See also the paper "Idioms are oblivious, arrows are meticulous, monads are promiscuous" [1]. Functors can be extended to give applicative functors (idioms) which can then be extended to arrows, and then monads. So all arrows are also (applicative) functors.
[1]: http://homepages.inf.ed.ac.uk/wadler/papers/arrows-and-idioms/arrows-and-idioms.pdf _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
