14 Jul
2016
14 Jul
'16
11:54 a.m.
On Thu, Jul 14, 2016 at 12:45:27AM -0400, David Feuer wrote:
Cale Gibbard proposes the following:
Data.IntMap.restriction :: IntSet -> IntMap a -> IntMap a Data.Map.restriction :: Ord k => Set k -> Map k a -> Map k a
In each case, the map is filtered to contain only the keys that are also found in the set. This can be implemented efficiently using a slightly stripped-down version of Data.Map.intersection.
One might also want the counterpart of Data.Map.difference for similar reasons.