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

Yes, it works now! thank you very much! Kyle Murphy-2 wrote:

I assume you're trying this at the GHCi prompt, which is where you're problem is coming from, specifically on the first line. When you do:

...

let aaa = unsafePerformIO $ newIORef [] GHCi takes a wild stab at the type of [] and comes up with the type [()], so now you have a IORef [()] type, which is why when you try to store [1,2,3] in the IORef you get back [(),(),()]. Try this instead and it should work: let aaa = unsafePerformIO $ newIORef ([] :: [Int])

-R. Kyle Murphy -- Curiosity was framed, Ignorance killed the cat.

On Thu, Oct 22, 2009 at 01:02, zaxis wrote:

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let aaa = unsafePerformIO $ newIORef [] writeIORef aaa [1,2,3] readIORef aaa [(),(),()]

sincerely! -- View this message in context: http://www.nabble.com/why-cannot-i-get-the-value-of-a-IORef-variable---tp260... Sent from the Haskell - Haskell-Cafe mailing list archive at Nabble.com.

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