Hello, The only public monads in base that don't have Applicative instances yet are: ReadP, ReadPrec and ArrowMonad. Because of the rule of least surprise I would like to propose adding Applicative instances for these monads. Concretely I would like to propose adding the following to Control.Applicative: instance Applicative ReadP where pure = return (<*>) = ap instance Alternative ReadP where empty = mzero (<|>) = mplus instance Applicative ReadPrec where pure = return (<*>) = ap instance Alternative ReadPrec where empty = mzero (<|>) = mplus instance ArrowApply a => Applicative (ArrowMonad a) where pure = return (<*>) = ap And adding a Functor instance for ArrowMonad to Control.Arrow: instance Arrow a => Functor (ArrowMonad a) where fmap f (ArrowMonad m) = ArrowMonad $ m >>> arr f Discussion deadline: I don't think this is a controversial proposal and so I don't expect objections. Can we bend the rules a bit and shorten the discussion period so this can be integrated into the base library that comes with the upcoming ghc-7.4? Regards, Bas