Re: Proposal: Add `restriction` to Data.Map and Data.IntMap

On 14 July 2016 at 14:45, 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.

+1 I've bodged up similar things in the past, so this would be appreciated. -- Ivan Lazar Miljenovic Ivan.Miljenovic@gmail.com http://IvanMiljenovic.wordpress.com