Hello Don, Thursday, August 28, 2008, 10:32:43 AM, you wrote:
Seems like you can make a pure hashtable by unsafePerformIO on the impure one, and exporting only 'lookup'..
probably yes, but it will lose a bit of performance due to incremental building of hashtable. actually, writing HT module from scratch is very easy - all we need is a prime searching function (in order to establish array size). everything else: data HT a b = HT (a->Int) (Array Int [(a,b)]) create size hash list = HT hashfunc (accumArray (flip (:)) [] (0, arrsize-1) (map (\(a,b) -> (hashfunc a,b)) list) ) where arrsize = head$ filter (>size)$ iterate (\x->3*x+1) 1 hashfunc a = hash a `mod` arrsize lookup a (HT hash arr) = List.lookup a (arr!hash a) -- Best regards, Bulat mailto:Bulat.Ziganshin@gmail.com