Tree sitter in Go using a patched modernc.org ccgo

Extremely experimental, but it can parse some stuff already.

mise run test                     # go test ./... (CGO_ENABLED=0)

CI runs tests on every push and pull request across the full native target matrix. Platforms without checked-in grammar/core-*.go bindings codegen on the runner first, then run mise run test.

Grammar C inputs are not git submodules. They are declared in workspaced.cue (#grammar) and placed with workspaced core:place (only src/ / monorepo units). mise installs both go and workspaced:

mise install                      # go + workspaced from mise.toml
mise run grammars:sync            # workspaced codebase apply
./setup-grammars owner/tree-sitter-foo   # add a #grammar entry
mise run grammars:lock            # refresh workspaced.lock.json
mise run test                     # pure Go tests (no transpile)

Grammar trees under third-party/tree-sitter-*/ are vendored (committed); pins stay in workspaced.lock.json. Re-sync after changing #grammar entries (mise run grammars:lock && mise run grammars:sync). CI does not re-fetch grammar sources on every run. Do not vendor full application checkouts (tensorflow, django) — those are optional local corpora only and remain gitignored.

Core tree-sitter is a workspaced source (not placed into the repo):

mise run tree-sitter:path   # print/ensure ~/.cache/workspaced/sources/github/…
# or: TREE_SITTER_PATH=/path/to/tree-sitter  (override for codegen)

Parse fixtures (astdump goldens) — one minimal sample per generated language:

testdata/<language>/<file.ext>
testdata/<language>/<file.ext>.golden.json

Sources are declared in cmd/parse/fixture_sources.go. Goldens are grammar.ParseOutput JSON.

UPDATE_GOLDENS=1 go test ./cmd/parse/ -run TestLanguageFixtures   # rewrite sources + goldens
go test ./cmd/parse/ -run TestLanguageFixtures                       # compare goldens

Each language is its own #grammar: name: { … } in workspaced.cue (optional astdump metadata).

Do not transpile locally. Each codegen:* mise task depends on grammars:sync (workspaced) and is intended for CI runners with the right preprocessor. Multi-platform regen is the GitHub Actions matrix on main (merge opens a PR with regenerated bindings).

Outputs: grammar/core-{GOOS}-{GOARCH}.go, grammar/<lang>/grammar-{GOOS}-{GOARCH}.go.

On Windows, codegen prefers x86_64-w64-mingw32-gcc / aarch64-w64-mingw32-gcc / gcc from MinGW on PATH even if CC=clang, and passes -ignore-unsupported-alignment (and friends) to ccgo. On Darwin, availability macros are defined empty and the same ccgo ignores apply. Linux still drops _Float* typedefs after -E.