Andrew Dalke released python4ply 1.0 today. It might be useful as part of the RuleCompiler since I wouldn't have to constrain the rule syntax to Python's.
One of the main reasons for doing the rule compiler the way I am, is so I wouldn't have to re-implement a parser for Python's syntax but now that Andrew's gone and done just that... I don't know. This is from his announcement:
You might use python4ply to experiment with variations in the Python language. The PLY-based lexer and parser are much easier to change than the C implementation Python itself uses or even the ones written in Python which are part of the standard library.It would be cool to have support for other syntaxes as well... I'll have to think about it.