feat: Fickl performance experiments

.claude/settings.json

@@ -1,8 +1,8 @@
 {
   "permissions": {
     "allow": [
-      "Bash(./build.sh fable-library *)",
-      "Bash(./build.sh test *)"
+      "Bash(dotnet run --project src/Fickl.Build -- fable-library *)",
+      "Bash(dotnet run --project src/Fickl.Build -- test *)"
     ],
     "deny": [
       "Read(lib/fcs/**)",

.github/actions/setup-node/action.yml

@@ -8,7 +8,7 @@ runs:
       with:
         node-version-file: package.json
         cache: npm
-        # build.sh also installs in src/fable-compiler-js, src/fable-standalone and tests/React.
+        # The build also installs in src/fable-compiler-js, src/fable-standalone and tests/React.
         cache-dependency-path: |
           **/package-lock.json
           !**/node_modules/**

.github/workflows/build.yml

@@ -87,11 +87,11 @@ jobs:
 
       - name: Fable Tests - JavaScript (linux)
         if: matrix.platform == 'ubuntu-latest'
-        run: ./build.sh test javascript
+        run: dotnet run --project src/Fickl.Build -- test javascript
 
       - name: Fable Tests - JavaScript (Windows)
         if: matrix.platform == 'windows-latest'
-        run: .\build.bat test javascript
+        run: dotnet run --project src/Fickl.Build -- test javascript
 
   # Separate build job for TypeScript
   build-typescript:
@@ -108,7 +108,7 @@ jobs:
         uses: ./.github/actions/setup-node
 
       - name: Fable Tests - TypeScript
-        run: ./build.sh test typescript
+        run: dotnet run --project src/Fickl.Build -- test typescript
 
     # - name: Fable Tests - TypeScript
     #   run: dotnet fsi build.fsx test-ts
@@ -128,7 +128,7 @@ jobs:
         uses: ./.github/actions/setup-node
 
       - name: Fable Tests
-        run: ./build.sh test integration
+        run: dotnet run --project src/Fickl.Build -- test integration
 
   # Separate build job for Standalone
   build-standalone:
@@ -145,7 +145,7 @@ jobs:
         uses: ./.github/actions/setup-node
 
       - name: Fable Tests
-        run: ./build.sh test standalone
+        run: dotnet run --project src/Fickl.Build -- test standalone
 
   # Separate build job for Python since we use a test matrix (will run in parallell)
   build-python:
@@ -179,7 +179,7 @@ jobs:
 
       - name: Fable Library - Python (linux)
         if: matrix.platform == 'ubuntu-latest'
-        run: ./build.sh fable-library --python
+        run: dotnet run --project src/Fickl.Build -- fable-library python
 
       # PEP 561 requires the marker inside the package directory. CopyStage filters
       # by extension, so it is easy to drop again; without it mypy refuses to read
@@ -192,15 +192,15 @@ jobs:
 
       - name: Fable Library - Python (Windows)
         if: matrix.platform == 'windows-latest'
-        run: .\build.bat fable-library --python
+        run: dotnet run --project src/Fickl.Build -- fable-library python
 
       - name: Fable Tests - Python (linux)
         if: matrix.platform == 'ubuntu-latest'
-        run: ./build.sh test python
+        run: dotnet run --project src/Fickl.Build -- test python
 
       - name: Fable Tests - Python (Windows)
         if: matrix.platform == 'windows-latest'
-        run: .\build.bat test python
+        run: dotnet run --project src/Fickl.Build -- test python
 
   # Native/Rust-extension unit tests for the published fable-library package.
   # These live in src/fable-library-py/tests and exercise hand-written sources
@@ -283,10 +283,10 @@ jobs:
           components: rustfmt
 
       - name: Fable Library - Rust
-        run: ./build.sh fable-library --rust
+        run: dotnet run --project src/Fickl.Build -- fable-library rust
 
       - name: Fable Tests - Rust
-        run: ./build.sh test rust --features "${{ matrix.features }}"
+        run: dotnet run --project src/Fickl.Build -- test rust --features "${{ matrix.features }}"
 
   # Separate build job for Dart
   build-dart:
@@ -307,7 +307,7 @@ jobs:
         uses: dart-lang/setup-dart@v1
 
       - name: Fable Tests - Dart
-        run: ./build.sh test dart
+        run: dotnet run --project src/Fickl.Build -- test dart
 
   # Separate build job for Beam (Erlang)
   build-beam:
@@ -327,7 +327,7 @@ jobs:
           rebar3-version: "3"
 
       - name: Fable Tests - Beam
-        run: ./build.sh test beam
+        run: dotnet run --project src/Fickl.Build -- test beam
 
