Question

I’m looking for a Haskell compiler that uses strict evaluation by default instead of lazy evaluation. I would just use OCaml, but Haskell’s syntax is so much better than OCaml’s (and Haskell is pure, and has cool features such as type classes).

I’d really rather not constantly put !s and $!s all over my program. A compiler with a switch or a preprocessor to put in the strictness annotations would be really nice. It would also be helpful if there was a way to use lazy evaluation in certain places too, just in case I want something like an infinite list (I probably never will).

Please do not try to convince me that lazy evaluation is better, I really need the performance. IIRC, Simon Peyton Jones even said that lazy evaluation wasn’t really necessary, it was there mostly to prevent them from making the language impure.

Answer 1

If you have a Haskell compiler that uses strict evaluation, it doesn’t compile Haskell. Laziness Non-strictness is part of the Haskell spec!

However, there are alternatives.

• DDC is an attempt to create an explicitly lazy variant of Haskell which supports things like destructive update whilst retaining all the rest of Haskell’s goodness. There is one problem: the compiler is currently only in the α-stage, although it seems to be at least usable.

• Create a preprocessor, as others have done.

• Learn to use Haskell “the right way”. If you can simplify your test case down to something which is publicly-displayable, you could post it on the Haskell-Café mailing list, where people are very helpful with these sorts of questions concerning the effects of non-strictness.