div class="line-numbers">${lineNumbersHtml}</div><div class="content-area">${contentHtml}</div>`;
+
+            return container;
         }
 
         function initializeCollapsible(containerId) {
             const container = document.getElementById(containerId);
             const functionBlocks = container.querySelectorAll('.function-block');
-            
+
             functionBlocks.forEach(block => {
                 const header = block.querySelector('.function-header');
                 const toggleBtn = block.querySelector('.toggle-btn');
-                
-                header.addEventListener('click', (e) => {
+
+                header.addEventListener('click', () => {
                     block.classList.toggle('collapsed');
                     toggleBtn.textContent = block.classList.contains('collapsed') ? '▶' : '▼';
                 });
@@ -227,8 +254,13 @@
             const trace1 = document.getElementById('input1').value;
             const trace2 = document.getElementById('input2').value;
 
-            document.getElementById('result1').innerHTML = processTrace(trace1, trace2, 'result1');
-            document.getElementById('result2').innerHTML = processTrace(trace2, trace1, 'result2');
+            const result1 = document.getElementById('result1');
+            const result2 = document.getElementById('result2');
+            result1.innerHTML = ''; // Clear previous content
+            result2.innerHTML = ''; // Clear previous content
+
+            result1.appendChild(processTrace(trace1, trace2, 'result1'));
+            result2.appendChild(processTrace(trace2, trace1, 'result2'));
 
             initializeCollapsible('result1');
             initializeCollapsible('result2');

examples/README.md

@@ -1,3 +1,3 @@
 # Examples
 
-Checkout the [roc examples site](https://github.com/roc-lang/examples) to see examples of using roc.
+Checkout the [roc examples site](https://www.roc-lang.org/examples) to see examples of using roc.

flake.nix

@@ -97,6 +97,7 @@
            
           zls # zig language server
           watchexec
+          simple-http-server # to view the website locally
         ]);
 
         aliases = ''

nix/simple-http-server.nix

@@ -1,6 +1,14 @@
-{ rustPlatform, fetchFromGitHub }:
+{
+  lib,
+  stdenv,
+  rustPlatform,
+  fetchFromGitHub,
+  pkg-config,
+  openssl,
+  darwin,
+}:
 
-rustPlatform.buildRustPackage {
+rustPlatform.buildRustPackage rec {
   pname = "simple-http-server";
   version = "0.1.0";  # adjust version as needed
   
@@ -8,9 +16,18 @@ rustPlatform.buildRustPackage {
     owner = "Anton-4";
     repo = "simple-http-server";
     rev = "f3089e5736a1e8abdb69ba9e7618fe5e518a2df0";
+    sha256 = "sha256-Vcckv75hmJV7F9mqPtM3piSIZg9MvKI/oU7/tv4viy4=";
   };
   
   cargoLock = {
     lockFile = "${src}/Cargo.lock";
   };
+
+  nativeBuildInputs = [ pkg-config ];
+
+  buildInputs =
+    [ openssl ]
+    ++ lib.optionals stdenv.hostPlatform.isDarwin [
+      darwin.apple_sdk.frameworks.Security
+    ];
 }

src/README.profiling.md

@@ -80,11 +80,9 @@ Often times, it is worth profiling once with `-Dtracy-callstack=false` to have m
 Now that I have the compiler built with tracy, I can launch the tracy server on my mac machine to record the result (you can also run it on the same machine if wanted).
 Run `tracy-profiler`, input the correct ip address, and press connect.
 Then run the instrumented version of zig: `./zig-out/bin/roc format /tmp/new.roc`.
-For best results `export TRACY_NO_EXIT=1` before running. This ensures that all tracing data is uploaded before roc exits.
 Also, run with the root user to capture more information.
 In this case, I ran:
 ```
-export TRACY_NO_EXIT=1
 sudo ./zig-out/bin/roc format /tmp/new.roc
 ```
 

src/base/Ident.zig

@@ -62,6 +62,15 @@ pub const Store = struct {
     attributes: std.ArrayListUnmanaged(Attributes) = .{},
     next_unique_name: u32 = 0,
 
+    /// Initialize the memory for an `Ident.Store` with a specific capaicty.
+    pub fn initCapacity(gpa: std.mem.Allocator, capacity: usize) Store {
+        return .{
+            .interner = SmallStringInterner.initCapacity(gpa, capacity),
+            .exposing_modules = std.ArrayListUnmanaged(ModuleImport.Idx).initCapacity(gpa, capacity) catch |err| exitOnOom(err),
+            .attributes = std.ArrayListUnmanaged(Attributes).initCapacity(gpa, capacity) catch |err| exitOnOom(err),
+        };
+    }
+
     /// Deinitialize the memory for an `Ident.Store`.
     pub fn deinit(self: *Store, gpa: std.mem.Allocator) void {
         self.interner.deinit(gpa);

src/base/ModuleEnv.zig

@@ -25,12 +25,13 @@ problems: Problem.List,
 
 /// Initialize the module environment.
 pub fn init(gpa: std.mem.Allocator) Self {
+    // TODO: maybe wire in smarter default based on the initial input text size.
     return Self{
         .gpa = gpa,
-        .idents = .{},
-        .ident_ids_for_slicing = .{},
-        .strings = .{},
-        .problems = .{},
+        .idents = Ident.Store.initCapacity(gpa, 256),
+        .ident_ids_for_slicing = collections.SafeList(Ident.Idx).initCapacity(gpa, 64),
+        .strings = StringLiteral.Store.initCapacityBytes(gpa, 256),
+        .problems = Problem.List.initCapacity(gpa, 16),
     };
 }
 

src/base/StringLiteral.zig

@@ -33,6 +33,15 @@ pub const Store = struct {
     /// continues to the previous byte
     buffer: std.ArrayListUnmanaged(u8) = .{},
 
+    /// Intiizalizes a `StringLiteral.Store` with capacity `bytes` of space.
+    /// Note this specifically is the number of bytes for storing strings.
+    /// The string `hello, world!` will use 14 bytes including the null terminator.
+    pub fn initCapacityBytes(gpa: std.mem.Allocator, bytes: usize) Store {
+        return .{
+            .buffer = std.ArrayListUnmanaged(u8).initCapacity(gpa, bytes) catch |err| exitOnOom(err),
+        };
+    }
+
     /// Deinitialize a `StringLiteral.Store`'s memory.
     pub fn deinit(self: *Store, gpa: std.mem.Allocator) void {
         self.buffer.deinit(gpa);

src/build/specialize_types/IR.zig

@@ -1,13 +1,5 @@
 //! The intermediate representation (IR) for a Roc module that has been monomorphized.
 //!
-//! Monomorphization, also known as type specialization, is the process of creating a distinct copy
-//! of each instance of a generic function or value based on all specific usages in a program.
-//! For example; a function with the type `Num a -> Num a` may only be called in the program with a
-//! `U64` and a `I64`. Specialization will then create two functions with the types `U64 -> U64` and
-//! `I64 -> I64`.
-//! This trades off some compile time for a much better runtime performance, since we don't need to
-//! look up which implementation to call at runtime (AKA dynamic dispatch).
-//!
 //! Doing type specialization as the first build stage helps simplify compilation of lambda sets, or
 //! values captured by closures.
 //!

src/check/parse/IR.zig

@@ -31,7 +31,7 @@ tokens: TokenizedBuffer,
 store: NodeStore,
 errors: []const Diagnostic,
 
-/// Returns true if the given region spans multiple lines.
+/// Calculate whether this region is - or will be - multiline
 pub fn regionIsMultiline(self: *IR, region: Region) bool {
     var i = region.start;
     const tags = self.tokens.tokens.items(.tag);
@@ -112,6 +112,10 @@ pub const Diagnostic = struct {
 pub const Region = struct {
     start: TokenIdx,
     end: TokenIdx,
+
+    pub fn spanAcross(self: Region, other: Region) Region {
+        return .{ .start = self.start, .end = other.end };
+    }
 };
 
 /// Unstructured information about a Node.  These
@@ -502,39 +506,26 @@ pub const NodeStore = struct {
     pub fn initWithCapacity(gpa: std.mem.Allocator, capacity: usize) NodeStore {
         var store: NodeStore = .{
             .gpa = gpa,
-            .nodes = .{},
-            .extra_data = .{},
-            .scratch_statements = .{},
-            .scratch_tokens = .{},
-            .scratch_exprs = .{},
-            .scratch_patterns = .{},
-            .scratch_record_fields = .{},
-            .scratch_pattern_record_fields = .{},
-            .scratch_when_branches = .{},
-            .scratch_type_annos = .{},
-            .scratch_anno_record_fields = .{},
-            .scratch_exposed_items = .{},
+            .nodes = Node.List.initCapacity(gpa, capacity),
+            .extra_data = std.ArrayListUnmanaged(u32).initCapacity(gpa, capacity / 2) catch |err| exitOnOom(err),
+            .scratch_statements = std.ArrayListUnmanaged(StatementIdx).initCapacity(gpa, scratch_90th_percentile_capacity) catch |err| exitOnOom(err),
+            .scratch_tokens = std.ArrayListUnmanaged(TokenIdx).initCapacity(gpa, scratch_90th_percentile_capacity) catch |err| exitOnOom(err),
+            .scratch_exprs = std.ArrayListUnmanaged(ExprIdx).initCapacity(gpa, scratch_90th_percentile_capacity) catch |err| exitOnOom(err),
+            .scratch_patterns = std.ArrayListUnmanaged(PatternIdx).initCapacity(gpa, scratch_90th_percentile_capacity) catch |err| exitOnOom(err),
+            .scratch_record_fields = std.ArrayListUnmanaged(RecordFieldIdx).initCapacity(gpa, scratch_90th_percentile_capacity) catch |err| exitOnOom(err),
+            .scratch_pattern_record_fields = std.ArrayListUnmanaged(PatternRecordFieldIdx).initCapacity(gpa, scratch_90th_percentile_capacity) catch |err| exitOnOom(err),
+            .scratch_when_branches = std.ArrayListUnmanaged(WhenBranchIdx).initCapacity(gpa, scratch_90th_percentile_capacity) catch |err| exitOnOom(err),
+            .scratch_type_annos = std.ArrayListUnmanaged(TypeAnnoIdx).initCapacity(gpa, scratch_90th_percentile_capacity) catch |err| exitOnOom(err),
+            .scratch_anno_record_fields = std.ArrayListUnmanaged(AnnoRecordFieldIdx).initCapacity(gpa, scratch_90th_percentile_capacity) catch |err| exitOnOom(err),
+            .scratch_exposed_items = std.ArrayListUnmanaged(ExposedItemIdx).initCapacity(gpa, scratch_90th_percentile_capacity) catch |err| exitOnOom(err),
         };
 
