arrow-fx-coroutines / arrow.fx.coroutines / Promise / complete

complete

abstract suspend fun complete(a: A): Either<AlreadyFulfilled, Unit>

Completes, or fulfills, the promise with the specified value A. Returns Promise.AlreadyFulfilled in Either.Left if the promise is already fulfilled.

import arrow.fx.coroutines.*

suspend fun main(): Unit {
  //sampleStart
  val p = Promise<Int>()
  p.complete(1)
  val r1 = p.get()
  val failed = p.complete(2)
  val r2 = p.get()
  //sampleEnd
  println("r1: $r1, failed: $failed, r2: $r2")
}