Luke Palmer wrote:
Isn't a type which is both a Monad and a Comonad just Identity?
(I'm actually not sure, I'm just conjecting)
Good idea, but it's not the case.
data L a = One a | Cons a (L a) -- non-empty list
-- standard list monad
instance Monad L where
return = One
Duncan Coutts [EMAIL PROTECTED] writes:
We all know that Functor should have been a superclass of Monad, and
indeed we now know that Applicative should be too. Making such a change
would break lots of things however so the change does not happen.
However in this case the Monad operations can
Jules Bean wrote:
David Menendez wrote:
Duncan Coutts wrote:
So my suggestion is that we let classes declare default
implementations of methods from super-classes.
It creates ambiguity if two classes declare defaults for a common
superclass.
My standard example involves Functor, Monad,
