I have successfully used the the excellent haskell tools Happy and Alex in a couple of parsing projects, but I have failed when trying to combine a monadic Happy grammar (using the %monad and %lexer directives) together with an Alex generated okenizer, nor are there any such examples in the Happy and Alex distributions. Have anyone tried this combination and can give me some advice or a simple example?
I've been doing some work on Alex recently, and getting it to work smoothly with Happy's monadic scheme is one of the goals. I'll post something when it's done, but if you want to have a look at the work-in-progress look in the CVS tree, under fptools/happy/alex on the branch simonm-hackery-branch. The other things I'm doing include making Alex's syntax more lex-like and Happy-like (mostly done), making the generated code more efficient in terms of both space and time (mostly done), and adding support for Unicode (not done, I'm still thinking about how best to do this - I have some ideas but suggestions are welcome). Cheers, Simon