[Haskell-cafe] Re: Can we come out of a monad?

"Edward Z. Yang" wrote:

Excerpts from Ertugrul Soeylemez's message of Tue Aug 10 02:31:14 -0400 2010:

...

There is no evalCont, there is runCont:

runCont :: (a -> r) -> Cont r a -> r

Note that Cont/ContT computations result in a value of type 'r':

newtype Cont r a = Cont ((a -> r) -> r)

Yes, but if you pass in 'id' as the continuation to 'runCont', the entire expression will result in 'a'. The continuation monad doesn't act globally...

Then you can only run evalCont, if r = a, which makes that function quite pointless: evalCont :: Cont r r -> r evalCont = runCont id Greets, Ertugrul -- nightmare = unsafePerformIO (getWrongWife >>= sex) http://ertes.de/