arrow-optics / arrow.optics / PLens

PLens

interface PLens<S, T, A, B> : PLensOf<S, T, A, B>

A Lens (or Functional Reference) is an optic that can focus into a structure for getting, setting or modifying the focus (target).

A (polymorphic) PLens is useful when setting or modifying a value for a constructed type i.e. PLens<Tuple2<Double, Int>, Tuple2<String, Int>, Double, String>

A PLens can be seen as a pair of functions:

• get: (S) -> A meaning we can focus into an S and extract an A
• set: (B) -> (S) -> T meaning we can focus into an S and set a value B for a target A and obtain a modified source T

Parameters

S - the source of a PLens

T - the modified source of a PLens

A - the focus of a PLens

B - the modified focus of a PLens

Functions

| asFold | View a PLens as a Foldopen fun asFold(): Fold<S, A> | | asGetter | View PLens as a Getteropen fun asGetter(): Getter<S, A> | | asOptional | View a PLens as a POptionalopen fun asOptional(): POptional<S, T, A, B> | | asSetter | View a PLens as a PSetteropen fun asSetter(): PSetter<S, T, A, B> | | asTraversal | View a PLens as a PTraversalopen fun asTraversal(): PTraversal<S, T, A, B> | | choice | Join two PLens with the same focus in Aopen infix fun <S1, T1> choice(other: PLens<S1, T1, A, B>): PLens<Either<S, S1>, Either<T, T1>, A, B> | | compose | Compose a PLens with another PLensopen infix fun <C, D> compose(l: PLens<A, B, C, D>): PLens<S, T, C, D>
Compose a PLens with a POptionalopen infix fun <C, D> compose(other: POptional<A, B, C, D>): POptional<S, T, C, D>
Compose an PLens with a PIsoopen infix fun <C, D> compose(other: PIso<A, B, C, D>): PLens<S, T, C, D>
Compose an PLens with a Getteropen infix fun <C> compose(other: Getter<A, C>): Getter<S, C>
Compose an PLens with a PSetteropen infix fun <C, D> compose(other: PSetter<A, B, C, D>): PSetter<S, T, C, D>
Compose an PLens with a PPrismopen infix fun <C, D> compose(other: PPrism<A, B, C, D>): POptional<S, T, C, D>
Compose an PLens with a Foldopen infix fun <C> compose(other: Fold<A, C>): Fold<S, C>
Compose an PLens with a PTraversalopen infix fun <C, D> compose(other: PTraversal<A, B, C, D>): PTraversal<S, T, C, D> | | exist | Verify if the focus of a PLens satisfies the predicateopen fun exist(s: S, p: (A) -> Boolean): Boolean | | find | Find a focus that satisfies the predicateopen fun find(s: S, p: (A) -> Boolean): Option<A> | | first | Create a product of the PLens and a type Copen fun <C> first(): PLens<Tuple2<S, C>, Tuple2<T, C>, Tuple2<A, C>, Tuple2<B, C>> | | get | abstract fun get(s: S): A | | lift | Lift a function f: (A) -> B to the context of S: (S) -> Topen fun lift(f: (A) -> B): (S) -> T` | | [liftF](lift-f.html) | Lift a function [f](lift-f.html#arrow.optics.PLens$liftF(arrow.typeclasses.Functor((arrow.optics.PLens.liftF.F)), kotlin.Function1((arrow.optics.PLens.A, arrow.Kind((arrow.optics.PLens.liftF.F, arrow.optics.PLens.B)))))/f): `(A) -> Kind<F, B> to the context of `S`: `(S) -&gt; Kind&lt;F, T&gt;open fun liftF(FF: Functor, f: (A) -> Kind<F, B>): (S) -> Kind<F, T>` | | [modify](modify.html) | Modify the focus of s [PLens](./index.html) using s function `(A) -> B``open fun modify(s: S, f: (A) -> B): T` | | [modifyF](modify-f.html) | Modify the focus of a [PLens](./index.html) using Functor function`open fun modifyF(FF: Functor, s: S, f: (A) -> Kind<F, B>): Kind<F, T>` | | [plus](plus.html) | Plus operator overload to compose lenses`open operator fun <C, D> plus(other: `[`PLens`](./index.html)`<A, B, C, D>): `[`PLens`](./index.html)`<S, T, C, D>``open operator fun <C, D> plus(other: `[`POptional`](../-p-optional/index.html)`<A, B, C, D>): `[`POptional`](../-p-optional/index.html)`<S, T, C, D>`
`open operator fun <C, D> plus(other: `[`PIso`](../-p-iso/index.html)`<A, B, C, D>): `[`PLens`](./index.html)`<S, T, C, D>`
`open operator fun plus(other: `[`Getter`](../-getter/index.html)`<A, C>): `[`Getter`](../-getter/index.html)`<S, C>`
`open operator fun <C, D> plus(other: `[`PSetter`](../-p-setter/index.html)`<A, B, C, D>): `[`PSetter`](../-p-setter/index.html)`<S, T, C, D>`
`open operator fun <C, D> plus(other: `[`PPrism`](../-p-prism/index.html)`<A, B, C, D>): `[`POptional`](../-p-optional/index.html)`<S, T, C, D>`
`open operator fun plus(other: `[`Fold`](../-fold/index.html)`<A, C>): `[`Fold`](../-fold/index.html)`<S, C>`
`open operator fun <C, D> plus(other: `[`PTraversal`](../-p-traversal/index.html)`<A, B, C, D>): `[`PTraversal`](../-p-traversal/index.html)`<S, T, C, D>` | | [second](second.html) | Create a product of a type [C](second.html#C) and the [PLens](./index.html)`open fun second(): `[`PLens`](./index.html)`<Tuple2<C, S>, Tuple2<C, T>, Tuple2<C, A>, Tuple2<C, B>>` | | [set](set.html) | `abstract fun set(s: S, b: B): T` | | [split](split.html) | Pair two disjoint [PLens](./index.html)`open infix fun <S1, T1, A1, B1> split(other: `[`PLens`](./index.html)`<S1, T1, A1, B1>): `[`PLens`](./index.html)`<Tuple2<S, S1>, Tuple2<T, T1>, Tuple2<A, A1>, Tuple2<B, B1>>` |

Companion Object Functions

Extension Properties

Extension Functions