[Haskell-cafe] Re: Referential Transparency and Monads

[Jonathan Cast]

On Fri, 2009-04-10 at 00:46 -0400, Brandon S. Allbery KF8NH wrote:
> On 2009 Apr 10, at 0:33, Heinrich Apfelmus wrote:
> > Luke Palmer wrote:
> >> Miguel Mitrofanov wrote:
> >>
> >>> I'm not sure what you mean by that, but semantically IO is  
> >>> definitely
> >>>> *not* a state monad.  Under any circumstances or any set of  
> >>>> assumptions.
> >>>>
> >>> Ehm? Why not?
> >>
> >> Mainly forkIO.  There may be other reasons.
> >  loop' :: IO ()
> >  loop' = putStr "o" >> loop'
> >
> > are indistinguishable in the
> >
> >  IO a  ~  World -> (a, World)
> 
> 
> I still don't understand this; we are passing a World and getting a  
> World back,

We are?  Why do you think that?

jcc