On 6 September 2010 00:11, Sebastian Fischer <s...@informatik.uni-kiel.de> wrote: >>> Just because we don't have >>> a use now doesn't mean it might not be useful in the future. > > I am suspicious about complicating a design for potential future benefits. > > However, difference lists provide an example of a type that support Pointed > more naturally than Applicative: the dlist package [1] provides Applicative > and Monad instances but only by converting to normal lists in between. > > Note that even fmap cannot be defined without converting difference lists to > normal lists in between. The natural interface to difference lists would be > Pointed (without a Functor superclass) and Monoid.
Hmmm.... is there any reason for Functor to be a superclass of Pointed? I understand Functor and Pointed being superclasses of Applicative (which in turn is a superclass of Monad), but can't see any relation between Pointed and Functor... -- Ivan Lazar Miljenovic ivan.miljeno...@gmail.com IvanMiljenovic.wordpress.com _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
