[Haskell-cafe] Prettier pretty-printing of data types?

Hi all, The derived Show instance is useful, but I sometimes wish for something that's easier to read for big data types. Does anyone have an implementation of show that draws things in a hierarchical manner? Example: Given data Tree a = Leaf | Bin Int a (Tree a) (Tree a) and value = Bin 1 (Bin 2 Leaf Leaf) (Bin 3 Leaf Leaf) draw as Bin 1 Bin 2 Leaf Leaf Bin 3 Leaf Leaf Cheers, Johan