Over the past few months, I have been working on a pygments lexer for Perl 6. The lexer is quite dense, so I understand if it takes some time to review. Please don't hesitate to ask if you have any questions or concerns about my code.
Looking good. I need to manually check the lines with (?P= in them, regexlint flagged them as being unusual. For the example files, two things: could you name them .pm6 so "make test" works, and are the source files under an appropriate license to be included in BSD source? I couldn't find their source in a couple minutes of searching, is it something you wrote or do we need to find an author to seek appropriate relicensing? (Evidently Artistic 2.0 code can be included like this, but I'd rather go with something simpler as an examplefile that we can clearly say is BSD, if necessary.)
I've renamed the .pm files to .pm6 (I can't get make test to work myself; the test suite seems to take issue with Python 3 being /usr/bin/python). Grammar.pm6 and Optimizer.pm6 are part of the Rakudo codebase under the Artistic 2.0 license; everything else was written by me as examples. We don't need to keep those two files; they just happened to be good examples for testing.