Hello Chad, Thursday, July 20, 2006, 9:38:43 PM, you wrote:
> I suppose the same holds for runSTUArray, right? But this still gives > me that same error, about being less polymorphic than expected. there is well-known problem with that _unboxed_ arrays aren't polymorphic. Oleg Kiselyov proposed solution to that problem that i implemented in ArrayRef library (read http://www.haskell.org/pipermail/haskell-cafe/2004-July/006400.html and http://haskell.org/haskellwiki/Library/ArrayRef) this code compiles (i've also fixed pair of other problems): import Data.ArrayBZ.IArray import Data.ArrayBZ.ST (+=) x y = let updateX i = do xi <- readArray x i writeArray x i (xi + y!i) in sequence_ . map updateX $ indices x sumArrays [] = error "Can't apply sumArrays to an empty list" sumArrays (x:xs) = runSTUArray (result x) where result x = do x0 <- thaw x mapM_ (x0 +=) xs return x0 ps: you successfully going through all the standard Haskell troubles in this area :) seems that making FAQ about using ST monad will be a good idea :) -- Best regards, Bulat mailto:[EMAIL PROTECTED] _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
