"S. Alexander Jacobson" writes:

I am not a parsing expert, but given the recent discussion on macros, I have to ask: why use happy rather than monadic parsing? Monadic parsing allows you to avoid a whole additional language/compilation step and work in Hugs (where you don't have a makefile). What does Happy buy you here?

I've used Happy instead of parser combinators because I wanted the additional global error-checking. I believe that the standard implementations of parser combinators will allow you to specify an ambiguous grammar, and return one of the multiple possible parses, without warning. Carl Witty