SvelTeX language support

This extension adds language support — syntax highlighting and a full language server — for SvelTeX files. SvelTeX is a preprocessor for Svelte that aims to combine markdown, Svelte, and (some) LaTeX.

Features

• Svelte + Markdown syntax highlighting (incl. fenced code blocks, though only with ~50 languages).
• Syntax highlighting for math expressions in $...$, $$...$$, \(...\), and \[...\] delimiters.
• LaTeX syntax highlighting in "LaTeX tags" (configurable).
• Turn off highlighting in "Escape tags" (configurable).
• <script> languages: JavaScript, TypeScript
• <style> languages: CSS, SCSS, SASS, PostCSS, Stylus

Language server

The extension also starts the SvelTeX language server (@nvl/sveltex-language-server), which brings IntelliSense to .sveltex files:

• Svelte / Markdown / TypeScript diagnostics, hover, completion, go-to-definition, references, rename and more (the real svelte-language-server, proxied for the Svelte parts of the file).
• In math expressions ($…$, $$…$$, …), TeX command completion (triggered on \) and hover. The hover shows the command's signature, the Unicode symbol it stands for (e.g. ∮ (contour integral)) and a short description, scoped to the project's math backend (KaTeX or MathJax).
• In the YAML / TOML / JSON frontmatter block, hover and completion for the frontmatter keys (title, meta, base, link, …) and the standard <meta> names — each documented, with a link to MDN.
• Inside LaTeX tags, full LaTeX assistance when the TexLab language server is installed and on PATH (otherwise this is skipped silently).
• A Markdown heading outline, folding ranges and selection ranges.

The language server starts automatically; if it cannot start, syntax highlighting still works and the failure is logged to the "SvelTeX Language Server" output channel.

Requirements

This extension requires the svelte.svelte-vscode VS Code extension to be installed. This is because the TextMate grammar for SvelTeX depends on Svelte's TextMate grammar.

Extension Settings

This extension contributes the following settings:

• sveltex.latexTags: Tags to use for LaTeX components. In effect, this will just modify this extension's TextMate grammar so that the contents of these tags are highlighted as LaTeX.
• sveltex.escapeTags: Tags to use for non-TeX verbatim components. In effect, this will just modify this extension's TextMate grammar so that the contents of these tags are highlighted the same way as a plaintext fenced code block would in markdown.

⚠ Note: You might need to reload the window for the changes to take effect.

Limitations

• In LaTeX / math expressions, you may sometimes wish to have unbalanced brackets (e.g., [0, 1) for intervals). Because of this, bracket matching inside math scopes is turned off.

Known Issues

• For <style> tags, LESS is not supported.
• For <script> tags, CoffeeScript is not supported. However, since SvelteKit doesn't support CoffeeScript, this is not a priority.