Also, return, ap, liftM, liftM2, .... Already discussed?
On Fri, Jan 30, 2009 at 9:03 AM, Thomas Davie
Hi, Most of Control.Monad doesn't actually rely on Monads, but instead Applicatives. Data.Traversable fixes this in a lot of cases, but it would be nice to have the 'standard' functions as general as possible.
My quick reading of Control.Monad says these at least should fall victim to demotion to applicatives:
mapA :: (Applicative f) => (a -> f b) -> [a] -> f [b] mapA_ :: (Applicative f) => (a -> f b) -> [a] -> f () sequence :: (Applicative f) => [f a] -> f [a] sequence_ :: (Applicative f) => [f a] -> f ()
filterA :: (Applicative f) => (a -> f Bool) -> [a] -> f [a] mapAndUnzipA :: (Applicative f) => (a -> f (b,c)) -> [a] -> f ([b], [c]) zipWithA :: (Applicative f) => (a -> b -> f c) -> [a] -> [b] -> f [c] zipWithA_ :: (Applicative f) => (a -> b -> f c) -> [a] -> [b] -> f () replicateA :: (Applicative f) => Int -> f a -> f [a] replicateA_ :: (Applicative f) => Int -> f a -> f ()
when :: (Applicative f) => Bool -> f () -> f () unless :: (Applicative f) => Bool -> f () -> f ()
I may have missed some.
Bob _______________________________________________ Haskell-prime mailing list Haskell-prime@haskell.org http://www.haskell.org/mailman/listinfo/haskell-prime