A4Doc is a sphinx plugin for documenting Antlr4 grammars.

It’s primary target is to provide some overview for DSL users (generated documentation may not include some nuances essential for compiler developers).

A4Doc's features are:

* a new domain with grammar and rule directives called ``a4``; * directives for rendering railroad diagrams; * directive for extracting documentation comments and rendering docs and diagrams from `.g4` source files.