Safe Haskell	None
Language	Haskell2010

Optics.IxLens

Contents

Formation
Introduction
Elimination
Additional introduction forms
Subtyping
van Laarhoven encoding

Description

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

Synopsis

type IxLens i s t a b = Optic A_Lens ( WithIx i) s t a b
type IxLens' i s a = Optic' A_Lens ( WithIx i) s a
ilens :: (s -> (i, a)) -> (s -> b -> t) -> IxLens i s t a b
chosen :: IxLens ( Either () ()) ( Either a a) ( Either b b) a b
devoid :: IxLens' i Void a
ifst :: IxLens i (a, i) (b, i) a b
isnd :: IxLens i (i, a) (i, b) a b
data A_Lens :: OpticKind
type IxLensVL i s t a b = forall f. Functor f => (i -> a -> f b) -> s -> f t
type IxLensVL' i s a = IxLensVL i s s a a
ilensVL :: IxLensVL i s t a b -> IxLens i s t a b
toIxLensVL :: ( Is k A_Lens , is `HasSingleIndex` i) => Optic k is s t a b -> IxLensVL i s t a b
withIxLensVL :: ( Is k A_Lens , is `HasSingleIndex` i) => Optic k is s t a b -> ( IxLensVL i s t a b -> r) -> r

Formation

type IxLens i s t a b = Optic A_Lens ( WithIx i) s t a b Source #

Type synonym for a type-modifying indexed lens.

type IxLens' i s a = Optic' A_Lens ( WithIx i) s a Source #

Type synonym for a type-preserving indexed lens.

Introduction

ilens :: (s -> (i, a)) -> (s -> b -> t) -> IxLens i s t a b Source #

Build an indexed lens from a getter and a setter.

If you want to build an IxLens from the van Laarhoven representation, use ilensVL .

Elimination

An IxLens is in particular an IxGetter and an IxSetter , therefore you can specialise types to obtain:

iview :: IxLens i s t a b -> s -> (i, a)

iover :: IxLens i s t a b -> (i -> a -> b) -> s -> t
iset  :: IxLens i s t a b -> (i      -> b) -> s -> t

Additional introduction forms

chosen :: IxLens ( Either () ()) ( Either a a) ( Either b b) a b Source #

Focus on both sides of an Either .

devoid :: IxLens' i Void a Source #

There is an indexed field for every type in the Void .

>>> set (mapped % devoid) 1 []
[]

>>> over (_Just % devoid) abs Nothing
Nothing

ifst :: IxLens i (a, i) (b, i) a b Source #

Indexed _1 with other half of a pair as an index.

See isnd for examples.

Since: 0.4

isnd :: IxLens i (i, a) (i, b) a b Source #

Indexed _2 with other half of a pair as an index. Specialized version of itraversed to pairs, which can be IxLens .

>>> iview isnd ('a', True)
('a',True)

That is not possible with itraversed , because it is an IxTraversal .

>>> :t itraversed :: IxTraversal i (i, a) (i, b) a b
itraversed :: IxTraversal i (i, a) (i, b) a b
  :: IxTraversal i (i, a) (i, b) a b

Since: 0.4

Subtyping

data A_Lens :: OpticKind Source #

Tag for a lens.

