Vox LSP capabilities matrix (research)

Vox LSP capabilities matrix (research)

Naming: File suffix ssot reflects the original plan slug; this page is not B-canon until registered in contracts/documentation/canonical-map.v1.yaml. Use as the working matrix.

See also: Vox compiler architecture (research), language-lsp-parity-findings-2026.md, web-app-archetype-coverage-2026.md.

Crate role

crates/vox-lsp implements a stdio JSON-RPC language server using the compiler’s lex → parse → typecheck_ast_module path (and optional HIR validation). Shared helpers convert typechecker diagnostics to LSP Diagnostic values (severity, code string, structured data for suggestions/fixes).

Capability matrix

Capability	Status	Implementation notes
Publish diagnostics	Implemented	Driven off compiler pipeline; severity mapped from TypeckSeverity.
Diagnostic code	Implemented	Pass-through of typechecker codes where present.
Related fixes in data	Implemented	JSON payload with suggestions and editable replacement ranges.
Completions	Partial	completions module; parity with CLI/vox check not guaranteed without periodic audits.
Hover	Partial / surface-dependent	See Speech reference and archetype coverage gaps for stubbed areas.
Go to definition	Variable	symbols module; cross-file and codegen symbols need explicit tests.
Code actions	Limited	Fix payloads exist in diagnostics; full code-action lifecycle may be incomplete vs spec.
Formatting	Not advertised	initialize omits documentFormattingProvider; use CLI vox fmt. Future LSP formatting must add capability + handler together — see language-formatter-semantics-findings-2026.md.
Workspace symbols	Unknown / TBD	Confirm in main.rs / capability negotiation.

Design constraints

• Single source of diagnostic truth: Prefer emitting diagnostics once in vox-compiler and rendering in LSP rather than reimplementing checks in the server.
• Parity checks: When adding a vox check diagnostic, add or extend an integration test that exercises the LSP path where feasible.

Integration coverage (2026-05-11)

Automated exercises live in crates/vox-integration-tests/tests/lsp_capabilities_test.rs — asserts advertised capabilities vs absent document formatting, plus semantic tokens, completions, hover, symbols, code lenses, and quick-fix extraction.

Next research steps

1. Generate a machine-readable capability table from initialize response + handler registry (or document manually until automated).
2. Align with Phase 1 SSOT collapse for completion sources (vox-language-rules-phase1-ssot-collapse-2026.md).
3. Close archetype-blocked items calling out LSP stubs in web-app-archetype-coverage-2026.md.