Proposal: Add modify' to Control.Monad.State.Strict

[Ross Paterson]

On Mon, Apr 28, 2014 at 09:36:02PM +0100, Niklas Hambüchen wrote:
> Code like
> 
>    flip execState 0 (forever $ modify (+1))
> 
> leaks memory as hell, and gets fixed by using
> 
>   x <- get
>   put $! x + 1
> 
> I propose the addition of modify' to Control.Monad.State.Strict.

transformers-0.4 has modify' for both state monads -- it's useful for both.