Instances

Instances details

ReversibleOptic A_Lens Source #
Instance details Defined in Optics.Re Associated Types type ReversedOptic A_Lens = (r :: Type ) Source # Methods re :: forall (is :: IxList ) s t a b. AcceptsEmptyIndices "re" is => Optic A_Lens is s t a b -> Optic ( ReversedOptic A_Lens ) is b a t s Source #
Is A_Lens A_Fold Source #
Instance details Defined in Optics.Internal.Optic.Subtyping Methods implies :: forall (p :: Type -> Type -> Type -> Type ) r. ( Constraints A_Lens p => r) -> Constraints A_Fold p => r Source #
Is A_Lens An_AffineFold Source #
Instance details Defined in Optics.Internal.Optic.Subtyping Methods implies :: forall (p :: Type -> Type -> Type -> Type ) r. ( Constraints A_Lens p => r) -> Constraints An_AffineFold p => r Source #
Is A_Lens A_Getter Source #
Instance details Defined in Optics.Internal.Optic.Subtyping Methods implies :: forall (p :: Type -> Type -> Type -> Type ) r. ( Constraints A_Lens p => r) -> Constraints A_Getter p => r Source #
Is A_Lens A_Setter Source #
Instance details Defined in Optics.Internal.Optic.Subtyping Methods implies :: forall (p :: Type -> Type -> Type -> Type ) r. ( Constraints A_Lens p => r) -> Constraints A_Setter p => r Source #
Is A_Lens A_Traversal Source #
Instance details Defined in Optics.Internal.Optic.Subtyping Methods implies :: forall (p :: Type -> Type -> Type -> Type ) r. ( Constraints A_Lens p => r) -> Constraints A_Traversal p => r Source #
Is A_Lens An_AffineTraversal Source #
Instance details Defined in Optics.Internal.Optic.Subtyping Methods implies :: forall (p :: Type -> Type -> Type -> Type ) r. ( Constraints A_Lens p => r) -> Constraints An_AffineTraversal p => r Source #
Is An_Iso A_Lens 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_Lens p => r Source #
Arrow arr => ArrowOptic A_Lens arr Source #
Instance details Defined in Optics.Arrow Methods overA :: forall (is :: IxList ) s t a b. Optic A_Lens is s t a b -> arr a b -> arr s t Source #
k ~ A_Fold => JoinKinds A_Fold A_Lens k Source #
Instance details Defined in Optics.Internal.Optic.Subtyping Methods joinKinds :: forall (p :: Type -> Type -> Type -> Type ) r. (( Constraints A_Fold p, Constraints A_Lens p) => r) -> Constraints k p => r Source #
k ~ An_AffineFold => JoinKinds An_AffineFold A_Lens k Source #
Instance details Defined in Optics.Internal.Optic.Subtyping Methods joinKinds :: forall (p :: Type -> Type -> Type -> Type ) r. (( Constraints An_AffineFold p, Constraints A_Lens p) => r) -> Constraints k p => r Source #
k ~ A_Getter => JoinKinds A_Getter A_Lens k Source #
Instance details Defined in Optics.Internal.Optic.Subtyping Methods joinKinds :: forall (p :: Type -> Type -> Type -> Type ) r. (( Constraints A_Getter p, Constraints A_Lens p) => r) -> Constraints k p => r Source #
k ~ A_Getter => JoinKinds A_ReversedPrism A_Lens k Source #
Instance details Defined in Optics.Internal.Optic.Subtyping Methods joinKinds :: forall (p :: Type -> Type -> Type -> Type ) r. (( Constraints A_ReversedPrism p, Constraints A_Lens p) => r) -> Constraints k p => r Source #
k ~ A_Setter => JoinKinds A_Setter A_Lens k Source #
Instance details Defined in Optics.Internal.Optic.Subtyping Methods joinKinds :: forall (p :: Type -> Type -> Type -> Type ) r. (( Constraints A_Setter p, Constraints A_Lens p) => r) -> Constraints k p => r Source #
k ~ A_Traversal => JoinKinds A_Traversal A_Lens k Source #
Instance details Defined in Optics.Internal.Optic.Subtyping Methods joinKinds :: forall (p :: Type -> Type -> Type -> Type ) r. (( Constraints A_Traversal p, Constraints A_Lens p) => r) -> Constraints k p => r Source #
k ~ An_AffineTraversal => JoinKinds An_AffineTraversal A_Lens k Source #
Instance details Defined in Optics.Internal.Optic.Subtyping Methods joinKinds :: forall (p :: Type -> Type -> Type -> Type ) r. (( Constraints An_AffineTraversal p, Constraints A_Lens p) => r) -> Constraints k p => r Source #
k ~ An_AffineTraversal => JoinKinds A_Prism A_Lens 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_Lens p) => r) -> Constraints k p => r Source #
k ~ A_Fold => JoinKinds A_Lens A_Fold k Source #
Instance details Defined in Optics.Internal.Optic.Subtyping Methods joinKinds :: forall (p :: Type -> Type -> Type -> Type ) r. (( Constraints A_Lens p, Constraints A_Fold p) => r) -> Constraints k p => r Source #
k ~ An_AffineFold => JoinKinds A_Lens An_AffineFold k Source #