   # Separate job to run F# analyzers
   analyzers:

.github/workflows/easybuild-shipit.yml

@@ -31,7 +31,7 @@ jobs:
         uses: ./.github/actions/setup-dotnet
       # Run your tests before generating the changelog to make sure everything is working fine before creating a pull request.
       - name: Prepare for release
-        run: ./build.sh prepare-release
+        run: dotnet run --project src/Fable.Build -- prepare-release
       - name: ShipIt (Pull Request)
         # Configure add --pre-release below when we want to create a pre-release, e.g. --pre-release beta
         run: dotnet shipit
@@ -80,7 +80,7 @@ jobs:
 
       - name: Build, and Release
         run: |
-            ./build.sh automated-release
+            dotnet run --project src/Fable.Build -- automated-release
         env:
           FABLE_NUGET_KEY: ${{ steps.login.outputs.NUGET_API_KEY }}
           GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}

.github/workflows/publish-pypi.yml

@@ -36,7 +36,7 @@ jobs:
       - name: Install Maturin
         run: uv tool install maturin
       - name: Transpile F# to Python
-        run: ./build.sh fable-library --python
+        run: dotnet run --project src/Fickl.Build -- fable-library python
       - name: Install Dunamai
         run: uv tool install dunamai
       - name: Set version

.github/workflows/python-type-checking.yml

@@ -42,7 +42,7 @@ jobs:
           pipx install maturin
 
       - name: Build Python (compile only)
-        run: ./build.sh test python --compile-only
+        run: dotnet run --project src/Fickl.Build -- test python --compile-only
 
       - name: Run Pyright and collect errors
         id: pyright

.vscode/tasks.json

@@ -22,91 +22,71 @@
         {
             "label": "Build fable-library - JavaScript",
             "type": "shell",
+            "command": "dotnet",
             "args": [
+                "run",
+                "--project",
+                "src/Fickl.Build",
+                "--",
                 "fable-library",
-                "--javascript"
+                "javascript"
             ],
-            "linux": {
-                "command": "${workspaceFolder}/build.sh"
-            },
-            "osx": {
-                "command": "${workspaceFolder}/build.sh"
-            },
-            "windows": {
-                "command": "${workspaceFolder}/build.cmd"
-            },
             "problemMatcher": []
         },
         {
             "label": "Build fable-library - TypeScript",
             "type": "shell",
+            "command": "dotnet",
             "args": [
+                "run",
+                "--project",
+                "src/Fickl.Build",
+                "--",
                 "fable-library",
-                "--typescript"
+                "typescript"
             ],
-            "linux": {
-                "command": "${workspaceFolder}/build.sh"
-            },
-            "osx": {
-                "command": "${workspaceFolder}/build.sh"
-            },
-            "windows": {
-                "command": "${workspaceFolder}/build.cmd"
-            },
             "problemMatcher": []
         },
         {
             "label": "Build fable-library - Python",
             "type": "shell",
+            "command": "dotnet",
             "args": [
+                "run",
+                "--project",
+                "src/Fickl.Build",
+                "--",
                 "fable-library",
-                "--python"
+                "python"
             ],
-            "linux": {
-                "command": "${workspaceFolder}/build.sh"
-            },
-            "osx": {
-                "command": "${workspaceFolder}/build.sh"
-            },
-            "windows": {
-                "command": "${workspaceFolder}/build.cmd"
-            },
             "problemMatcher": []
         },
         {
             "label": "Build fable-library - Dart",
             "type": "shell",
+            "command": "dotnet",
             "args": [
+                "run",
+                "--project",
+                "src/Fickl.Build",
+                "--",
                 "fable-library",
-                "--dart"
+                "dart"
             ],
-            "linux": {
-                "command": "${workspaceFolder}/build.sh"
-            },
-            "osx": {
-                "command": "${workspaceFolder}/build.sh"
-            },
-            "windows": {
-                "command": "${workspaceFolder}/build.cmd"
-            },
             "problemMatcher": []
         },
         {
             "label": "Build fable-library - Rust",
             "type": "shell",
+            "command": "dotnet",
             "args": [
+                "run",
+                "--project",
+                "src/Fickl.Build",
+                "--",
                 "fable-library",
-                "--rust"
+                "rust"
             ],
-            "linux": {
-                "command": "${workspaceFolder}/build.sh"
-            },
-            "osx": {
-                "command": "${workspaceFolder}/build.sh"
-            },
-            "windows": {
-                "command": "${workspaceFolder}/build.cmd"
-            },
             "problemMatcher": []
         },
         {

AGENTS.md

@@ -8,30 +8,30 @@ Fable is an F# to multi-language compiler that transpiles F# code to JavaScript,
 
