module Applicative
( orAlt
, orEmpty
, eitherA
, liftAA2
, pass
, purer
, (<<*>>)
) where
import Control.Applicative
import Data.Bool (Bool)
import Data.Either (Either (..))
import Data.Function ((.))
import Data.Monoid (Monoid (..))
pass :: Applicative f => f ()
pass = pure ()
orAlt :: (Alternative f, Monoid a) => f a -> f a
orAlt f = f <|> pure mempty
orEmpty :: Alternative f => Bool -> a -> f a
orEmpty b a = if b then pure a else empty
eitherA :: Alternative f => f a -> f b -> f (Either a b)
eitherA a b = (Left <$> a) <|> (Right <$> b)
purer :: (Applicative f, Applicative g) => a -> f (g a)
purer = pure . pure
liftAA2 :: (Applicative f, Applicative g) => (a -> b -> c) -> f (g a) -> f (g b) -> f (g c)
liftAA2 = liftA2 . liftA2
(<<*>>) :: (Applicative f, Applicative g) => f (g (a -> b)) -> f (g a) -> f (g b)
(<<*>>) = liftA2 (<*>)