arrow-optics/arrow.optics.typeclasses/Index/index

index

abstract fun index(i: I): Optional<S, A>

Get Optional focus A for a structure S at index i.

Return

Optional with a focus in A at given index I.

Parameters

i

index I to focus into S and find focus A

open fun <T> Optional<T, S>.index(i: I): Optional<T, A>

DSL to compose Index with an Optional for a structure S to focus in on A at given index I.

Receiver

Optional with a focus in S

Return

Optional with a focus in A at given index I.

Parameters

i

index I to focus into S and find focus A

open fun <T> Traversal<T, S>.index(i: I): Traversal<T, A>

DSL to compose Index with a Traversal for a structure S to focus in on A at given index I.

Receiver

Traversal with a focus in S

Return

Traversal with a focus in A at given index I.

Parameters

i

index I to focus into S and find focus A