 ## Build Commands
 
-The build system is implemented in F# at `src/Fable.Build/`. All commands go through `build.sh` (or `build.bat` on Windows):
+The build system is implemented in F# at `src/Fable.Build/`. All commands go through `src/Fickl.Build/`, which runs the same Fable.Build handlers:
 
 ```bash
-./build.sh                                        # Show all available commands
+dotnet run --project src/Fickl.Build -- --help                                  # Show all available commands
 
 # Build runtime libraries
-./build.sh fable-library --javascript             # Also: --typescript, --python, --dart, --rust, --beam
+dotnet run --project src/Fickl.Build -- fable-library javascript                # Also: typescript, python, dart, rust, beam
 
 # Run tests (targets: javascript, typescript, python, dart, rust, beam, integration)
-./build.sh test javascript
-./build.sh test javascript --watch                # Watch mode (recompile on changes)
-./build.sh test javascript --force-fable-library  # Force fable-library rebuild (needed if you modified Fable compiler to fix the generation of `src/fable-library-*/**/*.fs` files)
+dotnet run --project src/Fickl.Build -- test javascript
+dotnet run --project src/Fickl.Build -- test javascript --watch                 # Watch mode (recompile on changes)
+dotnet run --project src/Fickl.Build -- test javascript --force-fable-library   # Force fable-library rebuild (needed if you modified Fable compiler to fix the generation of `src/fable-library-*/**/*.fs` files)
 
 # Python-specific options
-./build.sh test python --skip-fable-library-core  # Skip slow Rust extension + .pyi rebuild (Python only)
-./build.sh test python --type-check               # Run Pyright type checking on Python output
+dotnet run --project src/Fickl.Build -- test python --skip-fable-library-core   # Skip slow Rust extension + .pyi rebuild (Python only)
+dotnet run --project src/Fickl.Build -- test python --type-check                # Run Pyright type checking on Python output
 
 # Quick iteration (test on a minimal project)
-./build.sh quicktest javascript                   # Also: typescript, python, dart, rust, beam
+dotnet run --project src/Fickl.Build -- quicktest javascript                    # Also: typescript, python, dart, rust, beam
 ```
 
 In most cases, you should not need to use `--force-fable-library`. Only use it if you modified compiler code that affects how F# files used in `src/fable-library-*/` are generated (e.g., changes to `FSharp2Fable.fs` that affect how F# AST is transformed into Fable AST for library files).
 
-When running Python tooling directly with `uv` (e.g. `pytest`, `pyright`, `maturin`, ad-hoc scripts) instead of through `build.sh`, always pass `--frozen` (e.g. `uv run --frozen pytest`). Plain `uv run` silently resolves and rewrites `uv.lock` as a side effect of just running a command. If a command fails because the lock is out of date, stop and ask rather than letting `uv` update it.
+When running Python tooling directly with `uv` (e.g. `pytest`, `pyright`, `maturin`, ad-hoc scripts) instead of through the build, always pass `--frozen` (e.g. `uv run --frozen pytest`). Plain `uv run` silently resolves and rewrites `uv.lock` as a side effect of just running a command. If a command fails because the lock is out of date, stop and ask rather than letting `uv` update it.
 
 Build output goes to `temp/`: transpiled runtime libraries in `temp/fable-library-<target>/` and test output in `temp/tests/<target>/` (e.g., `temp/fable-library-beam/` and `temp/tests/beam/`).
 
@@ -100,7 +100,7 @@ Be careful when modifying shared files like `FableTransforms.fs`, `Transforms.Ut
 
 All code in `fable-library-py` must be fully type-annotated using Python 3.13-compatible syntax, including PEP 695 type parameters. Avoid `Any`, `cast()`, and `# type: ignore` — these require justification. Keep functions small and simple: extract helpers and use early returns. The Rust extension modules (`fable-library-core`) exist to provide correct .NET semantics for numerics, arrays, etc. — not for performance (the FFI crossing is expensive).
 
-All transpiled Python code is type-checked with Pyright at standard settings (`./build.sh test python --type-check`). Do not introduce type-checking regressions without justification.
+All transpiled Python code is type-checked with Pyright at standard settings (`dotnet run --project src/Fickl.Build -- test python --type-check`). Do not introduce type-checking regressions without justification.
 
 ## Development Workflow
 

README.md

@@ -38,7 +38,7 @@ Make sure the following **requirements** are installed in your system:
 
 ### Build
 
-Run `./build.sh` or `./build.cmd` to see the build options.
+Run `dotnet run --project src/Fickl.Build -- --help` to see the build options.
 
 When using VSCode, you can also run the build tasks from the command palette (Ctrl+Shift+P) by typing `Run Task` and selecting the task you want to run.