Optics.IxGetter

An IxGetter is an indexed version of a Getter. See the "Indexed optics" section of the overview documentation in the Optics module of the main optics package for more details on indexed optics.

Formation

type IxGetter i s a = Optic' A_Getter (WithIx i) s a

Type synonym for an indexed getter.

Introduction

ito :: (s -> (i, a)) -> IxGetter i s a

Build an indexed getter from a function.

>>> iview (ito id) ('i', 'x')
('i','x')

selfIndex :: IxGetter a a a

Use a value itself as its own index. This is essentially an indexed version of equality.

Elimination

iview :: (Is k A_Getter, is `HasSingleIndex` i) => Optic' k is s a -> s -> (i, a)

View the value pointed to by an indexed getter.

iviews :: (Is k A_Getter, is `HasSingleIndex` i) => Optic' k is s a -> (i -> a -> r) -> s -> r

View the function of the value pointed to by an indexed getter.

Subtyping

data A_Getter :: OpticKind

Tag for a getter.

Instances

ReversibleOptic A_Getter

Defined in Optics.Re

Associated Types

type ReversedOptic A_Getter = (r :: Type)

Methods

re :: AcceptsEmptyIndices "re" is => Optic A_Getter is s t a b -> Optic (ReversedOptic A_Getter) is b a t s

Is A_Getter A_Fold

Defined in Optics.Internal.Optic.Subtyping

Methods

implies :: proxy A_Getter A_Fold p -> (Constraints A_Getter p -> r) -> Constraints A_Fold p -> r

Is A_Getter An_AffineFold

Defined in Optics.Internal.Optic.Subtyping

Methods

implies :: proxy A_Getter An_AffineFold p -> (Constraints A_Getter p -> r) -> Constraints An_AffineFold p -> r

Is A_ReversedPrism A_Getter

Defined in Optics.Internal.Optic.Subtyping

Methods

implies :: proxy A_ReversedPrism A_Getter p -> (Constraints A_ReversedPrism p -> r) -> Constraints A_Getter p -> r

Is A_Lens A_Getter

Defined in Optics.Internal.Optic.Subtyping

Methods

implies :: proxy A_Lens A_Getter p -> (Constraints A_Lens p -> r) -> Constraints A_Getter p -> r

Is An_Iso A_Getter

Defined in Optics.Internal.Optic.Subtyping

Methods

implies :: proxy An_Iso A_Getter p -> (Constraints An_Iso p -> r) -> Constraints A_Getter p -> r

(s ~ t, a ~ b) => ToReadOnly A_Getter s t a b

Defined in Optics.ReadOnly

Methods

getting :: Optic A_Getter is s t a b -> Optic' (Join A_Getter A_Getter) is s a

(s ~ t, a ~ b) => IxOptic A_Getter s t a b

Defined in Optics.Indexed.Core

Methods

noIx :: NonEmptyIndices is => Optic A_Getter is s t a b -> Optic A_Getter NoIx s t a b

type ReversedOptic A_Getter

Defined in Optics.Re

type ReversedOptic A_Getter = A_Review