-        store.nodes.ensureTotalCapacity(gpa, capacity);
         _ = store.nodes.append(gpa, .{
             .tag = .root,
             .main_token = 0,
             .data = .{ .lhs = 0, .rhs = 0 },
             .region = .{ .start = 0, .end = 0 },
         });
-        store.extra_data.ensureTotalCapacity(gpa, capacity / 2) catch |err| exitOnOom(err);
-        store.scratch_statements.ensureTotalCapacity(gpa, scratch_90th_percentile_capacity) catch |err| exitOnOom(err);
-        store.scratch_tokens.ensureTotalCapacity(gpa, scratch_90th_percentile_capacity) catch |err| exitOnOom(err);
-        store.scratch_exprs.ensureTotalCapacity(gpa, scratch_90th_percentile_capacity) catch |err| exitOnOom(err);
-        store.scratch_patterns.ensureTotalCapacity(gpa, scratch_90th_percentile_capacity) catch |err| exitOnOom(err);
-        store.scratch_record_fields.ensureTotalCapacity(gpa, scratch_90th_percentile_capacity) catch |err| exitOnOom(err);
-        store.scratch_pattern_record_fields.ensureTotalCapacity(gpa, scratch_90th_percentile_capacity) catch |err| exitOnOom(err);
-        store.scratch_when_branches.ensureTotalCapacity(gpa, scratch_90th_percentile_capacity) catch |err| exitOnOom(err);
-        store.scratch_type_annos.ensureTotalCapacity(gpa, scratch_90th_percentile_capacity) catch |err| exitOnOom(err);
-        store.scratch_anno_record_fields.ensureTotalCapacity(gpa, scratch_90th_percentile_capacity) catch |err| exitOnOom(err);
-        store.scratch_exposed_items.ensureTotalCapacity(gpa, scratch_90th_percentile_capacity) catch |err| exitOnOom(err);
-
         return store;
     }
 
@@ -543,7 +534,7 @@ pub const NodeStore = struct {
     // will only have to be resized in >90th percentile case.
     // It is not scientific, and should be tuned when we have enough
     // Roc code to instrument this and determine a real 90th percentile.
-    const scratch_90th_percentile_capacity = 10;
+    const scratch_90th_percentile_capacity = std.math.ceilPowerOfTwoAssert(usize, 10);
 
     /// Deinitializes all data owned by the store.
     /// A caller should ensure that they have taken
@@ -673,7 +664,7 @@ pub const NodeStore = struct {
                 node.region = mod.region;
             },
             .malformed => {
-                @panic("use addMalformed instead");
+                @panic("Use addMalformed instead");
             },
             else => {},
         }
@@ -804,7 +795,7 @@ pub const NodeStore = struct {
                 node.data.rhs = a.anno.id;
             },
             .malformed => {
-                @panic("use addMalformed instead");
+                @panic("Use addMalformed instead");
             },
         }
         const nid = store.nodes.append(store.gpa, node);
@@ -875,16 +866,14 @@ pub const NodeStore = struct {
                 node.region = u.region;
             },
             .alternatives => |a| {
-                // disabled because it was hit by a fuzz test
-                // for a repro see src/snapshots/fuzz_crash_012.txt
-                // std.debug.assert(a.patterns.span.len > 1);
+                std.debug.assert(a.patterns.span.len > 1);
                 node.region = a.region;
                 node.tag = .alternatives_patt;
                 node.data.lhs = a.patterns.span.start;
                 node.data.rhs = a.patterns.span.len;
             },
             .malformed => {
-                @panic("use addMalformed instead");
+                @panic("Use addMalformed instead");
             },
         }
         const nid = store.nodes.append(store.gpa, node);
@@ -1033,7 +1022,7 @@ pub const NodeStore = struct {
                 node.region = e.region;
             },
             .malformed => {
-                @panic("use addMalformed instead");
+                @panic("Use addMalformed instead");
             },
         }
         const nid = store.nodes.append(store.gpa, node);
@@ -1207,7 +1196,7 @@ pub const NodeStore = struct {
                 node.data.lhs = p.anno.id;
             },
             .malformed => {
-                @panic("use addMalformed instead");
+                @panic("Use addMalformed instead");
             },
         }
 
@@ -1397,6 +1386,12 @@ pub const NodeStore = struct {
                     .anno = .{ .id = node.data.rhs },
                 } };
             },
+            .malformed => {
+                return .{ .malformed = .{
+                    .reason = @enumFromInt(node.data.lhs),
+                    .region = node.region,
+                } };
+            },
             else => {
                 std.debug.panic("Expected a valid statement tag, got {s}", .{@tagName(node.tag)});
             },
@@ -1482,6 +1477,12 @@ pub const NodeStore = struct {
                     .region = node.region,
                 } };
             },
+            .malformed => {
+                return .{ .malformed = .{
+                    .reason = @enumFromInt(node.data.lhs),
+                    .region = node.region,
+                } };
+            },
             else => {
                 std.debug.panic("Expected a valid pattern tag, got {s}", .{@tagName(node.tag)});
             },
@@ -1804,22 +1805,20 @@ pub const NodeStore = struct {
         region: Region,
 
         pub fn toSExpr(self: @This(), env: *base.ModuleEnv, ir: *IR, line_starts: std.ArrayList(u32)) sexpr.Expr {
-            var node = sexpr.Expr.init(env.gpa, "file");
-
-            node.appendRegionChild(env.gpa, ir.regionInfo(self.region, line_starts));
+            var file_node = sexpr.Expr.init(env.gpa, "file");
 
             const header = ir.store.getHeader(self.header);
             var header_node = header.toSExpr(env, ir, line_starts);
 
-            node.appendNodeChild(env.gpa, &header_node);
+            file_node.appendNodeChild(env.gpa, &header_node);
 
             for (ir.store.statementSlice(self.statements)) |stmt_id| {
                 const stmt = ir.store.getStatement(stmt_id);
                 var stmt_node = stmt.toSExpr(env, ir, line_starts);
-                node.appendNodeChild(env.gpa, &stmt_node);
+                file_node.appendNodeChild(env.gpa, &stmt_node);
             }
 
-            return node;
+            return file_node;
         }
     };
 
@@ -1830,19 +1829,17 @@ pub const NodeStore = struct {
         region: Region,
 
         pub fn toSExpr(self: @This(), env: *base.ModuleEnv, ir: *IR, line_starts: std.ArrayList(u32)) sexpr.Expr {
-            var node = sexpr.Expr.init(env.gpa, "block");
-
-            node.appendRegionChild(env.gpa, ir.regionInfo(self.region, line_starts));
+            var block_node = sexpr.Expr.init(env.gpa, "block");
 
             for (ir.store.statementSlice(self.statements)) |stmt_idx| {
                 const stmt = ir.store.getStatement(stmt_idx);
 
                 var stmt_node = stmt.toSExpr(env, ir, line_starts);
 
-                node.appendNodeChild(env.gpa, &stmt_node);
+                block_node.appendNodeChild(env.gpa, &stmt_node);
             }
 
-            return node;
+            return block_node;
         }
     };
 
@@ -1942,12 +1939,11 @@ pub const NodeStore = struct {
         },
 
         pub fn toSExpr(self: @This(), env: *base.ModuleEnv, ir: *IR, line_starts: std.ArrayList(u32)) sexpr.Expr {
+            _ = line_starts;
             var node = sexpr.Expr.init(env.gpa, "exposed_item");
             var inner_node = sexpr.Expr.init(env.gpa, @tagName(self));
-
             switch (self) {
                 .lower_ident => |i| {
-                    node.appendRegionChild(env.gpa, ir.regionInfo(i.region, line_starts));
                     const token = ir.tokens.tokens.get(i.ident);
                     const text = env.idents.getText(token.extra.interned);
                     inner_node.appendStringChild(env.gpa, text);
@@ -1958,7 +1954,6 @@ pub const NodeStore = struct {
                     }
                 },
                 .upper_ident => |i| {
-                    node.appendRegionChild(env.gpa, ir.regionInfo(i.region, line_starts));
                     const token = ir.tokens.tokens.get(i.ident);
                     const text = env.idents.getText(token.extra.interned);
                     inner_node.appendStringChild(env.gpa, text);
@@ -1969,7 +1964,6 @@ pub const NodeStore = struct {
                     }
                 },
                 .upper_ident_star => |i| {
-                    node.appendRegionChild(env.gpa, ir.regionInfo(i.region, line_starts));
                     const token = ir.tokens.tokens.get(i.ident);
                     const text = env.idents.getText(token.extra.interned);
                     inner_node.appendStringChild(env.gpa, text);

src/check/parse/Parser.zig

@@ -58,7 +58,7 @@ fn test_parser(source: []const u8, run: fn (parser: Parser) TestError!void) Test
 
 /// helper to advance the parser until a non-newline token is encountered
 pub fn advance(self: *Parser) void {
-    while (true) {
+    while (true and self.peek() != .EndOfFile) {
         self.pos += 1;
         if (self.peek() != .Newline) {
             break;
@@ -101,12 +101,17 @@ pub fn peekLast(self: Parser) ?Token.Tag {
 }
 /// peek at the next available token
 pub fn peekNext(self: Parser) Token.Tag {
-    const next = self.pos + 1;
+    var next = self.pos + 1;
+    const tags = self.tok_buf.tokens.items(.tag);
+    while (next < self.tok_buf.tokens.len and tags[next] == .Newline) {
+        next += 1;
+    }
     if (next >= self.tok_buf.tokens.len) {
         return .EndOfFile;
     }
-    return self.tok_buf.tokens.items(.tag)[next];
+    return tags[next];
 }
+
 /// add a diagnostic error
 pub fn pushDiagnostic(self: *Parser, tag: IR.Diagnostic.Tag, region: IR.Region) void {
     self.diagnostics.append(self.gpa, .{
@@ -144,6 +149,10 @@ pub fn parseFile(self: *Parser) void {
         .region = .{ .start = 0, .end = 0 },
     });
 
