My friend Eelco wrote his Master's thesis about typesafe diff (and patch) for arbitrary data structures: http://eelco.lempsink.nl/thesis-eelco-lempsink.pdf htt

My friend Eelco wrote his Master's thesis about typesafe diff (and patch) for arbitrary data structures: http://eelco.lempsink.nl/thesis-eelco-lempsink.pdf http://eelco.lempsink.nl/thesis-eelco-lempsink.pdf It allows you to have meaningful diffs for any kind of datastructures, not just lists of strings. The code is also available as a Haskell package: http://hackage.haskell.org/package/gdiff http://hackage.haskell.org/package/gdiff