While I agree, getting used to that mode of thought takes time. IME you have to write a lot of Haskell (or OCaml) before it becomes a very fast prototyping lang

While I agree, getting used to that mode of thought takes time. IME you have to write a lot of Haskell (or OCaml) before it becomes a very fast prototyping language. Of course, it's 100% worth the investment, and I prefer prototyping in OCaml or Mercury to basically anything else, but it certainly wasn't like that from the first time I picked up OCaml.