Silicon for VS Code

Syntax highlighting, the Sigil Dark color theme, and a built-in language server for the Silicon programming language — a bootstrappable language that targets WebAssembly Text Format (WAT) and runs under WASI.

The language server (LSP) is bundled directly in the VSIX. No separate clone, no extra bun install — node is enough.

What's in here

• Silicon language grammar (syntaxes/silicon.tmLanguage.json) — TextMate scopes for .si files: definition keywords (@let, @fn, @var, @type, @extern, @stratum_*), control flow (@if, @loop, @match, @return, @break, @continue), function calls (&name, &mod::fn), primitive types (Int, Float, Bool, String, Void), string literals with \n / \t / \\ escapes, numeric literals (decimal, hex, binary, octal, float), and # line comments / ## doc comments.
• Sigil Dark color theme (themes/sigil-dark-color-theme.json) — the same palette the Sigil playground uses, ported to VS Code's full UI surface (editor, sidebar, tabs, status bar, terminal).
• Language configuration (language-configuration.json) — bracket pairs, auto-closing single quotes, line-comment toggle.
• Language server (lsp/) — diagnostics, document symbols (outline / breadcrumb), go-to-definition, and hover for any .si file in the workspace. The extension spawns this server as a node child process on .si activation; the bundled lsp/dist/index.js is included in the VSIX.
• VS Code client (client/) — thin wrapper that wires the language server into the editor.

Language server settings

Command: Silicon: Restart LSP in the command palette (Ctrl/Cmd-Shift-P) restarts the server without reloading the window.

Install (Marketplace)

Coming soon — for now, install locally per the section below.

Install (local development)

git clone https://github.com/natescode/silicon-vscode.git
cd silicon-vscode
bun install
bun run build              # builds client + server bundles
# Run the extension in a fresh VS Code window:
code --extensionDevelopmentPath="$(pwd)"

Or symlink into ~/.vscode/extensions/:

ln -s "$(pwd)" ~/.vscode/extensions/silicon-vscode

Then in VS Code:

1. Open any .si file — syntax highlighting kicks in automatically.
2. Cmd/Ctrl + K, Cmd/Ctrl + T → pick Sigil Dark.

Build + test

bun run build               # bundles client/dist/extension.js + lsp/dist/index.js
bun run test:server         # LSP smoke test (dev mode, runs under bun)
bun run scripts/smoke-bundled.ts   # LSP smoke test against the bundled artifact under node

Repository layout

client/                 VS Code extension client
  src/extension.ts      Spawns lsp/dist/index.js on .si activation
  dist/extension.js     Bundled output (.vsix)
lsp/                    Language Server Protocol implementation
  src/
    index.ts            stdio entry + handler registry
    workspace.ts        per-doc parse/elaborate/typecheck cache
    handlers/           diagnostics, document-symbol, definition, hover
    smoke.test.ts       bun:test wrapper around _smoke-run.ts
  dist/                 Bundled output (.vsix)
    index.js
    std.wat             runtime asset (read by the bundled compiler)
    silicon-official.ohm
src/                    Vendored snapshot of the Sigil compiler frontend
                        (parser, AST, elaborator, typechecker, IR,
                        codegen, modules, platforms).  Frozen at
                        natescode/sigil commit b08f6c4c — the last
                        point before sigil went 100% self-hosted.
                        Imported by lsp/src/* via `../../src/...`
                        relative paths.
boot/strata/builtin/    Silicon strata source loaded at request time
                        by the bundled server.
syntaxes/, themes/      TextMate grammar + color theme
scripts/                Dev scripts (bundled-artifact smoke runner)

Why the LSP is bundled here

The language server source used to live in its own repo (natescode/silicon-lsp) on the theory that vim / emacs / helix users might want to use it standalone. In practice, every real user was going through VS Code, and the separate repo just added ceremony to releases without buying anything. Bundled distribution gives end users a single Marketplace install, no bun requirement, no extra clones.

If you actually want to drive the LSP from another editor: the bundled lsp/dist/index.js is a standalone node-runnable LSP binary. Point your editor's LSP client at node /path/to/lsp/dist/index.js --stdio.

Palette

The theme reuses the exact CSS variables from the playground's sigil-dark:

License

MIT, matching the upstream Sigil project.