+    while (self.peek() == .Newline) {
+        self.advanceOne();
+    }
+
     const header = self.parseHeader();
     const scratch_top = self.store.scratchStatementTop();
 
@@ -315,6 +324,8 @@ pub fn parseAppHeader(self: *Parser) IR.NodeStore.HeaderIdx {
         self.store.clearScratchRecordFieldsFrom(fields_scratch_top);
         return self.pushMalformed(IR.NodeStore.HeaderIdx, .expected_package_platform_close_curly, start);
     }
+    self.advanceOne(); // Advance past CloseCurly
+    const end = self.pos;
     const packages = self.store.recordFieldSpanFrom(fields_scratch_top);
     self.advance();
 
@@ -326,7 +337,7 @@ pub fn parseAppHeader(self: *Parser) IR.NodeStore.HeaderIdx {
                     .platform_name = pn,
                     .provides = provides,
                     .packages = packages,
-                    .region = .{ .start = 0, .end = 0 },
+                    .region = .{ .start = start, .end = end },
                 },
             };
             const idx = self.store.addHeader(header);
@@ -410,13 +421,15 @@ pub fn parseStmt(self: *Parser) ?IR.NodeStore.StatementIdx {
                 qualifier = self.pos;
                 self.advance(); // Advance past LowerIdent
             }
-            if (self.peek() == .UpperIdent or (qualifier != null and self.peek() == .NoSpaceDotUpperIdent)) {
+            if (self.peek() == .UpperIdent or (qualifier != null and (self.peek() == .NoSpaceDotUpperIdent or self.peek() == .DotUpperIdent))) {
                 var exposes: IR.NodeStore.ExposedItemSpan = .{ .span = .{ .start = 0, .len = 0 } };
                 const module_name_tok = self.pos;
+                var end = self.pos;
                 if (self.peekNext() == .KwAs) {
                     self.advance(); // Advance past UpperIdent
                     self.advance(); // Advance past KwAs
                     alias_tok = self.pos;
+                    end = self.pos;
                     self.expect(.UpperIdent) catch {
                         const malformed = self.pushMalformed(IR.NodeStore.StatementIdx, .unexpected_token, start);
                         self.advance();
@@ -429,7 +442,7 @@ pub fn parseStmt(self: *Parser) ?IR.NodeStore.StatementIdx {
                         return self.pushMalformed(IR.NodeStore.StatementIdx, .import_exposing_no_open, start);
                     };
                     const scratch_top = self.store.scratchExposedItemTop();
-                    _ = self.parseCollectionSpan(IR.NodeStore.ExposedItemIdx, .CloseSquare, IR.NodeStore.addScratchExposedItem, Parser.parseExposedItem) catch {
+                    end = self.parseCollectionSpan(IR.NodeStore.ExposedItemIdx, .CloseSquare, IR.NodeStore.addScratchExposedItem, Parser.parseExposedItem) catch {
                         while (self.peek() != .CloseSquare and self.peek() != .EndOfFile) {
                             self.advance();
                         }
@@ -446,7 +459,7 @@ pub fn parseStmt(self: *Parser) ?IR.NodeStore.StatementIdx {
                     .qualifier_tok = qualifier,
                     .alias_tok = alias_tok,
                     .exposes = exposes,
-                    .region = .{ .start = start, .end = self.pos },
+                    .region = .{ .start = start, .end = end },
                 } });
                 if (self.peek() == .Newline) {
                     self.advance();
@@ -503,20 +516,16 @@ pub fn parseStmt(self: *Parser) ?IR.NodeStore.StatementIdx {
                 self.advance(); // Advance past LowerIdent
                 self.advance(); // Advance past OpAssign
                 const idx = self.parseExpr();
+                const expr_region = self.store.nodes.items.items(.region)[idx.id];
                 const patt_idx = self.store.addPattern(.{ .ident = .{
                     .ident_tok = start,
                     .region = .{ .start = start, .end = start },
                 } });
-                const statement_idx = self.store.addStatement(.{
-                    .decl = .{
-                        .pattern = patt_idx,
-                        .body = idx,
-                        .region = .{
-                            .start = start,
-                            .end = self.pos - 1, // we want the end of the previous token
-                        },
-                    },
-                });
+                const statement_idx = self.store.addStatement(.{ .decl = .{
+                    .pattern = patt_idx,
+                    .body = idx,
+                    .region = .{ .start = start, .end = expr_region.end },
+                } });
                 if (self.peek() == .Newline) {
                     self.advance();
                 }
@@ -609,7 +618,7 @@ pub fn parsePattern(self: *Parser, alternatives: Alternatives) IR.NodeStore.Patt
                     self.advance(); // Advance past NoSpaceOpenRound
                     // Parse args
                     const scratch_top = self.store.scratchPatternTop();
-                    _ = self.parseCollectionSpan(IR.NodeStore.PatternIdx, .CloseRound, IR.NodeStore.addScratchPattern, parsePatternWithAlts) catch {
+                    const args_end = self.parseCollectionSpan(IR.NodeStore.PatternIdx, .CloseRound, IR.NodeStore.addScratchPattern, parsePatternWithAlts) catch {
                         while (self.peek() != .CloseRound and self.peek() != .EndOfFile) {
                             self.advance();
                         }
@@ -618,7 +627,7 @@ pub fn parsePattern(self: *Parser, alternatives: Alternatives) IR.NodeStore.Patt
                     };
                     const args = self.store.patternSpanFrom(scratch_top);
                     pattern = self.store.addPattern(.{ .tag = .{
-                        .region = .{ .start = start, .end = self.pos },
+                        .region = .{ .start = start, .end = args_end },
                         .args = args,
                         .tag_tok = start,
                     } });
@@ -647,7 +656,7 @@ pub fn parsePattern(self: *Parser, alternatives: Alternatives) IR.NodeStore.Patt
                 // List
                 self.advance();
                 const scratch_top = self.store.scratchPatternTop();
-                _ = self.parseCollectionSpan(IR.NodeStore.PatternIdx, .CloseSquare, IR.NodeStore.addScratchPattern, parsePatternWithAlts) catch {
+                const end = self.parseCollectionSpan(IR.NodeStore.PatternIdx, .CloseSquare, IR.NodeStore.addScratchPattern, parsePatternWithAlts) catch {
                     while (self.peek() != .CloseSquare and self.peek() != .EndOfFile) {
                         self.advance();
                     }
@@ -657,7 +666,7 @@ pub fn parsePattern(self: *Parser, alternatives: Alternatives) IR.NodeStore.Patt
                 const patterns = self.store.patternSpanFrom(scratch_top);
 
                 pattern = self.store.addPattern(.{ .list = .{
-                    .region = .{ .start = start, .end = self.pos },
+                    .region = .{ .start = start, .end = end },
                     .patterns = patterns,
                 } });
             },
@@ -675,9 +684,10 @@ pub fn parsePattern(self: *Parser, alternatives: Alternatives) IR.NodeStore.Patt
                 if (self.peek() != .CloseCurly) {
                     return self.pushMalformed(IR.NodeStore.PatternIdx, .pattern_unexpected_token, start);
                 }
+                const end = self.pos;
                 self.advance();
                 pattern = self.store.addPattern(.{ .record = .{
-                    .region = .{ .start = start, .end = self.pos },
+                    .region = .{ .start = start, .end = end },
                     .fields = fields,
                 } });
             },
@@ -708,7 +718,7 @@ pub fn parsePattern(self: *Parser, alternatives: Alternatives) IR.NodeStore.Patt
             .OpenRound, .NoSpaceOpenRound => {
                 self.advance();
                 const scratch_top = self.store.scratchPatternTop();
-                _ = self.parseCollectionSpan(IR.NodeStore.PatternIdx, .CloseRound, IR.NodeStore.addScratchPattern, parsePatternWithAlts) catch {
+                const end = self.parseCollectionSpan(IR.NodeStore.PatternIdx, .CloseRound, IR.NodeStore.addScratchPattern, parsePatternWithAlts) catch {
                     while (self.peek() != .CloseRound and self.peek() != .EndOfFile) {
                         self.advance();
                     }
@@ -719,7 +729,7 @@ pub fn parsePattern(self: *Parser, alternatives: Alternatives) IR.NodeStore.Patt
 
