All Monads are Functors
taralx at gmail.com
Mon Aug 14 07:34:29 EDT 2006
On 8/14/06, Jon Fairbairn <jon.fairbairn at cl.cam.ac.uk> wrote:
> of course, there's no reason to do that, but what I'm
> proposing is that we allow default instance declarations in
> class declarations in much the same way as default methods:
I just realized that default superclass methods have a small problem:
module A contains instance Monad 
module B contains instance Functor 
module C imports A and B.
Do we complain about a duplicate instance declarations? If not, does
the use of fmap in A use the default definition, or the one from B?
Taral <taralx at gmail.com>
"You can't prove anything."
-- Gödel's Incompetence Theorem
More information about the Haskell-prime