Re: [Haskell-cafe] Functor and Haskell

Daryoush Mehrtash-2 wrote:

I am not sure I follow how the endofunctor gave me the 2nd functor.

As I read the transformation there are two catagories C and D and two functors F and G between the same two catagories. My problem is that I only have one functor between the Hask and List catagories. So where does the 2nd functor come into picture that also maps between the same C and D catagories?

Consider singleton :: a -> [a] singleton x = [x] Here F is the identity functor, and G is the list functor. And yes, C=D= category of (a subset of) Haskell types. -- View this message in context: http://www.nabble.com/Functor-and-Haskell-tp23166441p23170956.html Sent from the Haskell - Haskell-Cafe mailing list archive at Nabble.com.