Control.Lens.Internal.Getter

Documentation

coerce :: (Contravariant f, Functor f) => f a -> f b

A Functor you can coerce ignores its argument, which it carries solely as a phantom type parameter.

By the Functor and Contravariant laws, an instance of both will necessarily satisfy:

id = fmap f = coerce = contramap g

noEffect :: (Contravariant f, Applicative f) => f a

The mempty equivalent for a Contravariant Applicative Functor.

newtype AlongsideLeft f b a

Constructors

AlongsideLeft

Fields

getAlongsideLeft :: f (a, b)

Instances

Functor f => Bifunctor (AlongsideLeft f)

Traversable f => Bitraversable (AlongsideLeft f)

Foldable f => Bifoldable (AlongsideLeft f)

Functor f => Functor (AlongsideLeft f b)

Foldable f => Foldable (AlongsideLeft f b)

Traversable f => Traversable (AlongsideLeft f b)

Contravariant f => Contravariant (AlongsideLeft f b)

Traversable1 f => Traversable1 (AlongsideLeft f b)

Foldable1 f => Foldable1 (AlongsideLeft f b)

Read (f (a, b)) => Read (AlongsideLeft f b a)

Show (f (a, b)) => Show (AlongsideLeft f b a)

newtype AlongsideRight f a b

Constructors

AlongsideRight

Fields

getAlongsideRight :: f (a, b)

Instances

Functor f => Bifunctor (AlongsideRight f)

Traversable f => Bitraversable (AlongsideRight f)

Foldable f => Bifoldable (AlongsideRight f)

Functor f => Functor (AlongsideRight f a)

Foldable f => Foldable (AlongsideRight f a)

Traversable f => Traversable (AlongsideRight f a)

Contravariant f => Contravariant (AlongsideRight f a)

Traversable1 f => Traversable1 (AlongsideRight f a)

Foldable1 f => Foldable1 (AlongsideRight f a)

Read (f (a, b)) => Read (AlongsideRight f a b)

Show (f (a, b)) => Show (AlongsideRight f a b)