Preview Rust /// and //! doc comments as formatted documentation in a side panel — like the built-in Markdown preview, but for Rust doc comments.
Features
Full-file preview — code stays as-is, doc comments are rendered as formatted HTML
Syntax highlighting — Rust code in both source and doc examples is highlighted
Scroll sync — bidirectional scroll sync keeps the editor and preview aligned
Intra-doc links — click [Builder::format] to jump to the symbol definition using rust-analyzer
Rustdoc URL support — relative links like struct.Builder.html#method.init are parsed and navigable
Reference links — [label]: url definitions are resolved and rendered as clickable links
Hidden lines — lines starting with # in doc code examples are hidden (rustdoc convention)
Theme integration — colors follow your VSCode theme (dark, light, high contrast)
Usage
Open a Rust file
Click the preview icon in the editor title bar, or run Rust Doc: Open Preview to the Side from the command palette (Ctrl+Shift+P)
The preview opens in a side panel and updates as you edit
Requirements
VSCode 1.85.0 or later
rust-analyzer (recommended, for intra-doc link navigation)
Installation
From VS Code Marketplace
Search for Rust Doc Side Viewer in the Extensions view (Ctrl+Shift+X).
From VSIX
# Build the extension
npm install
npm run compile
npx @vscode/vsce package --allow-missing-repository -o ./vsix_out/
# Install
code --install-extension ./vsix_out/rustdoc-viewer-*.vsix
How It Works
The extension parses /// and //! doc comment blocks from the active Rust file and renders them as HTML in a WebviewPanel. Code between doc blocks is displayed with syntax highlighting and line numbers. The result is a continuous document where documentation and code are interleaved — similar to how cargo doc renders documentation, but live in your editor.
Clicking on intra-doc links (like [Write]: std::io::Write) uses the same mechanism as Ctrl+click — vscode.executeDefinitionProvider via rust-analyzer — to navigate to the symbol's source.
Contributing
Contributions are welcome! Please open an issue or pull request on GitHub.
# Development
npm install
npm run watch # rebuild on changes
# Press F5 in VSCode to launch Extension Development Host
# Type checking
npm run typecheck
