Awesome

A WebExtension compatible with Chrome, Firefox and Edge to display syntax-diagrams for Rust's macro_rules!() on docs.rs, doc.rust-lang.org and all other pages generated by rustdoc.

A pre-built version for Chrome is published here, for Firefox here, for Edge here.

macro_railroad_ext is also integrated into Rust Search Extension

The extension uses macro_railroad to generate diagrams. The diagrams are shown beneath each macro-block. Use the icons in the lower right corner to control options and expand the diagram to fullscreen.

To modify and build the extension locally:

• Install the wasm-pack binary from crates.io.
• The package in wasm_src can be executed via wasm-pack build -t no-modules to build destination wasm package, although the Makefile usually takes care of that.
• make test executes the integration tests; Chrome is required.
• make screenshots takes a couple of screenshots on common pages for visual inspection; Chrome is required.
• make playground builds the extension from source and starts a blank-profile Chrome with the extension loaded; press ctrl+c to quit.
• make packed.zip builds the extension's compressed archive, which can be loaded into a browser as a temporary extension.
• Go to "about:debugging" (Firefox) or "chrome://extensions" (Chrome) and use "Load temporary Add-on"/"Load local extension" with manifest.json/packed.zip to load the extension.

Note: The only reason this extension requests access to file:///* is local documentation; no data is ever transferred. You may need to enable "Allow access to file URLs" in Chromium-based browsers to use the extension with local documentation.