[srathbun]

Yes, yes they are. I've used them successfully for various parsing projects. And in fact Bison recently picked up GLR parsing to deal with multiple options (https://www.gnu.org/software/bison/manual/bison.html#General...).

But for something even more fun, I suggest you check out Marpa (https://jeffreykegler.github.io/Marpa-web-site/). It is, by far, the nicest parsing tool I have ever worked with. Being able to parse ANY BNF is huge. And the state tables for debugging! Knowing what possibilities you have makes things way easier. Especially for getting stuck in an ambiguous spot of your grammer. Finally, using ruby slippers to get out of a tight spot is hugely useful.

My one complaint is that the only implementation is in Perl. The core engine is written in C though, so someday I would like to convert the Perl into Python. I started several months ago, and haven't been able to get back to it. (https://github.com/srathbun/pyMarpa)

[srathbun]

Oh, and I found something new and fun for Marpa just now! It seems there's already the beginnings of a Python port (https://github.com/rns/libmarpa-bindings/blob/master/python/...) available.