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. _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
