Re: remove a Set of keys from a Map

Hi,

I have (x :: Set key) and (m :: Map key a) and want to remove all keys and corresponding values from m that are in x. I could solve it efficiently with a

differenceSet :: Map key a -> Set key -> Map key a

or with a

Map.fromKeySet :: a -> Set key -> Map key a

or a

Map.fromKeySet :: (key -> a) -> Set key -> Map key a

but I did not find one of these functions in containers-0.4.2.

Map.fromSet :: (key -> a) -> Set key -> Map key a will very likely be available in containers-0.5. Cheers, Milan Straka