Newbie ST/Monad Question

[Marcin 'Qrczak' Kowalczyk]

Fri, 24 Aug 2001 11:28:56 -0600, Carl McTague <mctague@one.net> pisze:

>   import ST
> 
>   three :: Int
>   three = runST (do v<-newSTRef 0
> 		    writeSTRef v 3
> 		    readSTRef v)
> 
>   main = print (three*3)
> 
> when this is compiled and run using ghc, it prints
> 
>   carl@exp(monad) ./a.out
>   <<ST action>>

Are you sure? It prints 9 for me.

> what need I do to make it print 6?

Change one of 3's to 2 :-)

-- 
 __("<  Marcin Kowalczyk * qrczak@knm.org.pl http://qrczak.ids.net.pl/
 \__/
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QRCZAK