Re: [Haskell-cafe] Why no IO transformer monad?

Udo Stenzel wrote:

Keean Schupke schrieb am 20.12.04 14:20:54:

...

Perhaps you would care to explain this then?

Damn, I read a pair parens in there where there was none. The result still stands as is: no transformer version of IO is possible.

But is that beacuse it really isn't (theoretically) possible, or just not possible to write in Haskell (because it would involve new primitives)? Surely if IO is (ST RealWorld a) then (StateT RealWorld m a) is more or less the right thing? Keean.