From: Neil Mitchell
While I'm on the topic, I recently wrote a tool that wanted to traverse deep data structures as produced by haskell-src-exts. ?I wound up with about 50 lines of case expressions and around the time my hands were literally beginning to hurt decided that enough was enough and I should try a generic approach. ?I heard uniplate was pretty easy to use, and was pretty pleased to turn the entire thing into a single line. ?It took me a little longer to figure out I needed to use universeBi since all the examples were monotyped, but once I did it Just Worked. ?Amazing. ?So thanks again! ?And maybe you could mention universeBi in the instant introduction?
Yes, I probably should - I'll try and get to that. Of course, I'd also happily accept a patch against http://community.haskell.org/~ndm/darcs/uniplate
I use Uniplate inside HLint, and it's invaluable - there are a lot of times when List Comp + universeBi really hits the spot.
Does Uniplate include an instance for:
instance Uniplate a => Biplate [a] a ?
Since lists are a common case, I was surprised that this instance wasn't included. Is there a reason it shouldn't exist? I was importing Data.Generics.Uniplate.Direct FWIW. Thanks, John Lato