[Haskell-cafe] Why no IO transformer monad?
Benjamin.Rudiak-Gould at cl.cam.ac.uk
Mon Dec 20 11:19:27 EST 2004
Ross Paterson wrote:
>But IO is not ST RealWorld (even if GHC pretends it is): other users
>of the world are not waiting for the new world produced by your Haskell
They're *part* of the world. IO = State RealWorld makes sense if you
think of RealWorld as encapsulating the entire state of the universe,
including "other users".
The only trouble is that concurrent processes end up containing each
other. I'm not entirely convinced that this can't be solved with some
sort of fixed-point trick.
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