[Haskell-cafe] Re: Tutorial uploaded

Bernard Pope bjpop at csse.unimelb.edu.au
Tue Dec 20 23:21:29 EST 2005

On Tue, 2005-12-20 at 20:58 +0100, Peter Simons wrote:

> Curiously enough, if you check out the reference
> documentation at:
>   http://haskell.org/ghc/docs/latest/html/libraries/base/Control-Monad-ST.html#t%3ARealWorld
> ..., you'll find that a "World" type actually exists.

While that is true in GHC it is not required by Haskell. The concrete
implementation of IO is compiler specific.

Also worth noting is that there are (two that I know of) languages that
employ an explicit world parameter to do IO: Clean and Mercury. 


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