asSequence

Returns this sequence as a Sequence.

inline fun <T> Sequence<T>.asSequence(): Sequence<T>(source)

val numbers = listOf(1, 2, 3, 4, 5)

val doubledEven = numbers.asSequence()
    .filter { it % 2 == 0 }
    .map { it * 2 }
    .toList()

println(doubledEven)  // prints: [4, 8]

Source