How can I use Alex as the lexer, then feed the tokens into Parsec for parsing?
Are there any examples?
I think Alex is better (and easier?) to use for lexical analysis than Parsec, but Parsec seems easier than Happy for parsing. They would probably make a good combination.
Yes, you can; see this answers by sinan to a related question, which also links to example code. Others have taken that road as well.