[Haskell-cafe] Re: Modelling a mutable variable store

Stefan O'Rear stefanor at cox.net
Sat Dec 1 23:48:51 EST 2007


On Sun, Dec 02, 2007 at 03:54:05AM +0000, Kannan Goundan wrote:
> On Sat, 01 Dec 2007 21:22:53 -0600, Derek Elkins wrote:
> 
> > Use ST.  First-class state isn't too great unless you specifically want
> > that.
> 
> I did try using ST but ran into a problem because its type variable (s) 
> ended up invading all of my types.

That's just ST ugliness, the price you have to pay for a pure runST.  If
you're doing almost everything in ST, it can be cleaner just to use
IORefs.

Stefan
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