                 pattern = self.store.addPattern(.{ .tuple = .{
                     .patterns = patterns,
-                    .region = .{ .start = start, .end = self.pos },
+                    .region = .{ .start = start, .end = end },
                 } });
             },
             else => {
@@ -745,9 +755,11 @@ pub fn parsePattern(self: *Parser, alternatives: Alternatives) IR.NodeStore.Patt
     if ((self.store.scratchPatternTop() - patterns_scratch_top) == 0) {
         std.debug.panic("Should have gotten a valid pattern, pos={d} peek={s}\n", .{ self.pos, @tagName(self.peek()) });
     }
+    const last_pattern = self.store.scratch_patterns.items[self.store.scratchPatternTop() - 1];
+    const last_pattern_region = self.store.nodes.items.items(.region)[last_pattern.id];
     const patterns = self.store.patternSpanFrom(patterns_scratch_top);
     return self.store.addPattern(.{ .alternatives = .{
-        .region = .{ .start = outer_start, .end = self.pos },
+        .region = .{ .start = outer_start, .end = last_pattern_region.end },
         .patterns = patterns,
     } });
 }
@@ -886,7 +898,7 @@ pub fn parseExprWithBp(self: *Parser, min_bp: u8) IR.NodeStore.ExprIdx {
             self.advance();
             // TODO: Parenthesized expressions
             const scratch_top = self.store.scratchExprTop();
-            _ = self.parseCollectionSpan(IR.NodeStore.ExprIdx, .CloseRound, IR.NodeStore.addScratchExpr, parseExpr) catch {
+            const end = self.parseCollectionSpan(IR.NodeStore.ExprIdx, .CloseRound, IR.NodeStore.addScratchExpr, parseExpr) catch {
                 while (self.peek() != .CloseRound and self.peek() != .EndOfFile) {
                     self.advance();
                 }
@@ -896,7 +908,7 @@ pub fn parseExprWithBp(self: *Parser, min_bp: u8) IR.NodeStore.ExprIdx {
             const items = self.store.exprSpanFrom(scratch_top);
             expr = self.store.addExpr(.{ .tuple = .{
                 .items = items,
-                .region = .{ .start = start, .end = self.pos },
+                .region = .{ .start = start, .end = end },
             } });
         },
         .OpenCurly => {
@@ -906,21 +918,23 @@ pub fn parseExprWithBp(self: *Parser, min_bp: u8) IR.NodeStore.ExprIdx {
                 // This is the best guesstimation of this being a Record for now.  I believe we have to have a NoSpaceOpColon
                 // for this to be full-proof without backtracking.
                 const scratch_top = self.store.scratchRecordFieldTop();
-                _ = self.parseCollectionSpan(IR.NodeStore.RecordFieldIdx, .CloseCurly, IR.NodeStore.addScratchRecordField, parseRecordField) catch {
+                const end = self.parseCollectionSpan(IR.NodeStore.RecordFieldIdx, .CloseCurly, IR.NodeStore.addScratchRecordField, parseRecordField) catch {
                     self.store.clearScratchRecordFieldsFrom(scratch_top);
                     return self.pushMalformed(IR.NodeStore.ExprIdx, .unexpected_token, start);
                 };
                 const fields = self.store.recordFieldSpanFrom(scratch_top);
                 expr = self.store.addExpr(.{ .record = .{
                     .fields = fields,
-                    .region = .{ .start = start, .end = self.pos },
+                    .region = .{ .start = start, .end = end },
                 } });
             } else {
                 const scratch_top = self.store.scratchStatementTop();
+                var end = self.pos;
 
                 while (self.peek() != .EndOfFile) {
                     const statement = self.parseStmt() orelse break;
                     self.store.addScratchStatement(statement);
+                    end = self.pos;
                     if (self.peek() == .CloseCurly) {
                         self.advance();
                         break;
@@ -931,7 +945,7 @@ pub fn parseExprWithBp(self: *Parser, min_bp: u8) IR.NodeStore.ExprIdx {
 
                 expr = self.store.addExpr(.{ .block = .{
                     .statements = statements,
-                    .region = .{ .start = start, .end = self.pos },
+                    .region = .{ .start = start, .end = end },
                 } });
             }
         },
@@ -945,10 +959,11 @@ pub fn parseExprWithBp(self: *Parser, min_bp: u8) IR.NodeStore.ExprIdx {
             const args = self.store.patternSpanFrom(scratch_top);
 
             const body = self.parseExpr();
+            const body_region = self.store.nodes.items.items(.region)[body.id];
             expr = self.store.addExpr(.{ .lambda = .{
                 .body = body,
                 .args = args,
-                .region = .{ .start = start, .end = self.pos },
+                .region = .{ .start = start, .end = body_region.end },
             } });
         },
         .KwIf => {
@@ -1012,7 +1027,7 @@ pub fn parseExprWithBp(self: *Parser, min_bp: u8) IR.NodeStore.ExprIdx {
     }
     if (expr) |e| {
         var expression = self.parseExprSuffix(start, e);
-        while (self.peek() == .NoSpaceDotInt or self.peek() == .NoSpaceDotLowerIdent) {
+        while (self.peek() == .NoSpaceDotInt or self.peek() == .NoSpaceDotLowerIdent or self.peek() == .DotLowerIdent) {
             const tok = self.peek();
             if (tok == .NoSpaceDotInt) {
                 return self.pushMalformed(IR.NodeStore.ExprIdx, .expr_no_space_dot_int, self.pos);
@@ -1062,7 +1077,7 @@ fn parseExprSuffix(self: *Parser, start: u32, e: IR.NodeStore.ExprIdx) IR.NodeSt
     if (self.peek() == .NoSpaceOpenRound) {
         self.advance();
         const scratch_top = self.store.scratchExprTop();
-        _ = self.parseCollectionSpan(IR.NodeStore.ExprIdx, .CloseRound, IR.NodeStore.addScratchExpr, parseExpr) catch {
+        const end = self.parseCollectionSpan(IR.NodeStore.ExprIdx, .CloseRound, IR.NodeStore.addScratchExpr, parseExpr) catch {
             self.store.clearScratchExprsFrom(scratch_top);
             return self.pushMalformed(IR.NodeStore.ExprIdx, .unexpected_token, start);
         };
@@ -1071,7 +1086,7 @@ fn parseExprSuffix(self: *Parser, start: u32, e: IR.NodeStore.ExprIdx) IR.NodeSt
         expression = self.store.addExpr(.{ .apply = .{
             .args = args,
             .@"fn" = e,
-            .region = .{ .start = start, .end = self.pos },
+            .region = .{ .start = start, .end = end },
         } });
     }
     if (self.peek() == .NoSpaceOpQuestion) {
@@ -1131,8 +1146,10 @@ pub fn parseStringExpr(self: *Parser) IR.NodeStore.ExprIdx {
     self.advanceOne();
     const scratch_top = self.store.scratchExprTop();
     while (self.peek() != .EndOfFile) {
+        var string_end = self.pos;
         switch (self.peek()) {
             .StringEnd => {
+                string_end = self.pos;
                 self.advanceOne();
                 break;
             },
@@ -1145,11 +1162,14 @@ pub fn parseStringExpr(self: *Parser) IR.NodeStore.ExprIdx {
                 self.store.addScratchExpr(index);
             },
             .OpenStringInterpolation => {
-                self.advanceOne();
+                self.advance();
                 const ex = self.parseExpr();
                 self.store.addScratchExpr(ex);
+                while (self.peek() == .Newline) {
+                    self.advanceOne();
+                }
                 if (self.peek() != .CloseStringInterpolation) {
-                    return self.pushMalformed(IR.NodeStore.ExprIdx, .string_expected_close_interpolation, self.pos);
+                    return self.pushMalformed(IR.NodeStore.ExprIdx, .string_expected_close_interpolation, start);
                 }
                 self.advanceOne();
             },
@@ -1201,15 +1221,17 @@ pub fn parseTypeHeader(self: *Parser) IR.NodeStore.TypeHeaderIdx {
         });
     }
     const scratch_top = self.store.scratchTokenTop();
+    var end = self.pos;
     while (self.peek() == .LowerIdent) {
         self.store.addScratchToken(self.pos);
+        end = self.pos;
         self.advance(); // Advance past LowerIdent
     }
     const args = self.store.tokenSpanFrom(scratch_top);
     return self.store.addTypeHeader(.{
         .name = start,
         .args = args,
-        .region = .{ .start = start, .end = self.pos },
+        .region = .{ .start = start, .end = end },
     });
 }
 
@@ -1228,10 +1250,12 @@ pub fn parseTypeAnno(self: *Parser, looking_for_args: TyFnArgs) IR.NodeStore.Typ
             if (self.peekNext() != .NoSpaceOpenRound) {
                 anno = self.store.addTypeAnno(.{ .tag = .{
                     .tok = self.pos,
-                    .args = .{ .span = .{
-                        .start = 0,
-                        .len = 0,
-                    } },
+                    .args = .{
+                        .span = .{
+                            .start = 0,
+                            .len = 0,
+                        },
+                    },
                     .region = .{ .start = start, .end = self.pos },
                 } });
                 self.advance(); // Advance past UpperIdent
@@ -1239,13 +1263,13 @@ pub fn parseTypeAnno(self: *Parser, looking_for_args: TyFnArgs) IR.NodeStore.Typ
                 self.advance(); // Advance past UpperIdent
                 self.advance(); // Advance past NoSpaceOpenRound
                 const scratch_top = self.store.scratchTypeAnnoTop();
-                _ = self.parseCollectionSpan(IR.NodeStore.TypeAnnoIdx, .CloseRound, IR.NodeStore.addScratchTypeAnno, parseTypeAnnoInCollection) catch {
+                const end = self.parseCollectionSpan(IR.NodeStore.TypeAnnoIdx, .CloseRound, IR.NodeStore.addScratchTypeAnno, parseTypeAnnoInCollection) catch {
                     self.store.clearScratchTypeAnnosFrom(scratch_top);
                     return self.pushMalformed(IR.NodeStore.TypeAnnoIdx, .unexpected_token, start);
                 };
                 const args = self.store.typeAnnoSpanFrom(scratch_top);
                 anno = self.store.addTypeAnno(.{ .tag = .{
-                    .region = .{ .start = start, .end = self.pos },
+                    .region = .{ .start = start, .end = end },
                     .tok = start,
                     .args = args,
                 } });
@@ -1277,6 +1301,7 @@ pub fn parseTypeAnno(self: *Parser, looking_for_args: TyFnArgs) IR.NodeStore.Typ
                 const args = self.store.typeAnnoSpanFrom(scratch_top);
                 self.advance();
                 const ret = self.parseTypeAnno(.not_looking_for_args);
+                const ret_region = self.store.nodes.items.items(.region)[ret.id];
                 if (self.peek() != .CloseRound) {
                     self.store.clearScratchTypeAnnosFrom(scratch_top);
                     return self.pushMalformed(IR.NodeStore.TypeAnnoIdx, .unexpected_token, start);
@@ -1284,48 +1309,50 @@ pub fn parseTypeAnno(self: *Parser, looking_for_args: TyFnArgs) IR.NodeStore.Typ
                 const function = self.store.addTypeAnno(.{ .@"fn" = .{
                     .args = args,
                     .ret = ret,
-                    .region = .{ .start = after_round, .end = self.pos },
+                    .region = .{ .start = after_round, .end = ret_region.end },
                 } });
+                const end = self.pos;
                 self.advance();
                 return self.store.addTypeAnno(.{ .parens = .{
                     .anno = function,
-                    .region = .{ .start = start, .end = self.pos },
+                    .region = .{ .start = start, .end = end },
                 } });
             }
             if (self.peek() != .CloseRound) {
                 self.store.clearScratchTypeAnnosFrom(scratch_top);
                 return self.pushMalformed(IR.NodeStore.TypeAnnoIdx, .unexpected_token, start);
             }
+            const end = self.pos;
             self.advance(); // Advance past CloseRound
             const annos = self.store.typeAnnoSpanFrom(scratch_top);
             anno = self.store.addTypeAnno(.{ .tuple = .{
-                .region = .{ .start = start, .end = self.pos },
+                .region = .{ .start = start, .end = end },
                 .annos = annos,
             } });
         },
         .OpenCurly => {
             self.advance(); // Advance past OpenCurly
             const scratch_top = self.store.scratchAnnoRecordFieldTop();
-            _ = self.parseCollectionSpan(IR.NodeStore.AnnoRecordFieldIdx, .CloseCurly, IR.NodeStore.addScratchAnnoRecordField, parseAnnoRecordField) catch {
+            const end = self.parseCollectionSpan(IR.NodeStore.AnnoRecordFieldIdx, .CloseCurly, IR.NodeStore.addScratchAnnoRecordField, parseAnnoRecordField) catch {
                 self.store.clearScratchAnnoRecordFieldsFrom(scratch_top);
                 return self.pushMalformed(IR.NodeStore.TypeAnnoIdx, .unexpected_token, start);
             };
             const fields = self.store.annoRecordFieldSpanFrom(scratch_top);
             anno = self.store.addTypeAnno(.{ .record = .{
-                .region = .{ .start = start, .end = self.pos },
+                .region = .{ .start = start, .end = end },
                 .fields = fields,
             } });
         },
         .OpenSquare => {
             self.advance(); // Advance past OpenSquare
             const scratch_top = self.store.scratchTypeAnnoTop();
-            _ = self.parseCollectionSpan(IR.NodeStore.TypeAnnoIdx, .CloseSquare, IR.NodeStore.addScratchTypeAnno, parseTypeAnnoInCollection) catch {
+            const end = self.parseCollectionSpan(IR.NodeStore.TypeAnnoIdx, .CloseSquare, IR.NodeStore.addScratchTypeAnno, parseTypeAnnoInCollection) catch {
                 self.store.clearScratchTypeAnnosFrom(scratch_top);
                 return self.pushMalformed(IR.NodeStore.TypeAnnoIdx, .unexpected_token, start);
             };
             const tags = self.store.typeAnnoSpanFrom(scratch_top);
             anno = self.store.addTypeAnno(.{ .tag_union = .{
-                .region = .{ .start = start, .end = self.pos },
+                .region = .{ .start = start, .end = end },
                 .open_anno = null,
                 .tags = tags,
             } });
@@ -1356,8 +1383,9 @@ pub fn parseTypeAnno(self: *Parser, looking_for_args: TyFnArgs) IR.NodeStore.Typ
             self.advance(); // Advance past arrow
             // TODO: Handle thin vs fat arrow
             const ret = self.parseTypeAnno(.not_looking_for_args);
+            const region = self.store.nodes.items.items(.region)[ret.id];
             return self.store.addTypeAnno(.{ .@"fn" = .{
-                .region = .{ .start = start, .end = self.pos },
+                .region = .{ .start = start, .end = region.end },
                 .args = args,
                 .ret = ret,
             } });

