At a meeting of the Toronto Haskell User Group a few months back (Jan 9, 2013), after going over the basics of the combinatoric parsing library Parsec, I talked about some clever tricks that made my work with it much cleaner. (See also Alber Lai’s write up of his talk, Parsec Generally.)
Note that I don’t have deep knowledge of Parsec. I’ve just used it for a few things and noticed that some code patterns really cleaned up my code. I’d love to hear about other people’s tricks for writing awesome parsers with Parsec!