Tau Language for VS Code

Syntax highlighting and editor tooling for .tau templates - the template language used by Steno. Language reference: Tau syntax spec.

Features

• Syntax highlighting - HTML base grammar plus Tau's control tags ({#if} / {#each} / {#let}), interpolations, filters, {@html} / {@include} / {@children}, and <Component> tags.
• Bracket/indent awareness - matching and auto-close for { }, tag-aware indent rules.
• Snippets - #if, #if-else, #each, #each-index, #each-else, #let, @html, @include, @children, #comment.
• Language server
  • Diagnostics: unbalanced {#if} / {#each} blocks, stray {:else} / {:else if}, unclosed/mismatched <Component> tags, use of an identifier Tau's expression evaluator always rejects (constructor, eval, __proto__, ...).
  • Completion: built-in filters after |, control-tag snippets after {.
  • Hover: documentation for built-in filters (date, truncate, upper, lower, url).

The diagnostics are a structural linter, not the canonical Tau parser (that parser is internal to @steno/steno and not published as a public subpath import). It won't catch every render-time error - deep expression-grammar validation and cross-file component/include resolution are out of scope for v1 - but it never requires running your project's Deno toolchain to give you feedback.

Development

npm install
npm run build     # bundle client + server into dist/
npm run watch      # rebuild on change
npm run typecheck
npm test           # runs server/test against server/src

Then, in VS Code, F5 (Run Extension) launches an Extension Development Host with this extension loaded.

Packaging

npx @vscode/vsce package

License

MIT