You should be weary of using Lex for unicode, because the tables can get large. As far as Bison goes, I guess that's up to you. My preference is against it, ma

You should be weary of using Lex for unicode, because the tables can get large. As far as Bison goes, I guess that's up to you. My preference is against it, mainly because I don't think it buys you much (if the grammar is small, the code for the parser should be small to). The biggest driver should be user experience. If you care a lot about how errors are reported (i.e. you want to avoid cascading errors, while trying to report as many errors as possible up front) , then I say you should definitely not use bison. If you don't care about error reporting much, then its really just based on your personal preference.