25 May
2010
25 May
'10
9:29 a.m.
+1
On Tue, May 25, 2010 at 8:41 AM, Ross Paterson
The proposal is to add this instance to Control.Applicative:
instance Applicative (Either e) where pure = Right Left e <*> _ = Left e Right f <*> r = fmap f r
This is not the only possible instance for Either, but this one is compatible with the usual Monad instance.
Deadline: 15th June 2010 _______________________________________________ Libraries mailing list Libraries@haskell.org http://www.haskell.org/mailman/listinfo/libraries