Instance details Defined in Optics.Internal.Optic.Subtyping Methods joinKinds :: forall (p :: Type -> Type -> Type -> Type ) r. (( Constraints A_Lens p, Constraints An_AffineFold p) => r) -> Constraints k p => r Source #
k ~ A_Getter => JoinKinds A_Lens A_Getter k Source #
Instance details Defined in Optics.Internal.Optic.Subtyping Methods joinKinds :: forall (p :: Type -> Type -> Type -> Type ) r. (( Constraints A_Lens p, Constraints A_Getter p) => r) -> Constraints k p => r Source #
k ~ A_Getter => JoinKinds A_Lens A_ReversedPrism k Source #
Instance details Defined in Optics.Internal.Optic.Subtyping Methods joinKinds :: forall (p :: Type -> Type -> Type -> Type ) r. (( Constraints A_Lens p, Constraints A_ReversedPrism p) => r) -> Constraints k p => r Source #
k ~ A_Setter => JoinKinds A_Lens A_Setter k Source #
Instance details Defined in Optics.Internal.Optic.Subtyping Methods joinKinds :: forall (p :: Type -> Type -> Type -> Type ) r. (( Constraints A_Lens p, Constraints A_Setter p) => r) -> Constraints k p => r Source #
k ~ A_Traversal => JoinKinds A_Lens A_Traversal k Source #
Instance details Defined in Optics.Internal.Optic.Subtyping Methods joinKinds :: forall (p :: Type -> Type -> Type -> Type ) r. (( Constraints A_Lens p, Constraints A_Traversal p) => r) -> Constraints k p => r Source #
k ~ An_AffineTraversal => JoinKinds A_Lens An_AffineTraversal k Source #
Instance details Defined in Optics.Internal.Optic.Subtyping Methods joinKinds :: forall (p :: Type -> Type -> Type -> Type ) r. (( Constraints A_Lens p, Constraints An_AffineTraversal p) => r) -> Constraints k p => r Source #
k ~ An_AffineTraversal => JoinKinds A_Lens A_Prism k Source #
Instance details Defined in Optics.Internal.Optic.Subtyping Methods joinKinds :: forall (p :: Type -> Type -> Type -> Type ) r. (( Constraints A_Lens p, Constraints A_Prism p) => r) -> Constraints k p => r Source #
k ~ A_Lens => JoinKinds A_Lens A_Lens k Source #
Instance details Defined in Optics.Internal.Optic.Subtyping Methods joinKinds :: forall (p :: Type -> Type -> Type -> Type ) r. (( Constraints A_Lens p, Constraints A_Lens p) => r) -> Constraints k p => r Source #
k ~ A_Lens => JoinKinds A_Lens An_Iso k Source #
Instance details Defined in Optics.Internal.Optic.Subtyping Methods joinKinds :: forall (p :: Type -> Type -> Type -> Type ) r. (( Constraints A_Lens p, Constraints An_Iso p) => r) -> Constraints k p => r Source #
k ~ A_Lens => JoinKinds An_Iso A_Lens 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_Lens p) => r) -> Constraints k p => r Source #
ToReadOnly A_Lens s t a b Source #
Instance details Defined in Optics.ReadOnly Associated Types type ReadOnlyOptic A_Lens Source # Methods getting :: forall (is :: IxList ). Optic A_Lens is s t a b -> Optic' ( ReadOnlyOptic A_Lens ) is s a Source #
IxOptic A_Lens s t a b Source #
Instance details Defined in Optics.Indexed.Core Methods noIx :: forall (is :: IxList ). NonEmptyIndices is => Optic A_Lens is s t a b -> Optic A_Lens NoIx s t a b Source #
( Functor f, f ~ g, s ~ t, a ~ b) => MappingOptic A_Lens f g s t a b Source #
Instance details Defined in Optics.Mapping Associated Types type MappedOptic A_Lens Source # Methods mapping :: forall (is :: IxList ). AcceptsEmptyIndices "mapping" is => Optic A_Lens is s t a b -> Optic ( MappedOptic A_Lens ) is (f s) (g t) (f a) (g b) Source #
type ReversedOptic A_Lens Source #
Instance details Defined in Optics.Re type ReversedOptic A_Lens = A_ReversedLens
type ReadOnlyOptic A_Lens Source #
Instance details Defined in Optics.ReadOnly type ReadOnlyOptic A_Lens = A_Getter
type MappedOptic A_Lens Source #
Instance details Defined in Optics.Mapping type MappedOptic A_Lens = A_Getter

van Laarhoven encoding

type IxLensVL i s t a b = forall f. Functor f => (i -> a -> f b) -> s -> f t Source #

Type synonym for a type-modifying van Laarhoven indexed lens.

type IxLensVL' i s a = IxLensVL i s s a a Source #

Type synonym for a type-preserving van Laarhoven indexed lens.

ilensVL :: IxLensVL i s t a b -> IxLens i s t a b Source #

Build an indexed lens from the van Laarhoven representation.

toIxLensVL :: ( Is k A_Lens , is `HasSingleIndex` i) => Optic k is s t a b -> IxLensVL i s t a b Source #

Convert an indexed lens to its van Laarhoven representation.

withIxLensVL :: ( Is k A_Lens , is `HasSingleIndex` i) => Optic k is s t a b -> ( IxLensVL i s t a b -> r) -> r Source #

Work with an indexed lens in the van Laarhoven representation.