RE: Proposal: Add Applicative instances for the remaining monads in base

We also seem to be missing instance ArrowPlus a => Alternative (ArrowMonad a) where empty = ArrowMonad zeroArrow ArrowMonad x <|> ArrowMonad y = ArrowMonad (x <+> y) instance (ArrowApply a, ArrowPlus a) => MonadPlus (ArrowMonad a) where mzero = ArrowMonad zeroArrow ArrowMonad x `mplus` ArrowMonad y = ArrowMonad (x <+> y)