Control.Applicative.Free

Applicative functors for free

Documentation

data Ap f a where

The free Applicative for a Functor f.

Constructors

Pure :: a -> Ap f a

Ap :: f a -> Ap f (a -> b) -> Ap f b

Instances

Functor (Ap f)

Typeable1 f => Typeable1 (Ap f)

Applicative (Ap f)

Apply (Ap f)

runAp :: Applicative g => (forall x. f x -> g x) -> Ap f a -> g a

Given a natural transformation from f to g, this gives a canonical monoidal natural transformation from Ap f to g.

liftAp :: f a -> Ap f a

A version of lift that can be used with just a Functor for f.

hoistAp :: (forall a. f a -> g a) -> Ap f b -> Ap g b

Given a natural transformation from f to g this gives a monoidal natural transformation from Ap f to Ap g.

retractAp :: Applicative f => Ap f a -> f a