Do people actually *use* the MonadCont class? And those who do... do they really use it in a way that would manifest this breakage? basically every existing user of the instance is pretty much guaranteed to
have breakage.
It seems the answer to these questions is "yes" and "yes." I'm curious to
hear more.
-- Dan Burton
On Tue, Jan 20, 2015 at 10:02 AM, Ross Paterson
On Wed, Jan 21, 2015 at 12:09:13AM +1100, Ivan Lazar Miljenovic wrote:
This is what I thought: I just wanted to make sure that I wasn't missing something (especially since there's no real documentation that I could find as to _how_ liftCallCC' fails to satisfy the laws of a monad transformer).
Any lifting of callCC should satisfy
lift (f k) = f' (lift . k) => lift (callCC f) = liftCallCC callCC f'
and liftCallCC' doesn't. _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe