On Thu, Jun 16, 2011 at 5:38 PM, Johan Tibell <[email protected]>wrote:

> On Thu, Jun 16, 2011 at 3:01 PM, Dmitri O.Kondratiev <[email protected]>
> 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
>
> I don't think implementing this function in the library would add much
> as it cannot be implemented more efficiently with access to the
> internal representation than it can using the public API. Just write
>
>    transMap = M.fromList . map swap . M.toList
>
> and stick it in some utility file.
>
> Johan
>


Yes, this is a good one. Thanks!
_______________________________________________
Haskell-Cafe mailing list
[email protected]
http://www.haskell.org/mailman/listinfo/haskell-cafe

Reply via email to