Scala SIP Coroutines - A simple example of blocking launcher.

BlockingLauncher.scala

class Blocking extends Unwrapped[A], StarterLib:
  val ec: ExecutionContextExecutorService =
    ExecutionContext.fromExecutorService(Executors.newSingleThreadExecutor())
  sys.addShutdownHook(this.close)
  def close: Unit = ec.close()
  def apply(block: Continuation[A] ?=> A): A =
    val boundary = new Boundary[A] { var result = null }
    val latch = new CountDownLatch(1)
    val baseContinuation = BuildContinuation(
      ec,
      res => {
        boundary.result = res
        latch.countDown()
      })
    new Starter[A] {
      override def invoke(completion: Continuation[A]): A | Any | Null =
        given Continuation[A] = completion
        block
    }.start(baseContinuation)
    latch.await()
    boundary.result match
      case Left(e) => throw e
      case Right(Right(v)) => v.asInstanceOf[A]
      case Right(v) => v.asInstanceOf[A]