(Sorry for the double mail)
...so there is no way to do that inside the function passed to modifySTRef?
In other words, there is no way to ensure *inside* a function that its result will be evaluated strictly?

2011/11/18 Daniel Fischer <daniel.is.fischer@googlemail.com>
On Friday 18 November 2011, 11:18:33, Yves Parès wrote:
> Instead of rewriting modifySTRef, why not just do :
>
> modifySTRef counter (\x -> let y = x+1 in y `seq` y)
>
> Is there a problem with that?

Yes, y `seq` y is precisely the same as y.

a `seq` b means whenever evaluation of b is demanded, also evaluate a (to
WHNF).
So y `seq` y ~> whenever evaluation of y is demanded, also evaluate y.