arrow-fx-coroutines / arrow.fx.coroutines.stream / lastOrNull

lastOrNull

suspend fun <O> Stream<O>.lastOrNull(): O?

Runs all the effects of this Stream, and returns null if the stream emitted no values and returning the last value emitted if values were emitted.

import arrow.fx.coroutines.stream.*

//sampleStart
suspend fun main(): Unit =
  Stream(1, 2, 3)
    .lastOrNull()
    .let(::println) // 3
//sampleEnd

This a terminal operator, meaning this functions suspends until the Stream finishes. If any errors are raised while streaming, it’s thrown from this suspend scope.