Safe Haskell	None
Language	Haskell2010

Optics.ReversedLens

Contents

Formation
Introduction
Elimination
Computation
Subtyping

Description

A ReversedLens is a backwards Lens , i.e. a ReversedLens s t a b is equivalent to a Lens b a t s . These are typically produced by calling re on a Lens . They are distinguished from a Review so that re . re on a Lens returns a Lens .

Synopsis

type ReversedLens s t a b = Optic A_ReversedLens NoIx s t a b
type ReversedLens' t b = Optic' A_ReversedLens NoIx t b
data A_ReversedLens :: OpticKind

Formation

type ReversedLens s t a b = Optic A_ReversedLens NoIx s t a b Source #

Type synonym for a type-modifying reversed lens.

type ReversedLens' t b = Optic' A_ReversedLens NoIx t b Source #

Type synonym for a type-preserving reversed lens.

Introduction

There is no canonical introduction form for ReversedLens , but you can use re to construct one from a Lens :

(\ f g -> re (lens f g)) :: (b -> t) -> (b -> s -> a) -> ReversedLens s t a b

Elimination

A ReversedLens is a Review , so you can specialise types to obtain:

review :: ReversedLens' s a -> a -> s

There is no corresponding optic kind for a backwards Setter , but a reversed set is definable using re :

set . re :: ReversedLens s t a b -> s -> b -> a

Computation

review   $ re (lens f g) ≡ f
set . re $ re (lens f g) ≡ g

Subtyping

data A_ReversedLens :: OpticKind Source #

Tag for a reversed lens.

Instances

Instances details

ReversibleOptic A_ReversedLens Source #
Instance details Defined in Optics.Re Associated Types type ReversedOptic A_ReversedLens = (r :: Type ) Source # Methods re :: forall (is :: IxList ) s t a b. AcceptsEmptyIndices "re" is => Optic A_ReversedLens is s t a b -> Optic ( ReversedOptic A_ReversedLens ) is b a t s Source #
Is A_ReversedLens A_Review Source #
Instance details Defined in Optics.Internal.Optic.Subtyping Methods implies :: forall (p :: Type -> Type -> Type -> Type ) r. ( Constraints A_ReversedLens p => r) -> Constraints A_Review p => r Source #
Is An_Iso A_ReversedLens Source #
Instance details Defined in Optics.Internal.Optic.Subtyping Methods implies :: forall (p :: Type -> Type -> Type -> Type ) r. ( Constraints An_Iso p => r) -> Constraints A_ReversedLens p => r Source #
k ~ A_Review => JoinKinds A_Review A_ReversedLens k Source #
Instance details Defined in Optics.Internal.Optic.Subtyping Methods joinKinds :: forall (p :: Type -> Type -> Type -> Type ) r. (( Constraints A_Review p, Constraints A_ReversedLens p) => r) -> Constraints k p => r Source #
k ~ A_Review => JoinKinds A_ReversedLens A_Review k Source #
Instance details Defined in Optics.Internal.Optic.Subtyping Methods joinKinds :: forall (p :: Type -> Type -> Type -> Type ) r. (( Constraints A_ReversedLens p, Constraints A_Review p) => r) -> Constraints k p => r Source #
k ~ A_ReversedLens => JoinKinds A_ReversedLens A_ReversedLens k Source #
Instance details Defined in Optics.Internal.Optic.Subtyping Methods joinKinds :: forall (p :: Type -> Type -> Type -> Type ) r. (( Constraints A_ReversedLens p, Constraints A_ReversedLens p) => r) -> Constraints k p => r Source #
k ~ A_Review => JoinKinds A_ReversedLens A_Prism k Source #
Instance details Defined in Optics.Internal.Optic.Subtyping Methods joinKinds :: forall (p :: Type -> Type -> Type -> Type ) r. (( Constraints A_ReversedLens p, Constraints A_Prism p) => r) -> Constraints k p => r Source #
k ~ A_ReversedLens => JoinKinds A_ReversedLens An_Iso k Source #
Instance details Defined in Optics.Internal.Optic.Subtyping Methods joinKinds :: forall (p :: Type -> Type -> Type -> Type ) r. (( Constraints A_ReversedLens p, Constraints An_Iso p) => r) -> Constraints k p => r Source #
k ~ A_Review => JoinKinds A_Prism A_ReversedLens k Source #
Instance details Defined in Optics.Internal.Optic.Subtyping Methods joinKinds :: forall (p :: Type -> Type -> Type -> Type ) r. (( Constraints A_Prism p, Constraints A_ReversedLens p) => r) -> Constraints k p => r Source #
k ~ A_ReversedLens => JoinKinds An_Iso A_ReversedLens k Source #
Instance details Defined in Optics.Internal.Optic.Subtyping Methods joinKinds :: forall (p :: Type -> Type -> Type -> Type ) r. (( Constraints An_Iso p, Constraints A_ReversedLens p) => r) -> Constraints k p => r Source #
( Functor f, f ~ g, s ~ t, a ~ b) => MappingOptic A_ReversedLens f g s t a b Source #
Instance details Defined in Optics.Mapping Associated Types type MappedOptic A_ReversedLens Source # Methods mapping :: forall (is :: IxList ). AcceptsEmptyIndices "mapping" is => Optic A_ReversedLens is s t a b -> Optic ( MappedOptic A_ReversedLens ) is (f s) (g t) (f a) (g b) Source #
type ReversedOptic A_ReversedLens Source #
Instance details Defined in Optics.Re type ReversedOptic A_ReversedLens = A_Lens
type MappedOptic A_ReversedLens Source #
Instance details Defined in Optics.Mapping type MappedOptic A_ReversedLens = A_Review

ReversedLens in the optics hierarchy