[Haskell-cafe] How to use STArray?
u.stenzel at web.de
Thu Aug 25 13:58:46 EDT 2005
Bayley, Alistair wrote:
> compute :: Int -> Int
> compute n = runST ( do
> arr <- newArray (-1, 1) n
> readArray 1 arr
You messed the argument order to readArray up. Even with that repaired,
you'll need a type signature somewhere to help ghc resolve the
overloading of newArray and readArray, which is surprisingly tricky due
to the "s" that must not escape. This works:
compute :: Int -> Int
compute n = runST ( do
arr <- newArray (-1, 1) n :: ST s (STArray s Int Int)
readArray arr 1
Mikrosoft spel chekar four sail, wurks grate!
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