Some years ago, Ralf Hinze wrote this parser generator [0], and i have since been using it, so i cleaned it up and uploaded it to Hackage as "frown" [1]. My repo is here: https://github.com/strake/frown [0] http://www.cs.ox.ac.uk/ralf.hinze/frown/ [1] https://hackage.haskell.org/package/frown