On Sun, 2009-01-18 at 11:11 +0000, Andrew Coppin wrote: > Heinrich Apfelmus wrote: > > Andrew Coppin wrote: > > > >>> instance (Monad m) => Functor m where > >>> fmap f ma = do a <- ma; return (f a) > >>> > >>> > >> While that's quite interesting from a mathematical point of view, how is > >> this "useful" for programming purposes? > >> > > > > Surely, you agree that liftM is "useful"? Because that's the same thing. > > > > Then why not just use liftM? (That way, you know what it does...)
I'd be willing to say *you* don't `know what it does', if you haven't figured out that it's an acceptable implementation of fmap first. jcc _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
