Data.Monoid.First and Data.Monoid.Last

[Sterling Clover]

On Jan 9, 2011, at 3:34 PM, Louis Wasserman wrote:

> Is there a reason that Data.Monoid.First and Data.Monoid.Last aren't also instances of Functor, Applicative, Alternative, Monad, MonadPlus?  I find those instances quite useful.

Funny you should mention that. I have a current proposal (deadline Jan 20) to add those instances:
http://www.haskell.org/pipermail/libraries/2011-January/015552.html

Ticket: http://hackage.haskell.org/trac/ghc/ticket/4880

The proposal didn't deal with Alternative and MonadPlus, but now that it's been pointed out (twice) I absolutely agree that they should be added as well.

Cheers,
Sterl