CSE is tricky and a potential space leak in general. I'd love it if the compiler could pick the best option, but I'm afraid its unlikely to know.
On Thu, Mar 19, 2009 at 4:25 PM, Edsko de Vries <devri...@cs.tcd.ie> wrote: > I always feel that the compiler should do such optimizations for me :) > On 19 Mar 2009, at 16:21, Neil Mitchell wrote: > >>> I've used a similar function myself, but why write it in such a >>> complicated >>> way? How about >>> >>> lfp :: Eq a => (a -> a) -> a -> a >>> lfp f x >>> | f x == x = x >>> | otherwise = lfp f (f x) >> >> I've used a similar function too, but your version computes f x twice >> per iteration, I wrote mine as: >> >> fix :: Eq a => (a -> a) -> a -> a >> fix f x = if x == x2 then x else fix f x2 >> where x2 = f x >> >> I find this fix much more useful than the standard fix. >> >> Thanks >> >> Neil > > _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
