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

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.