arrow-optics/arrow.optics.dsl/at

at

fun <T, S, I, A> Lens<T, S>.at(at: At<S, I, A>, i: I): Lens<T, A>

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

Receiver

Lens with a focus in S

Return

Lens with a focus in A at given index I.

Parameters

at

At instance to provide a Lens to zoom into S at I

i

index I to zoom into S and find focus A

fun <T, S, I, A> Optional<T, S>.at(at: At<S, I, A>, i: I): Optional<T, A>

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

Receiver

Optional or Prism with a focus in S

Return

Optional with a focus in A at given index I.

Parameters

at

At instance to provide a Lens to zoom into S at I

i

index I to zoom into S and find focus A

fun <T, S, I, A> Traversal<T, S>.at(at: At<S, I, A>, i: I): Traversal<T, A>

DSL to compose At 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

at

At instance to provide a Lens to zoom into S at I

i

index I to zoom into S and find focus A

fun <T, K, V> Lens<T, Map<K, V>>.at(key: K): Lens<T, Option<V>>
fun <T, K, V> Optional<T, Map<K, V>>.at(key: K): Optional<T, Option<V>>
fun <T, K, V> Traversal<T, Map<K, V>>.at(key: K): Traversal<T, Option<V>>
@JvmName(name = "atSet")
fun <T, A> Lens<T, Set<A>>.at(value: A): Lens<T, Boolean>
@JvmName(name = "atSet")
fun <T, A> Optional<T, Set<A>>.at(value: A): Optional<T, Boolean>
@JvmName(name = "atSet")
fun <T, A> Traversal<T, Set<A>>.at(value: A): Traversal<T, Boolean>