Optics.ReversedPrism

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

Formation

type ReversedPrism s t a b = Optic A_ReversedPrism NoIx s t a b

Type synonym for a type-modifying reversed prism.

type ReversedPrism' s a = Optic' A_ReversedPrism NoIx s a

Type synonym for a type-preserving reversed prism.

Introduction

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

(\ f g -> re (prism f g)) :: (s -> a) -> (b -> Either a t) -> ReversedPrism s t a b

Elimination

A ReversedPrism is a Getter, so you can specialise types to obtain:

view :: ReversedPrism' s a -> s -> a

There is no reversed matching defined, but it is definable using re:

matching . re :: ReversedPrism s t a b -> b -> Either a t

Computation

view          $ re (prism f g) ≡ f
matching . re $ re (prism f g) ≡ g

Subtyping

data A_ReversedPrism :: OpticKind

Tag for a reversed prism.

Instances

ReversibleOptic A_ReversedPrism

Defined in Optics.Re

Associated Types

type ReversedOptic A_ReversedPrism = (r :: Type)

Methods

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

Is A_ReversedPrism A_Fold

Defined in Optics.Internal.Optic.Subtyping

Methods

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

Is A_ReversedPrism An_AffineFold

Defined in Optics.Internal.Optic.Subtyping

Methods

implies :: proxy A_ReversedPrism An_AffineFold p -> (Constraints A_ReversedPrism 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 An_Iso A_ReversedPrism

Defined in Optics.Internal.Optic.Subtyping

Methods

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

ToReadOnly A_ReversedPrism s t a b

Defined in Optics.ReadOnly

Methods

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

type ReversedOptic A_ReversedPrism

Defined in Optics.Re

type ReversedOptic A_ReversedPrism = A_Prism