{-# LANGUAGE DeriveGeneric #-} import Text.PrettyPrint.GenericPretty import Text.PrettyPrint data Tree a = Leaf a | Node (Tree a) (Tree a) deriving (Generic) instance (Out a) => Out (Tree a) tree1 :: Tree Int tree1 = Node (Node (Leaf 333333) (Leaf (-555555)))(Node (Node(Node(Leaf 888888) (Leaf 57575757))(Leaf (-14141414)))(Leaf 7777777)) zigStyle :: Style zigStyle = Style {mode = ZigZagMode, lineLength = 30, ribbonsPerLine = 1.5} main = ppStyle zigStyle tree1