Re: [Haskell-cafe] instance Applicative f => Applicative (StateT s f)

On Fri, Dec 05, 2008 at 06:56:46PM +0100, Thomas Davie wrote:

Which reminds me ofc, that there is a valid applicative for states (assuming the monad instance is valid):

instance Applicative (StateT s f) where pure = return (<*>) = ap

All monads are also applicatives ;)

Sure, as long as you add the assumption Monad f.