Language Support

Language Support

Use this to add a new language to basemind's extraction. Supported languages today include Rust, Python, TypeScript/JSX, JavaScript, Go.

Inputs needed

• A tree-sitter grammar crate (e.g. tree-sitter-elixir) reachable via the tree-sitter-language-pack umbrella crate basemind already depends on, or as a direct dep.
• The grammar's upstream queries/tags.scm from the tree-sitter org repo — it's the canonical starting point for symbol + reference extraction.

Steps

1. Register the language

   • Add the lang ID + file extensions to src/lang.rs's language registry.
   • Add the extensions to the scanner's accepted-extension set in src/scanner.rs (or the central glob if one exists).

2. L1 (outline) queries

   • Adapt the upstream tags.scm to basemind's L1 capture shape: @symbol.function, @symbol.method, @symbol.class, etc. mapped to extract::SymbolKind.
   • Place query string in src/queries/<lang>.rs (or under src/extract/queries/, matching the existing layout).
   • Wire into extract::l1::extract's language dispatch.

3. L2 (calls) queries

   • Add a call query: callees as @call.callee plus optional receiver / type info.
   • Wire into extract::l2::extract's dispatch. Remember to populate start_row / start_col on Call.

4. Fixtures + smoke test

   • Add a synthetic file under tests/fixtures/<lang>/ exercising at least: one function def, one method, one call site, one import.
   • Add assertions in tests/mcp_smoke.rs (or a new tests/<lang>_smoke.rs) covering code mode outline + mode references for the fixture.

5. Harden harness canary

   • Pick a real OSS repo for the language (criteria: stable, ≥ a few hundred files, well-known canary symbols). Add to the repo list in tests/harden.rs with a clone URL + optional --depth.
   • Add a >= N canary assertion (code mode references or mode symbols) — see the harness-canary-authoring skill.

6. README

   • Update the supported-languages list with the new language and file extensions.

Pitfalls

• Tree-sitter queries are language-specific; do not copy capture names blindly between grammars (e.g. function.definition vs function_definition). Test against the fixture.
• Don't forget the file-extension glob — extraction is silently skipped otherwise and the symptom is "tool returns 0 hits for a known symbol."
• Eager L2 must be enabled (default) for code mode references to populate on the new language.