Andy Gill and Simon Marlow have written a parser-generator for Haskell, called `happy'. `Happy' is to Haskell what `Yacc' is to C.
You can get `happy' by FTP from `ftp.dcs.glasgow.ac.uk' in `pub/haskell/happy', the file `happy-0.8.tar.gz'.
`Happy' is at its shining best when compiled by GHC.