malcolm

A couple of years ago I had a student doing a project to compare Haskell with Clean for performance. He developed a translator (Hacle) from one language to the other, so the same program could be directly compared for measurement. The initial results were promising - it looked like Clean always produced faster code. But a more careful comparison over more test data showed a mixed picture, some were faster, some slower. Because the languages are so similar (both lazy) this seemed like a good test of one compiler team's skills against another.

So this year, I have a student doing something similar, only with O'Caml and Haskell. Again, there will be a translator from Haskell, and again we are looking to see if Xavier is just a better hacker than SPJ. :-) However, there is more to it this time. To what extent is laziness a time loss, or a time gain? The idea is that there are two possible translations from Haskell to O'Caml - one preserving the structure and semantics of the code, which is then simply evaluated strictly instead of lazily; and the other simulating non-strictness in O'Caml, so the code has the same termination behaviour as well as its semantics. I think everyone would expect O'Caml to win the first challenge, because of its reputation for very fast code. Even so, I suspect there may be cases where laziness is a better strategy, and Haskell might just do well. But how about lazy O'Caml vs lazy Haskell? That's the interesting question for me.