On Tue, 24 Mar 2009, Xiao-Yong Jin wrote:
Thanks for all the replies. Now I understand more about Exceptions and Errors. I guess all I need is to compose a larger monad, after all. I need to learn how to make two different stacks of monad transformers cooperate seamlessly, though.
Until now it seems you only need Applicative functor. They can be combined in a more general way:
http://hackage.haskell.org/packages/archive/TypeCompose/0.6.4/doc/html/Control-Compose.html See the instances: (Applicative g, Applicative f) => Applicative (g :. f) _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
