When I teach or write about Haskell I try to break down the parts in a way that the parts can be tested using ghci and just composing it at the end. I think th

When I teach or write about Haskell I try to break down the parts in a way that the parts can be tested using ghci and just composing it at the end. I think there are quite a few parts in there that one can easily "try out on their own".