src/check/parse/tokenize.zig

@@ -361,9 +361,11 @@ pub const TokenizedBuffer = struct {
     tokens: Token.List,
     env: *base.ModuleEnv,
 
-    pub fn init(env: *base.ModuleEnv) TokenizedBuffer {
+    pub fn initCapacity(env: *base.ModuleEnv, capacity: usize) TokenizedBuffer {
+        var tokens = Token.List{};
+        tokens.ensureTotalCapacity(env.gpa, capacity) catch |err| exitOnOom(err);
         return TokenizedBuffer{
-            .tokens = Token.List{},
+            .tokens = tokens,
             .env = env,
         };
     }
@@ -404,12 +406,17 @@ pub const TokenizedBuffer = struct {
         }) catch |err| exitOnOom(err);
     }
 
-    pub fn pushNewline(self: *TokenizedBuffer, indent: u32) void {
-        self.tokens.append(self.env.gpa, .{
+    pub fn pushNewline(self: *TokenizedBuffer, comment: ?Comment) void {
+        var token = Token{
             .tag = .Newline,
-            .offset = indent, // store the indent in the offset field
+            .offset = 0, // store the Comment start - if it is exists here
             .extra = .{ .length = 0 },
-        }) catch |err| exitOnOom(err);
+        };
+        if (comment) |c| {
+            token.offset = c.begin;
+            token.extra = .{ .length = if (c.end > c.begin) c.end - c.begin else 0 };
+        }
+        self.tokens.append(self.env.gpa, token) catch |err| exitOnOom(err);
     }
 
     /// Returns the offset of the token at index `idx`.
@@ -522,6 +529,7 @@ pub const Cursor = struct {
     messages: []Diagnostic,
     message_count: u32,
     tab_width: u8 = 4, // TODO: make this configurable
+    comment: ?Comment = null,
 
     /// Initialize a Cursor with the given input buffer and a pre-allocated messages slice.
     pub fn init(buf: []const u8, messages: []Diagnostic) Cursor {
@@ -582,6 +590,14 @@ pub const Cursor = struct {
         }
     }
 
+    pub fn popComment(self: *Cursor) ?Comment {
+        if (self.comment) |c| {
+            self.comment = null;
+            return c;
+        }
+        return null;
+    }
+
     /// Chomps “trivia” (whitespace, comments, etc.) and returns an optional indent.
     /// If the chomped trivia includes a newline, returns the indent of the next (real) line.
     /// Otherwise, returns null.
@@ -604,20 +620,24 @@ pub const Cursor = struct {
                 self.pos += 1;
                 sawNewline = true;
                 indent = 0;
+                return indent;
             } else if (b == '\r') {
                 self.pos += 1;
                 sawNewline = true;
                 indent = 0;
                 if (self.pos < self.buf.len and self.buf[self.pos] == '\n') {
                     self.pos += 1;
+                    return indent;
                 } else {
                     self.pushMessageHere(.MisplacedCarriageReturn);
                 }
             } else if (b == '#') {
                 self.pos += 1;
+                const comment_start = self.pos;
                 while (self.pos < self.buf.len and self.buf[self.pos] != '\n' and self.buf[self.pos] != '\r') {
                     self.pos += 1;
                 }
+                self.comment = Comment{ .begin = comment_start, .end = self.pos };
             } else if (b >= 0 and b <= 31) {
                 self.pushMessageHere(.AsciiControl);
                 self.pos += 1;
@@ -625,9 +645,6 @@ pub const Cursor = struct {
                 break;
             }
         }
-        if (sawNewline) {
-            return indent;
-        }
         return null;
     }
 
@@ -988,7 +1005,9 @@ pub const Tokenizer = struct {
     /// Note that the caller must also provide a pre-allocated messages buffer.
     pub fn init(env: *base.ModuleEnv, text: []const u8, messages: []Diagnostic) Tokenizer {
         const cursor = Cursor.init(text, messages);
-        const output = TokenizedBuffer.init(env);
+        // TODO: tune this more. Syntax grab bag is 3:1.
+        // Generally, roc code will be less dense than that.
+        const output = TokenizedBuffer.initCapacity(env, @max(text.len / 8, 64));
         return Tokenizer{
             .cursor = cursor,
             .output = output,
@@ -1086,8 +1105,8 @@ pub const Tokenizer = struct {
             switch (b) {
                 // Whitespace & control characters
                 0...32, '#' => {
-                    if (self.cursor.chompTrivia()) |indent| {
-                        self.output.pushNewline(indent);
+                    if (self.cursor.chompTrivia()) |_| {
+                        self.output.pushNewline(self.cursor.popComment());
                     }
                     sawWhitespace = true;
                 },

src/collections/SmallStringInterner.zig

@@ -29,6 +29,21 @@ regions: std.ArrayListUnmanaged(Region) = .{},
 /// A unique index for a deduped string in this interner.
 pub const Idx = enum(u32) { _ };
 
+/// Intiailize a `SmallStringInterner` with the specified capacity.
+pub fn initCapacity(gpa: std.mem.Allocator, capacity: usize) Self {
+    // TODO: tune this. Rough assumption that average small string is 4 bytes.
+    const bytes_per_string = 4;
+
+    var self = Self{
+        .bytes = std.ArrayListUnmanaged(u8).initCapacity(gpa, capacity * bytes_per_string) catch |err| exitOnOom(err),
+        .strings = .{},
+        .outer_indices = std.ArrayListUnmanaged(StringIdx).initCapacity(gpa, capacity) catch |err| exitOnOom(err),
+        .regions = std.ArrayListUnmanaged(Region).initCapacity(gpa, capacity) catch |err| exitOnOom(err),
+    };
+    self.strings.ensureTotalCapacityContext(gpa, @intCast(capacity), StringIdx.TableContext{ .bytes = &self.bytes }) catch |err| exitOnOom(err);
+    return self;
+}
+
 /// Free all memory consumed by this interner.
 /// Will invalidate all slices referencing the interner.
 pub fn deinit(self: *Self, gpa: std.mem.Allocator) void {

src/collections/safe_list.zig

@@ -49,6 +49,13 @@ pub fn SafeList(comptime T: type) type {
             }
         };
 
+        /// Intialize the `SafeList` with the specified capacity.
+        pub fn initCapacity(gpa: Allocator, capacity: usize) SafeList(T) {
+            return .{
+                .items = std.ArrayListUnmanaged(T).initCapacity(gpa, capacity) catch |err| exitOnOom(err),
+            };
+        }
+
         /// Deinitialize the memory of this `SafeList`.
         pub fn deinit(self: *SafeList(T), gpa: Allocator) void {
             self.items.deinit(gpa);
@@ -163,6 +170,15 @@ pub fn SafeMultiList(comptime T: type) type {
             return self.items.items(field_name)[@as(usize, @intFromEnum(idx))];
         }
 
+        /// Intialize the `SafeMultiList` with the specified capacity.
+        pub fn initCapacity(gpa: Allocator, capacity: usize) SafeMultiList(T) {
+            var items = std.MultiArrayList(T){};
+            items.ensureTotalCapacity(gpa, capacity) catch |err| exitOnOom(err);
+            return .{
+                .items = items,
+            };
+        }
+
         /// Deinitialize the memory of a `SafeMultiList`.
         pub fn deinit(self: *SafeMultiList(T), gpa: Allocator) void {
             self.items.deinit(gpa);

src/collections/utils.zig

@@ -1,4 +1,5 @@
 const std = @import("std");
+const tracy = @import("../tracy.zig");
 
