[Haskell-cafe] Data.Map: Values to keys and keys to values

[Francesco Mazzoli]

On 16/06/11 15:01, Dmitri O.Kondratiev wrote:
> Hi,
> Data.Map has many great functions, yet I could not find the one that
> allows from one map create another map where keys are values and values
> are keys of the first one.
> Something like:
> transMap:: (Ord k, Ord a) => Map k a -> Map a k
>
> Does such function exist?
> Thanks!
>
>
>
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What about something like

transMap :: (Ord k, Ord a) => Map k a -> Map a k
transMap = M.fromList . map swap . M.toList

?

Francesco.