On Feb 2, 2009, at 1:06 AM, Louis Wasserman wrote:
Is there any sensible way to make
newtype FooT m e = FooT (StateT Bar m e) deriving (MonadState)
work to give instance MonadState Bar (FooT m e)?
That is, I'm asking if there would be a semantically sensible way of modifying GeneralizedNewtypeDeriving to handle multi-parameter type classes when there is a functional dependency involved, assuming by default that the newtype is the more general of the types, perhaps?
Louis Wasserman wasserman.louis@gmail.com _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
did you try this? newtype FooT m e = FooT (StateT Bar m e) deriving (Monad, MonadState Bar)