 /// Exit the current process when we hit an out-of-memory error.
 ///
@@ -21,5 +22,8 @@ pub fn exitOnOom(err: std.mem.Allocator.Error) noreturn {
 /// Log a fatal error and exit the process with a non-zero code.
 pub fn fatal(comptime format: []const u8, args: anytype) noreturn {
     std.io.getStdErr().writer().print(format, args) catch unreachable;
+    if (tracy.enable) {
+        tracy.waitForShutdown() catch unreachable;
+    }
     std.process.exit(1);
 }

src/main.zig

@@ -39,20 +39,28 @@ const usage =
 
 /// The CLI entrypoint for the Roc compiler.
 pub fn main() !void {
-    const gpa = std.heap.c_allocator;
-
-    const args = try std.process.argsAlloc(gpa);
-    defer gpa.free(args);
+    var gpa_tracy: tracy.TracyAllocator(null) = undefined;
+    var gpa = std.heap.c_allocator;
 
     if (tracy.enable_allocation) {
-        var gpa_tracy = tracy.tracyAllocator(gpa);
-        return mainArgs(gpa_tracy.allocator(), args);
+        gpa_tracy = tracy.tracyAllocator(gpa);
+        gpa = gpa_tracy.allocator();
     }
 
-    return mainArgs(gpa, args);
+    var arena_impl = std.heap.ArenaAllocator.init(gpa);
+    defer arena_impl.deinit();
+    const arena = arena_impl.allocator();
+
+    const args = try std.process.argsAlloc(arena);
+
+    const result = mainArgs(gpa, arena, args);
+    if (tracy.enable) {
+        try tracy.waitForShutdown();
+    }
+    return result;
 }
 
-fn mainArgs(gpa: Allocator, args: []const []const u8) !void {
+fn mainArgs(gpa: Allocator, arena: Allocator, args: []const []const u8) !void {
     const trace = tracy.trace(@src());
     defer trace.end();
 
@@ -74,7 +82,7 @@ fn mainArgs(gpa: Allocator, args: []const []const u8) !void {
             .roc_build => try rocBuild(gpa, opt, cmd_args),
             .roc_test => try rocTest(gpa, opt, cmd_args),
             .roc_repl => try rocRepl(gpa, opt, cmd_args),
-            .roc_format => try rocFormat(gpa, cmd_args),
+            .roc_format => try rocFormat(gpa, arena, cmd_args),
             .roc_version => try rocVersion(gpa, cmd_args),
             .roc_check => rocCheck(gpa, opt, cmd_args),
             .roc_docs => try rocDocs(gpa, opt, cmd_args),
@@ -130,19 +138,24 @@ fn rocRepl(gpa: Allocator, opt: RocOpt, args: []const []const u8) !void {
 
 /// Reads, parses, formats, and overwrites all Roc files at the given paths.
 /// Recurses into directories to search for Roc files.
-fn rocFormat(gpa: Allocator, args: []const []const u8) !void {
+fn rocFormat(gpa: Allocator, arena: Allocator, args: []const []const u8) !void {
     var timer = try std.time.Timer.start();
-    var count: usize = 0;
+    var count = fmt.SuccessFailCount{ .success = 0, .failure = 0 };
     if (args.len > 0) {
         for (args) |arg| {
-            count += try fmt.formatPath(gpa, std.fs.cwd(), arg);
+            const inner_count = try fmt.formatPath(gpa, arena, std.fs.cwd(), arg);
+            count.success += inner_count.success;
+            count.failure += inner_count.failure;
         }
     } else {
-        count = try fmt.formatPath(gpa, std.fs.cwd(), "main.roc");
+        count = try fmt.formatPath(gpa, arena, std.fs.cwd(), "main.roc");
     }
-
     const elapsed = timer.read() / std.time.ns_per_ms;
-    try std.io.getStdOut().writer().print("Successfully formatted {} files in {} ms.\n", .{ count, elapsed });
+    try std.io.getStdOut().writer().print("Successfully formatted {} files\n", .{count.success});
+    if (count.failure > 0) {
+        try std.io.getStdOut().writer().print("Failed to format {} files.\n", .{count.failure});
+    }
+    try std.io.getStdOut().writer().print("Took {} ms.\n", .{elapsed});
 }
 
 fn rocVersion(gpa: Allocator, args: []const []const u8) !void {

src/snapshots/001.txt

@@ -12,20 +12,27 @@ foo =
 ~~~PROBLEMS
 NIL
 ~~~TOKENS
-KwModule(1:1-1:7),OpenSquare(1:12-1:13),Newline(1:2-1:2),
-LowerIdent(3:2-3:5),Comma(3:5-3:6),Newline(1:6-1:6),
+KwModule(1:1-1:7),OpenSquare(1:12-1:13),Newline(1:1-1:1),
+Newline(2:2-2:24),
+LowerIdent(3:2-3:5),Comma(3:5-3:6),Newline(1:1-1:1),
 CloseSquare(4:6-4:7),Newline(1:1-1:1),
-LowerIdent(6:1-6:4),OpAssign(6:5-6:6),Newline(1:5-1:5),
+Newline(1:1-1:1),
+LowerIdent(6:1-6:4),OpAssign(6:5-6:6),Newline(1:1-1:1),
+Newline(1:1-1:1),
 StringStart(8:5-8:6),StringPart(8:6-8:9),StringEnd(8:9-8:10),EndOfFile(8:10-8:10),
 ~~~PARSE
-(file (1:1-8:10)
-    (module (1:1-4:7)
-        (exposed_item (3:2-3:5) (lower_ident "foo")))
+(file
+    (module (1:1-4:7) (exposed_item (lower_ident "foo")))
     (decl (6:1-8:10)
         (ident (6:1-6:4) "foo")
         (string (8:5-8:10) (string_part (8:6-8:9) "one"))))
 ~~~FORMATTED
-module [foo]
+module [
+    # some crazy formatting
+    foo,
+]
 
-foo = "one"
+foo = 
+
+    "one"
 ~~~END

src/snapshots/add_var_with_spaces.txt

@@ -8,11 +8,11 @@ add2 = x +      2
 NIL
 ~~~TOKENS
 KwModule(1:1-1:7),OpenSquare(1:8-1:9),LowerIdent(1:9-1:13),CloseSquare(1:13-1:14),Newline(1:1-1:1),
+Newline(1:1-1:1),
 LowerIdent(3:1-3:5),OpAssign(3:6-3:7),LowerIdent(3:8-3:9),OpPlus(3:10-3:11),Int(3:17-3:18),EndOfFile(3:18-3:18),
 ~~~PARSE
-(file (1:1-3:18)
-    (module (1:1-1:14)
-        (exposed_item (1:9-1:13) (lower_ident "add2")))
+(file
+    (module (1:1-1:14) (exposed_item (lower_ident "add2")))
     (decl (3:1-3:18)
         (ident (3:1-3:5) "add2")
         (binop

src/snapshots/expr_if_missing_else.txt

@@ -8,9 +8,10 @@ foo = if tru then 0
 PARSER: no_else
 ~~~TOKENS
 KwModule(1:1-1:7),OpenSquare(1:8-1:9),CloseSquare(1:9-1:10),Newline(1:1-1:1),
+Newline(1:1-1:1),
 LowerIdent(3:1-3:4),OpAssign(3:5-3:6),KwIf(3:7-3:9),LowerIdent(3:10-3:13),LowerIdent(3:14-3:18),Int(3:19-3:20),EndOfFile(3:20-3:20),
 ~~~PARSE
-(file (1:1-3:20)
+(file
     (module (1:1-1:10))
     (decl (3:1-3:20)
         (ident (3:1-3:4) "foo")

src/snapshots/expr_no_space_dot_int.txt

@@ -8,9 +8,10 @@ foo = asd.0
 PARSER: expr_no_space_dot_int
 ~~~TOKENS
 KwModule(1:1-1:7),OpenSquare(1:8-1:9),CloseSquare(1:9-1:10),Newline(1:1-1:1),
+Newline(1:1-1:1),
 LowerIdent(3:1-3:4),OpAssign(3:5-3:6),LowerIdent(3:7-3:10),NoSpaceDotInt(3:10-3:12),EndOfFile(3:12-3:12),
 ~~~PARSE
-(file (1:1-3:12)
+(file
     (module (1:1-1:10))
     (decl (3:1-3:12)
         (ident (3:1-3:4) "foo")

src/snapshots/fuzz_crash/fuzz_crash_001.txt

@@ -10,7 +10,7 @@ PARSER: unexpected_token
 ~~~TOKENS
 LowerIdent(1:1-1:3),OpBar(1:3-1:4),OpPercent(1:4-1:5),EndOfFile(1:5-1:5),
 ~~~PARSE
-(file (1:1-1:5)
+(file
     (malformed_header (1:1-1:3) "missing_header")
     (malformed_expr (1:3-1:5) "unexpected_token"))
 ~~~FORMATTED

src/snapshots/fuzz_crash/fuzz_crash_002.txt

@@ -26,7 +26,7 @@ PARSER: unexpected_token
 ~~~TOKENS
 LowerIdent(1:1-1:5),OpColon(1:5-1:6),MalformedUnknownToken(1:6-1:7),OpColon(1:7-1:8),OpColon(1:8-1:9),OpColon(1:9-1:10),OpColon(1:10-1:11),OpColon(1:11-1:12),OpColon(1:12-1:13),OpColon(1:13-1:14),OpColon(1:14-1:15),OpColon(1:15-1:16),OpColon(1:16-1:17),OpColon(1:17-1:18),OpColon(1:18-1:19),OpColon(1:19-1:20),OpColon(1:20-1:21),LowerIdent(1:21-1:23),OpenSquare(1:23-1:24),OpPercent(1:24-1:25),EndOfFile(1:25-1:25),
 ~~~PARSE
-(file (1:1-1:25)
+(file
     (malformed_header (1:1-1:5) "missing_header")
     (malformed_expr (1:5-1:6) "unexpected_token")
     (malformed_expr (1:6-1:7) "unexpected_token")
@@ -47,23 +47,5 @@ LowerIdent(1:1-1:5),OpColon(1:5-1:6),MalformedUnknownToken(1:6-1:7),OpColon(1:7-
     (ident (1:21-1:23) "" "le")
     (malformed_expr (1:23-1:25) "unexpected_token"))
 ~~~FORMATTED
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
 le
-
-
 ~~~END

