[achou]

What about performance? I wrote my thesis in OCaml and my recollection was that it had an amazing native code generating compiler that not infrequently output code that was almost as fast as C if you wrote it the right way. The story I heard about Haskell was far different at the time (admittedly decades ago).

[kreetx]

As with all garbage collected languages, optimizing comes down to removing allocations, in Haskell this means strictness and choice of data structures. You can make C-speed programs but you may need to work for it, and you'll also need to know the compiler/evaluation model you're working against.

[achou]

Sure, I think what I noticed was that even idiomatic OCaml code was relatively fast, maybe 2-3x slower than C, but plenty fast enough. Whereas I was under the impression that idiomatic Haskell was far more likely to have unexpected and harder to fix performance issues (e.g. requiring more of an architectural rewrite) because of its lazy evaluation model.