Proposal: merge either into transformers

[Ross Paterson]

On Sat, Apr 26, 2014 at 09:12:12PM +0300, Michael Snoyman wrote:
> I think it's worth resurrecting Gabriel's proposed modification to have the
> strict writer transformer exposed as an abstract type, built on top of StateT
> (or using the same implementation as StateT). I've been bitten by the laziness
> of strict Writer in the past, and thanks to Gabriel's email, I knew how to
> solve the problem. But I think many people will be misled by the name,
> documentation improvements notwithstanding.

Indeed it's a trap.  But an abstract type would be less transparent than
the other transformers, and would be incompatible with the lazy WriterT
in subtle ways.

How about just deprecating strict WriterT in favour of strict StateT?