Add instances for Functor, Monad, Applicative to Data.Monoid.First, Last

Edward Kmett ekmett at
Sat Jun 28 17:17:01 UTC 2014

This proposal made it through its discussion period without adverse
commentary; no real need to go through it all again.

I'd say we should just act upon it. At this point what it needs is a patch.

The core libraries committee has recently approved a similar raft of
missing instances for GHC.Generics.

The general guiding principle is that if there is only one canonical
instance for something that can exist then it should exist. The
alternatives forces people to write orphans that will collide across


On Sat, Jun 28, 2014 at 11:30 AM, Omari Norman <omari at>

> This was proposed in 2011:
> Any reason it did not go anywhere? Should I propose it again?
> Thanks.
> Omari
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> Libraries at
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