CoHDL — VS Code extension

Syntax highlighting and language-server support for CoHDL (.cohdl) source, packaging the built-in cohdl lsp (RFC-014) as an installable extension (RFC-019 / DR-025).

It adds no new diagnostics or compiler behavior — it is a TextMate grammar (for color) plus a thin vscode-languageclient wiring that spawns cohdl lsp, turning on RFC-014's four capabilities: diagnostics, hover, goto-definition, and find-references. The server's output is exactly cohdl lsp's, unmodified.

Build from source

Requires Node.js ≥ 18 and a built cohdl binary (cargo build in the repo root).

cd editors/vscode
npm install
npm run compile      # tsc -> out/extension.js
npm test             # grammar-coverage regression test
npm run package      # -> cohdl.vsix

Install locally

code --install-extension cohdl.vsix

Configure

The extension resolves the cohdl binary via the cohdl.path setting (default "cohdl", found on PATH). Point it at a workspace build if needed:

{
  "cohdl.path": "${workspaceFolder}/target/debug/cohdl"
}

If the binary cannot be started, the extension shows a visible error notification (never a silently blank Problems panel).

Editor support beyond VS Code

Neovim, Emacs, and other generic LSP clients don't need this package — a launch config is enough; see docs/lsp.md for those snippets. This extension exists because VS Code needs a packaged TextMate grammar to get syntax color at all, which the LSP protocol has no verb for.

Maintenance note (grammar drift)

syntaxes/cohdl.tmLanguage.json is hand-authored from the Accepted grammar (RFC-001…018). Any future RFC that adds, renames, or removes a top-level keyword must update this grammar in the same change — the same "ship with its spec update" discipline the language spec itself follows. npm test catches a keyword that falls through to unstyled text, but cannot catch one styled as the wrong class; grammar review remains a human step.

CoHDL