I just released a new version of Grako:

https://pypi.python.org/pypi/grako/1.3.0

The most relevant change is the the memoization cache optimization thanks to the advice given by  Kota Mizushima.

This time I'm requesting help on the work on the  semantic_delegate branch of the repository, because that's the way to go for amazing performance with parsers and translators in Python.