[Haskell-cafe] IO and Cont as monads

[Tim Chevalier]

2011/4/12 Burak Ekici <ekcburak at hotmail.com>:
> Dear List,
>
> I am quite new in Haskell's categorical manner of programming. However I
> have enough knowledge in Category Theory.
> I want to ask a question, maybe very well-known one by some of you, about
> monads of Haskell.
>
> For the type constructors like Maybe and [], I managed to prove that
> together with 2 natural transformations (bind + return), both of these
> triples construct a monad. But when I try to prove that IO and Cont type
> constructors with the same natural transformations (bind + return) are
> monads as well, it was failed.
>
> Here my question is: Is there anyone who knows how to prove that IO and Cont
> are monads with satisfing following properties:

IO doesn't obey the monad laws, due to the presence of seq in Haskell.
Sad but true...

Cheers,
Tim



-- 
Tim Chevalier * http://cs.pdx.edu/~tjc/ * Often in error, never in doubt
"an intelligent person fights for lost causes,realizing that others
are merely effects" -- E.E. Cummings