Re: [Haskell-cafe] Why is Haskell so slow (comparing to Java/Scala)?

Saurabh Nanda writes:

Intresting. Wont using "void" or "_ <- forM blah" have the same effect? Why not?

It has the same behaviour as using forM_, but the performance is worse, as the program still builds the result list before eventually discarding it. Whether this is something that could be optimised away in theory, I'm not sure - but it doesn't seem to be at the moment. Nick