[Haskell-cafe] why cannot i get the value of a IORef variable ?

[Anton van Straaten]

Colin Paul Adams wrote:
>>>>>> "Gregory" == Gregory Crosswhite <gcross at phys.washington.edu> writes:
> 
>     Gregory> Yes, I was once taught that "Every time you use
>     Gregory> unsafePerformIO, God kills a kitten," so every time I
>     Gregory> consider using it I first ask myself: is this really
>     Gregory> worth an innocent kitten's life?
> 
> I've changed my mind.
> 
> Everyone go out and use unsafePerformIO all the time. That way we can
> get rid of all those mudering kittens, and the dragonflies will live longer.

You're missing the bigger picture.  It's clear from the literature[*] 
that the IO monad, the type system, and possibly even Haskell itself, is 
powered by kittens.  If you use up all the kittens, Haskell will just 
stop working.  Terms won't even reach WHNF, they'll be stuck in KAF, 
Kittenless Abnormal Form.

On the plus side, this does make for a slogan with high market appeal:

    Haskell: Kittens inside

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[*] http://arcanux.org/lambdacats.html