Claus Reinke wrote:
Do you have an example of a mutable state/ IO bound application, like, hmm, a window manager or a revision control system or a file system...?
If you're looking for a challenge, how about this one (there used to be lots of Haskellers into this game, any of you still around?-):
http://computer-go.org/pipermail/computer-go/2008-October/016680.html
[ catching up with old haskell-cafe email ] Interestingly, I did this a while ago. Here's my results: $ ./Bench 1 100000 b: 14840, w: 17143 mercy: 67982 elapsed time: 3.42s playouts/sec: 29208 so, nearly 30k/sec random playouts on 9x9. That's using a hack that stops the game when the score is heavily in favour of one player, it drops to around 20k/sec with that turned off. Not bad, but probably I'd guess an order of magnitude worse than you can do in tightly-coded C. The Haskell implementation isn't nice, as you predicted. Also the code is derived from some non-free internal MS code, so unfortunately I can't share it (but I could perhaps extract the free bits if anyone is really interested). W wins slightly more often I think because komi 5.5 on a 9x9 board is a tad high. It does parallelise too, of course: $ ./Bench 8 100000 +RTS -N8 b: 14872, w: 17488 mercy: 67584 elapsed time: 1.00s playouts/sec: 99908 though still room for improvement there. Cheers, Simon