It looks ok to me, though I might pattern match in the `where fields` part instead of using `!!`. Still looks pretty good. If I was feeling fancy, that `unlin

It looks ok to me, though I might pattern match in the `where fields` part instead of using `!!`. Still looks pretty good. If I was feeling fancy, that `unlines . map f . lines` looks like an isomorphism that we could do something awesome with the lens library. Anyone who knows it better care to show me how to do that?