iterator

Builds an Iterator lazily yielding values one by one.

fun <T> iterator(block: suspend SequenceScope<T>.() -> Unit): Iterator<T>(source)

import kotlin.sequences.iterator

fun main() {
    val numbers = iterator<Int> {
        for (i in 1..5) {
            yield(i)          // produce the next value lazily
        }
    }

    numbers.forEach { println(it) }   // prints 1 2 3 4 5
}

Source