How is laziness making ghc slow? Completely strict code doesn't compile any faster, and writing completely lazy ocaml code doesn't compile any slower. How would purity make compilation slower? I want specifics here because it is a specific, factual claim. My opinion on frameworks was left somewhat vague as it is simply my opinion and I had no reason to think anyone wanted more specifics on it. I'm happy to be more specific if you like, what did you want to know?