On Dec 11, 2007 3:19 PM, David Menendez <[EMAIL PROTECTED]> wrote: > On Dec 11, 2007 9:20 AM, Duncan Coutts <[EMAIL PROTECTED]> wrote: > > > So my suggestion is that we let classes declare default implementations > > of methods from super-classes. > <snip. > > > Does this proposal have any unintended consequences? I'm not sure. > > Please discuss :-) > > It creates ambiguity if two classes declare defaults for a common > superclass. > > My standard example involves Functor, Monad, and Comonad. Both Monad and > Comonad could provide a default implementation for fmap. But let's say I > have a type which is both a Monad and a Comonad: which default > implementation gets used?
Isn't a type which is both a Monad and a Comonad just Identity? (I'm actually not sure, I'm just conjecting) Luke _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