src/snapshots/fuzz_crash/fuzz_crash_003.txt

@@ -11,7 +11,7 @@ PARSER: missing_header
 ~~~TOKENS
 OpAssign(1:2-1:3),StringStart(1:4-1:5),StringPart(1:5-1:7),EndOfFile(1:7-1:7),
 ~~~PARSE
-(file (1:2-1:7)
+(file
     (malformed_header (1:2-1:3) "missing_header")
     (string (1:4-1:7) (string_part (1:5-1:7) "te")))
 ~~~FORMATTED

src/snapshots/fuzz_crash/fuzz_crash_004.txt

@@ -8,7 +8,7 @@ PARSER: missing_header
 ~~~TOKENS
 UpperIdent(1:1-1:2),EndOfFile(1:2-1:2),
 ~~~PARSE
-(file (1:1-1:2) (malformed_header (1:1-1:2) "missing_header"))
+(file (malformed_header (1:1-1:2) "missing_header"))
 ~~~FORMATTED
 
 ~~~END

src/snapshots/fuzz_crash/fuzz_crash_005.txt

@@ -8,7 +8,7 @@ PARSER: missing_header
 ~~~TOKENS
 LowerIdent(1:1-1:5),EndOfFile(1:5-1:5),
 ~~~PARSE
-(file (1:1-1:5) (malformed_header (1:1-1:5) "missing_header"))
+(file (malformed_header (1:1-1:5) "missing_header"))
 ~~~FORMATTED
 
 ~~~END

src/snapshots/fuzz_crash/fuzz_crash_007.txt

@@ -10,11 +10,10 @@ PARSER: unexpected_token
 ~~~TOKENS
 LowerIdent(1:1-1:4),NoSpaceDotInt(1:4-1:6),NoSpaceDotLowerIdent(1:6-1:8),EndOfFile(1:8-1:8),
 ~~~PARSE
-(file (1:1-1:8)
+(file
     (malformed_header (1:1-1:4) "missing_header")
     (malformed_expr (1:4-1:6) "unexpected_token")
     (malformed_expr (1:6-1:8) "unexpected_token"))
 ~~~FORMATTED
 
-
 ~~~END

src/snapshots/fuzz_crash/fuzz_crash_008.txt

@@ -12,7 +12,7 @@ PARSER: unexpected_token
 ~~~TOKENS
 OpBar(1:1-1:2),OpBar(1:3-1:4),Int(1:4-1:5),EndOfFile(1:5-1:5),
 ~~~PARSE
-(file (1:1-1:5)
+(file
     (malformed_header (1:1-1:2) "missing_header")
     (malformed_expr (1:3-1:5) "unexpected_token"))
 ~~~FORMATTED

src/snapshots/fuzz_crash/fuzz_crash_009.txt

@@ -17,19 +17,25 @@ TOKENIZE: (6:6-6:12) UnclosedString:
      ^^^^^^
 PARSER: missing_header
 ~~~TOKENS
-LowerIdent(1:2-1:3),OpenCurly(1:3-1:4),LowerIdent(1:4-1:5),Comma(1:5-1:6),Newline(1:6-1:6),
+LowerIdent(1:2-1:3),OpenCurly(1:3-1:4),LowerIdent(1:4-1:5),Comma(1:5-1:6),Newline(1:1-1:1),
 CloseCurly(2:6-2:7),Newline(1:1-1:1),
-LowerIdent(4:1-4:4),OpAssign(4:5-4:6),Newline(1:5-1:5),
+Newline(1:1-1:1),
+LowerIdent(4:1-4:4),OpAssign(4:5-4:6),Newline(1:1-1:1),
+Newline(1:1-1:1),
 StringStart(6:5-6:6),StringPart(6:6-6:12),EndOfFile(6:12-6:12),
 ~~~PARSE
-(file (1:2-6:12)
+(file
     (malformed_header (1:2-1:3) "missing_header")
-    (record (1:3-4:4) (field "o"))
+    (record (1:3-2:7) (field "o"))
     (decl (4:1-6:12)
         (ident (4:1-4:4) "foo")
         (string (6:5-6:12) (string_part (6:6-6:12) "onmo %"))))
 ~~~FORMATTED
-{ o }
+{
+    o,
+}
 
-foo = "onmo %"
+foo = 
+
+    "onmo %"
 ~~~END

src/snapshots/fuzz_crash/fuzz_crash_010.txt

@@ -19,19 +19,23 @@ TOKENIZE: (5:6-5:35) UnclosedString:
      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 PARSER: missing_header
 ~~~TOKENS
-UpperIdent(1:1-1:2),OpenCurly(1:2-1:3),LowerIdent(1:3-1:4),Comma(1:4-1:5),Newline(1:5-1:5),
+UpperIdent(1:1-1:2),OpenCurly(1:2-1:3),LowerIdent(1:3-1:4),Comma(1:4-1:5),Newline(1:1-1:1),
 CloseCurly(2:6-2:7),Newline(1:1-1:1),
-LowerIdent(3:1-3:4),OpAssign(3:5-3:6),Newline(1:5-1:5),
+LowerIdent(3:1-3:4),OpAssign(3:5-3:6),Newline(1:1-1:1),
+Newline(1:1-1:1),
 StringStart(5:5-5:6),StringPart(5:6-5:35),EndOfFile(5:35-5:35),
 ~~~PARSE
-(file (1:1-5:35)
+(file
     (malformed_header (1:1-1:2) "missing_header")
-    (record (1:2-3:4) (field "o"))
+    (record (1:2-2:7) (field "o"))
     (decl (3:1-5:35)
         (ident (3:1-3:4) "foo")
         (string (5:5-5:35) (string_part (5:6-5:35) "on        (string 'onmo %')))"))))
 ~~~FORMATTED
-{ o }
+{
+    o,
+}
+foo = 
 
-foo = "on        (string 'onmo %')))"
+    "on        (string 'onmo %')))"
 ~~~END

src/snapshots/fuzz_crash/fuzz_crash_011.txt

@@ -11,7 +11,7 @@ PARSER: header_expected_open_square
 ~~~TOKENS
 KwModule(1:1-1:7),UpperIdent(1:8-1:9),UpperIdent(1:10-1:11),EndOfFile(1:11-1:11),
 ~~~PARSE
-(file (1:1-1:11)
+(file
     (malformed_header (1:8-1:9) "header_expected_open_square")
     (tag (1:10-1:11) "F"))
 ~~~FORMATTED

src/snapshots/fuzz_crash/fuzz_crash_012.txt

@@ -11,7 +11,7 @@ PARSER: unexpected_token
 ~~~TOKENS
 OpBar(1:2-1:3),OpBar(1:3-1:4),NoSpaceOpenRound(1:4-1:5),OpBar(1:5-1:6),NoSpaceOpenRound(1:6-1:7),LowerIdent(1:7-1:17),OpBar(1:17-1:18),EndOfFile(1:18-1:18),
 ~~~PARSE
-(file (1:2-1:18)
+(file
     (malformed_header (1:2-1:3) "missing_header")
     (malformed_expr (1:3-1:18) "unexpected_token"))
 ~~~FORMATTED

src/snapshots/fuzz_crash/fuzz_crash_013.txt

@@ -7,9 +7,7 @@ PARSER: missing_header
 ~~~TOKENS
 Int(1:1-1:2),OpenCurly(1:2-1:3),EndOfFile(1:3-1:3),
 ~~~PARSE
-(file (1:1-1:3)
-    (malformed_header (1:1-1:2) "missing_header")
-    (block (1:2-1:3)))
+(file (malformed_header (1:1-1:2) "missing_header") (block))
 ~~~FORMATTED
 {}
 ~~~END

src/snapshots/fuzz_crash/fuzz_crash_014.txt

@@ -14,7 +14,7 @@ MalformedNumberNoDigits(1:1-1:3),NoSpaceDotInt(1:3-1:5),Newline(1:1-1:1),
 MalformedNumberNoDigits(2:1-2:6),Newline(1:1-1:1),
 MalformedNumberBadSuffix(3:1-3:5),EndOfFile(3:5-3:5),
 ~~~PARSE
-(file (1:1-3:5)
+(file
     (malformed_header (1:1-1:3) "missing_header")
     (malformed_expr (1:3-1:5) "unexpected_token")
     (malformed_expr (2:1-2:6) "unexpected_token")

src/snapshots/fuzz_crash/fuzz_crash_015.txt

@@ -18,7 +18,7 @@ Int(2:1-2:4),Newline(1:1-1:1),
 Int(3:1-3:4),NoSpaceDotInt(3:4-3:6),Newline(1:1-1:1),
 Int(4:1-4:3),EndOfFile(4:3-4:3),
 ~~~PARSE
-(file (1:1-4:3)
+(file
     (malformed_header (1:1-1:4) "missing_header")
     (malformed_expr (1:4-1:6) "unexpected_token")
     (int (2:1-2:4) "0_0")
@@ -28,6 +28,5 @@ Int(4:1-4:3),EndOfFile(4:3-4:3),
 
