This is a demonstration of a pure-rust library to generate syntax diagrams for macro_rules!().

Diagrams are generated fully automatically from rust-source as Scalable Vector Graphics, using customizable CSS for layout.

Paste a macro_rules!()-block into the text-area on the left; modify them as you wish. A wasm-blob will generate a syntax-diagram as an SVG in the area below.
If you found a bug, a quirk or a macro that doesn't parse but should, please report it liberally.

Here are some examples:

bitflags!() from the `bitflags`-crate cond_reduce!() from `syn` method!() from `nom` cfg_if!() from `cfg-if` panic!() from the standard library

gfx_defines!() from `gfx-rs` sep!() from `nom` named_attrs!() from `nom` verify!() from `nom` HODOR!(), an esolang