[Haskell-cafe] map in IO

What is the best way to perform a map inside IO? I defined the following function, but this must be common enough to warrant something in the standard library. What am I missing? -Tom mapIO :: (a -> IO b) -> [a] -> IO [b] mapIO _ [] = return [] mapIO f (x:xs) = do y <- f x ys <- mapIO f xs return (y : ys)