Critique of the IO monad being viewed as a state monad operating on the world

Posted by Petr Pudlák on Programmers See other posts from Programmers or by Petr Pudlák
Published on 2012-08-20T07:33:03Z Indexed on 2012/09/04 15:52 UTC
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Filed under:

functional-programming

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haskell

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io

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monad

The IO monad in Haskell is often explained as a state monad where the state is the world. So a value of type IO a monad is viewed as something like worldState -> (a, worldState).

Some time ago I read an article (or a blog/mailing list post) that criticized this view and gave several reasons why it's not correct. But I cannot remember neither the article nor the reasons. Anybody knows?

Edit: The article seems lost, so let's start gathering various arguments here. I'm starting a bounty to make things more interesting.

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