difference between (evaluate . runST) and stToIO

[Hal Daume III]

I can't seem to figure out what the difference is between using

  evaluate (runST action)

and

  stToIO action

when in the IO monad and running something in ST...they seem to behave
identically...are they?

If they are, why do they have different type signatures (one is ST
RealWorld a -> IO a, while the other is (forall s. ST s a) -> IO a)?

 - Hal

--
Hal Daume III

 "Computer science is no more about computers    | hdaume@isi.edu
  than astronomy is about telescopes." -Dijkstra | www.isi.edu/~hdaume