How do I get a railroad diagram (syntax diagram) in Docbook starting from an EBNF source file?

Docbook 5 apparently supports EBNF. But it doesn't output a railroad diagram. I开发者_C百科s it possible to make it output a railroad diagram (AKA syntax diagram)?

The DocBook schema includes XML elements for representing EBNF production rules, and HTML/FO output can be generated using the DocBook XSL stylesheets. However, there is no direct support for producing railroad diagrams. There are tools for creating railroad diagrams from plaintext EBNF sources, but I am not aware of any programs that do the same based on DocBook EBNF markup.