Hello Thomas, Saturday, July 18, 2009, 2:24:21 AM, you wrote:
Further, is there a hashtable implementation for haskell that doesn't live in IO? Maybe in ST or something?
import Prelude hiding (lookup) import qualified Data.HashTable import Data.Array import qualified Data.List as List data HT a b = HT (a->Int) (Array Int [(a,b)]) -- size is the size of array (we implement a closed hash) -- hash is the hash function (a->Int) -- list is assoclist of items to put in hash create size hash list = HT hashfunc (accumArray (flip (:)) [] (0, arrsize-1) (map (\(a,b) -> (hashfunc a,(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) main = do let assoclist = [("one", 1), ("two", 2), ("three", 3)] hash = create 10 (fromEnum . Data.HashTable.hashString) assoclist print (lookup "one" hash) print (lookup "zero" hash) -- Best regards, Bulat mailto:Bulat.Ziganshin@gmail.com