 0_0
 
-
 0_
 ~~~END

src/snapshots/fuzz_crash/fuzz_crash_016.txt

@@ -8,7 +8,7 @@ PARSER: unexpected_token
 ~~~TOKENS
 Int(1:1-1:2),OpBar(1:2-1:3),EndOfFile(1:3-1:3),
 ~~~PARSE
-(file (1:1-1:3)
+(file
     (malformed_header (1:1-1:2) "missing_header")
     (malformed_expr (1:2-1:3) "unexpected_token"))
 ~~~FORMATTED

src/snapshots/fuzz_crash/fuzz_crash_017.txt

@@ -11,16 +11,14 @@ PARSER: string_expected_close_interpolation
 LowerIdent(1:1-1:3),OpAssign(1:4-1:5),StringStart(1:6-1:7),StringPart(1:7-1:10),StringEnd(1:10-1:11),Newline(1:1-1:1),
 LowerIdent(2:1-2:4),OpAssign(2:5-2:6),StringStart(2:7-2:8),StringPart(2:8-2:14),OpenStringInterpolation(2:14-2:16),LowerIdent(2:16-2:20),EndOfFile(2:20-2:20),
 ~~~PARSE
-(file (1:1-2:20)
+(file
     (malformed_header (1:1-1:3) "missing_header")
     (malformed_expr (1:4-1:5) "unexpected_token")
     (string (1:6-1:11) (string_part (1:7-1:10) "luc"))
     (decl (2:1-2:20)
         (ident (2:1-2:4) "foo")
-        (malformed_expr (2:20-2:20) "string_expected_close_interpolation")))
+        (malformed_expr (2:7-2:20) "string_expected_close_interpolation")))
 ~~~FORMATTED
-
 "luc"
-
 foo = 
 ~~~END

src/snapshots/fuzz_crash/fuzz_hang_001.txt

@@ -0,0 +1,17 @@
+~~~META
+description=fuzz crash
+verbose-tokens
+~~~SOURCE
+0 (
+~~~PROBLEMS
+PARSER: missing_header
+PARSER: unexpected_token
+~~~TOKENS
+Int(1:1-1:2),OpenRound(1:3-1:4),EndOfFile(1:4-1:4),
+~~~PARSE
+(file
+    (malformed_header (1:1-1:2) "missing_header")
+    (malformed_expr (1:3-1:4) "unexpected_token"))
+~~~FORMATTED
+
+~~~END

src/snapshots/header_expected_open_bracket.txt

@@ -7,7 +7,7 @@ PARSER: header_expected_open_square
 ~~~TOKENS
 KwModule(1:1-1:7),EndOfFile(1:7-1:7),
 ~~~PARSE
-(file (1:1-1:7) (malformed_header (1:7-1:7) "header_expected_open_square"))
+(file (malformed_header (1:7-1:7) "header_expected_open_square"))
 ~~~FORMATTED
 
 ~~~END

src/snapshots/hello_world.txt

@@ -10,12 +10,14 @@ main! = |_| Stdout.line!("Hello, world!")
 NIL
 ~~~TOKENS
 KwApp(1:1-1:4),OpenSquare(1:5-1:6),LowerIdent(1:6-1:11),CloseSquare(1:11-1:12),OpenCurly(1:13-1:14),LowerIdent(1:15-1:17),OpColon(1:17-1:18),KwPlatform(1:19-1:27),StringStart(1:28-1:29),StringPart(1:29-1:54),StringEnd(1:54-1:55),CloseCurly(1:56-1:57),Newline(1:1-1:1),
+Newline(1:1-1:1),
 KwImport(3:1-3:7),LowerIdent(3:8-3:10),NoSpaceDotUpperIdent(3:10-3:17),Newline(1:1-1:1),
+Newline(1:1-1:1),
 LowerIdent(5:1-5:6),OpAssign(5:7-5:8),OpBar(5:9-5:10),Underscore(5:10-5:11),OpBar(5:11-5:12),UpperIdent(5:13-5:19),NoSpaceDotLowerIdent(5:19-5:25),NoSpaceOpenRound(5:25-5:26),StringStart(5:26-5:27),StringPart(5:27-5:40),StringEnd(5:40-5:41),CloseRound(5:41-5:42),EndOfFile(5:42-5:42),
 ~~~PARSE
-(file (1:1-5:42)
-    (app (1:1-1:4) "TODO implement toSExpr for app module header")
-    (import (3:1-5:6) ".Stdout" (qualifier "pf"))
+(file
+    (app (1:1-1:1) "TODO implement toSExpr for app module header")
+    (import (3:1-3:17) ".Stdout" (qualifier "pf"))
     (decl (5:1-5:42)
         (ident (5:1-5:6) "main!")
         (lambda (5:9-5:42)

src/snapshots/if_then_else.txt

@@ -12,22 +12,27 @@ foo = if true A
 NIL
 ~~~TOKENS
 KwModule(1:1-1:7),OpenSquare(1:8-1:9),LowerIdent(1:9-1:12),CloseSquare(1:12-1:13),Newline(1:1-1:1),
-LowerIdent(3:1-3:4),OpAssign(3:5-3:6),KwIf(3:7-3:9),LowerIdent(3:10-3:14),UpperIdent(3:15-3:16),Newline(1:5-1:5),
-KwElse(5:5-5:9),OpenCurly(5:10-5:11),Newline(1:5-1:5),
-UpperIdent(6:5-6:6),Newline(1:5-1:5),
+Newline(1:1-1:1),
+LowerIdent(3:1-3:4),OpAssign(3:5-3:6),KwIf(3:7-3:9),LowerIdent(3:10-3:14),UpperIdent(3:15-3:16),Newline(1:1-1:1),
+Newline(1:1-1:1),
+KwElse(5:5-5:9),OpenCurly(5:10-5:11),Newline(1:1-1:1),
+UpperIdent(6:5-6:6),Newline(1:1-1:1),
 CloseCurly(7:5-7:6),EndOfFile(7:6-7:6),
 ~~~PARSE
-(file (1:1-7:6)
-    (module (1:1-1:13)
-        (exposed_item (1:9-1:12) (lower_ident "foo")))
+(file
+    (module (1:1-1:13) (exposed_item (lower_ident "foo")))
     (decl (3:1-7:6)
         (ident (3:1-3:4) "foo")
         (if_then_else (3:7-7:6)
             (ident (3:10-3:14) "" "true")
             (tag (3:15-3:16) "A")
-            (block (5:10-7:6) (tag (6:5-6:6) "B")))))
+            (block (tag (6:5-6:6) "B")))))
 ~~~FORMATTED
 module [foo]
 
-foo = if true A else B
+foo = if true A
+
+    else {
+        B
+    }
 ~~~END

src/snapshots/primitive/expr_float.txt

@@ -10,14 +10,11 @@ NIL
 KwModule(1:1-1:7),OpenSquare(1:8-1:9),LowerIdent(1:9-1:12),CloseSquare(1:12-1:13),Newline(1:1-1:1),
 LowerIdent(2:1-2:4),OpAssign(2:5-2:6),Float(2:7-2:12),EndOfFile(2:12-2:12),
 ~~~PARSE
-(file (1:1-2:12)
-    (module (1:1-1:13)
-        (exposed_item (1:9-1:12) (lower_ident "foo")))
+(file
+    (module (1:1-1:13) (exposed_item (lower_ident "foo")))
     (decl (2:1-2:12)
         (ident (2:1-2:4) "foo")
         (float (2:7-2:12) "12.34")))
 ~~~FORMATTED
-module [foo]
-
-foo = 12.34
+NO CHANGE
 ~~~END

src/snapshots/primitive/expr_int.txt

@@ -10,14 +10,11 @@ NIL
 KwModule(1:1-1:7),OpenSquare(1:8-1:9),LowerIdent(1:9-1:12),CloseSquare(1:12-1:13),Newline(1:1-1:1),
 LowerIdent(2:1-2:4),OpAssign(2:5-2:6),Int(2:7-2:9),EndOfFile(2:9-2:9),
 ~~~PARSE
-(file (1:1-2:9)
-    (module (1:1-1:13)
-        (exposed_item (1:9-1:12) (lower_ident "foo")))
+(file
+    (module (1:1-1:13) (exposed_item (lower_ident "foo")))
     (decl (2:1-2:9)
         (ident (2:1-2:4) "foo")
         (int (2:7-2:9) "42")))
 ~~~FORMATTED
-module [foo]
-
-foo = 42
+NO CHANGE
 ~~~END

src/snapshots/primitive/expr_string.txt

@@ -12,9 +12,8 @@ KwModule(1:1-1:7),OpenSquare(1:8-1:9),LowerIdent(1:9-1:12),CloseSquare(1:12-1:13
 LowerIdent(2:1-2:5),OpAssign(2:6-2:7),StringStart(2:8-2:9),StringPart(2:9-2:12),StringEnd(2:12-2:13),Newline(1:1-1:1),
 LowerIdent(3:1-3:4),OpAssign(3:5-3:6),StringStart(3:7-3:8),StringPart(3:8-3:14),OpenStringInterpolation(3:14-3:16),LowerIdent(3:16-3:20),CloseStringInterpolation(3:20-3:21),StringPart(3:21-3:21),StringEnd(3:21-3:22),EndOfFile(3:22-3:22),
 ~~~PARSE
-(file (1:1-3:22)
-    (module (1:1-1:13)
-        (exposed_item (1:9-1:12) (lower_ident "foo")))
+(file
+    (module (1:1-1:13) (exposed_item (lower_ident "foo")))
     (decl (2:1-2:13)
         (ident (2:1-2:5) "name")
         (string (2:8-2:13) (string_part (2:9-2:12) "luc")))
@@ -25,9 +24,5 @@ LowerIdent(3:1-3:4),OpAssign(3:5-3:6),StringStart(3:7-3:8),StringPart(3:8-3:14),
             (ident (3:16-3:20) "" "name")
             (string_part (3:21-3:21) ""))))
 ~~~FORMATTED
-module [foo]
-
-name = "luc"
-
-foo = "hello ${name}"
+NO CHANGE
 ~~~END

src/snapshots/primitive/expr_tag.txt

@@ -10,14 +10,11 @@ NIL
 KwModule(1:1-1:7),OpenSquare(1:8-1:9),LowerIdent(1:9-1:12),CloseSquare(1:12-1:13),Newline(1:1-1:1),
 LowerIdent(2:1-2:4),OpAssign(2:5-2:6),UpperIdent(2:7-2:15),EndOfFile(2:15-2:15),
 ~~~PARSE
-(file (1:1-2:15)
-    (module (1:1-1:13)
-        (exposed_item (1:9-1:12) (lower_ident "foo")))
+(file
+    (module (1:1-1:13) (exposed_item (lower_ident "foo")))
     (decl (2:1-2:15)
         (ident (2:1-2:4) "foo")
         (tag (2:7-2:15) "FortyTwo")))
 ~~~FORMATTED
-module [foo]
-
-foo = FortyTwo
+NO CHANGE
 ~~~END