On Tue, May 25, 2010 at 8:41 AM, Ross Paterson <ross@soi.city.ac.uk> wrote:

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