Proposal: Add bifunctor related classes to base

[John Wiegley]

>>>>> Oliver Charles <ollie at ocharles.org.uk> writes:

> While I can't say I've ever reached for Bi* type classes, the argument to
> move people away from Control.Arrow for what is generally Either-specific
> functionality is a strong one. Furthermore, this stuff seems quite common
> (I've seen bifunctors come up in a few papers now).

> +1!

+1

John