13 Aug
2009
13 Aug
'09
12:10 a.m.
Dan Doel wrote:
On Wednesday 12 August 2009 11:46:29 pm Ben Lippmeier wrote:
Dan Doel wrote:
Off hand, I'd say I don't write foo and fooM versions of functions much in actual programs, either. Such duplication goes into libraries...
It would be ok if the duplication /was/ actually in the libraries, but often it's not.
Note the lack of Data.Map.mapM and Data.Map.foldM. Want to apply a monadic computation to all the elements of a Data.Map? Convert it to a list and back..
Or use Data.Traversable.mapM and Data.Foldable.foldM.
Ah thanks, I didn't notice the Traversable instance. There are other higher-order functions in Data.Map that don't seem to have monadic counterparts though, like insertWith, unionsWith, updateAt ... Ben.