On Mon, 14 Feb 2005 10:07:41 -0500, Jacques Carette <[EMAIL PROTECTED]> wrote: > Josef Svenningsson <[EMAIL PROTECTED]> wrote: > > You claimed that monad transformers break the > > mzero-is-right-identity-for-bind law because they can be applied to > > IO. I say, it's not the monad transformers fault. They cannot possibly > > be expected to repair the law if they are given a faulty monad. > > Doesn't that argue for allowing proven and unproven Monads in Haskell? > I believe you misunderstand me. The point that I was trying to make was about monad transformers. I was saying that the best they can do with respect to a law is to preserve it, which I believe all monad transformers should do. Otherwise they don't deserve the name.
Turning to monad they should certainly fulfil the laws we associate with a monad. Otherwise they wouldn't be monads! I am not proposing or encouraging that one should declare a data type an instance of monad if they do not obey the monad laws. Cheers, /Josef _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
