http://hackage.haskell.org/trac/ghc/ticket/2392 Make Applicative (in Control.Applicative) a superclass of Monad (in Control.Monad). Rename members of Applicative and other functions, to avoid unnecessary duplication. class Functor f => Applicative f where return :: a -> f a ap :: f (a -> b) -> f a -> f b liftA2 :: Applicative f => (a -> b -> c) -> f a -> f b -> f c liftA2 f a b = ap (fmap f a) b (>>) :: (Applicative f) => f a -> f b -> f b (>>) = liftA2 (const id) -- etc. class Applicative m => Monad m where (>>=) :: m a -> (a -> m b) -> m b fail :: String -> m a fail s = error s I do not have a patch for this change, as it involves mucking around with GHC.Base, and I strongly suspect also fiddling with the GHC source. I'd like to know if it's feasible first. Discussion period: a month? -- Ashley Yakeley