Data.Lens.Getter

Operator alias for Data.Lens.Getter.viewOn (left-associative / precedence 8)

view :: forall b a t s. Getter s t a b -> s -> a

View the focus of a Getter.

iview :: forall b a t s i. IndexedFold (Tuple i a) i s t a b -> s -> Tuple i a

View the focus of a Getter and its index.

viewOn :: forall b a t s. s -> Getter s t a b -> a

Synonym for view, flipped.

to :: forall b a t s r. (s -> a) -> Fold r s t a b

Convert a function into a getter.

takeBoth :: forall d c b a t s. Getter s t a b -> Getter s t c d -> Getter s t (Tuple a c) (Tuple b d)

Combine two getters.

use :: forall m b a t s. MonadState s m => Getter s t a b -> m a

View the focus of a Getter in the state of a monad.

iuse :: forall m b a t s i. MonadState s m => IndexedFold (Tuple i a) i s t a b -> m (Tuple i a)

View the focus of a Getter and its index in the state of a monad.

type Optic p s t a b = p a b -> p s t

A general-purpose Data.Lens.

type IndexedGetter i s t a b = IndexedFold a i s t a b

An indexed getter.

type IndexedFold r i s t a b = IndexedOptic (Forget r) i s t a b

An indexed fold.

newtype Indexed p i s t

Profunctor used for IndexedOptics.

Constructors

• Indexed (p (Tuple i s) t)

Instances

• Newtype (Indexed p i s t) _
• (Profunctor p) => Profunctor (Indexed p i)
• (Strong p) => Strong (Indexed p i)
• (Choice p) => Choice (Indexed p i)
• (Wander p) => Wander (Indexed p i)

type Getter s t a b = Fold a s t a b

A getter.

type Fold r s t a b = Optic (Forget r) s t a b

A fold.