yacc: type clashes and useless nontermins

Hi

Im trying to write a simple compiler and I'm stuck at the parsing/yacc phase. I keep getting many of these errors and warnings:

• type clash on default action
• empty rule for typed nonterminal
• useless rule

Anyone have any advice on how to tackle these? I attached my lex and yacc output files too incase that helps any.

Thanks

If you get those errors, the rules described by your grammar are ambiguous and incomplete. You should try a progressive approach, by adding one rule at a time, check it works, and resume. Lex/yacc does not support all grammar classes, this is a complex topic and you have to either use a simple grammar or know well what you're doing...