optics-core-0.1: Optics as an abstract interface: core definitions

Safe HaskellNone
LanguageHaskell2010

Optics.IxAffineFold

Contents

Description

An IxAffineFold is an indexed version of an AffineFold. 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

Formation

type IxAffineFold i s a = Optic' An_AffineFold (WithIx i) s a Source #

Type synonym for an indexed affine fold.

Introduction

iafolding :: (s -> Maybe (i, a)) -> IxAffineFold i s a Source #

Create an IxAffineFold from a partial function.

Elimination

ipreview :: (Is k An_AffineFold, is `HasSingleIndex` i) => Optic' k is s a -> s -> Maybe (i, a) Source #

Retrieve the value along with its index targeted by an IxAffineFold.

ipreviews :: (Is k An_AffineFold, is `HasSingleIndex` i) => Optic' k is s a -> (i -> a -> r) -> s -> Maybe r Source #

Retrieve a function of the value and its index targeted by an IxAffineFold.

Computation

ipreview (iafolding f) ≡ f

Semigroup structure

iafailing :: (Is k An_AffineFold, Is l An_AffineFold, is1 `HasSingleIndex` i, is2 `HasSingleIndex` i) => Optic' k is1 s a -> Optic' l is2 s a -> IxAffineFold i s a infixl 3 Source #

Try the first IxAffineFold. If it returns no entry, try the second one.

Note: There is no isumming equivalent, because iasumming = iafailing.

Subtyping

data An_AffineFold Source #

Tag for an affine fold.

Instances
Is An_AffineFold A_Fold Source # 
Instance details

Defined in Optics.Internal.Optic.Subtyping

Is A_Getter An_AffineFold Source # 
Instance details

Defined in Optics.Internal.Optic.Subtyping

Is A_ReversedPrism An_AffineFold Source # 
Instance details

Defined in Optics.Internal.Optic.Subtyping

Is An_AffineTraversal An_AffineFold Source # 
Instance details

Defined in Optics.Internal.Optic.Subtyping

Is A_Prism An_AffineFold Source # 
Instance details

Defined in Optics.Internal.Optic.Subtyping

Is A_Lens An_AffineFold Source # 
Instance details

Defined in Optics.Internal.Optic.Subtyping

Is An_Iso An_AffineFold Source # 
Instance details

Defined in Optics.Internal.Optic.Subtyping

(s ~ t, a ~ b) => ToReadOnly An_AffineFold s t a b Source # 
Instance details

Defined in Optics.ReadOnly

(s ~ t, a ~ b) => IxOptic An_AffineFold s t a b Source # 
Instance details

Defined in Optics.Indexed.Core

Methods

noIx :: NonEmptyIndices is => Optic An_AffineFold is s t a b -> Optic An_AffineFold NoIx s t a b Source #