Ashley Yakeley wrote:
http://hackage.haskell.org/trac/ghc/ticket/1773 (darcs patch attached to ticket)
The Compositor class has two members:
class Compositor comp where identity :: comp a a (>>>) :: comp a b -> comp b c -> comp a c
with the obvious monoid. Since all Arrows are Compositors, make
Yes, bring 'em in! But _only_ under their standard name :) class Category c where id :: c a a (.) :: c b c -> c a b -> c a c subject to the well-known laws f = id . f = f . id f . (g . h) = (f . g) . h Who says category theory isn't for functional programmers? ;) Unfortunately, the names id and (.) are already taken / give headache to those that don't like map :: Functor f => (a -> b) -> f a -> f b . Regards, apfelmus