Question

您好我正在使用以下示例并希望返回最终结果，即所有演员完成各自的工作时的列表，即当尺寸== 0时。我想在主要的通话类即Factorial中收到列表的最终结果。我怎样才能做到这一点？任何建议都将受到高度赞赏。

{
import scala.annotation.tailrec

import akka.actor.{Actor, ActorLogging, ActorSystem, Props}

object Factorial extends App {
  val factorials = List(20, 18, 32, 28, 22, 42, 55, 48)

  val system = ActorSystem("factorial")

  val collector = system.actorOf(Props(new FactorialCollector(factorials)), "collector")
}

class FactorialCollector(factorials: List[Int]) extends Actor with ActorLogging {
  var list: List[BigInt] = Nil
  var size = factorials.size

  for (num <- factorials) {
    context.actorOf(Props(new FactorialCalculator)) ! num
  }

  def receive = {
    case (num: Int, fac: BigInt) => {
      log.info(s"factorial for $num is $fac")

      list = num :: list
      size -= 1

      if (size == 0) {
        context.system.shutdown()
      }
    }
  }
}

class FactorialCalculator extends Actor {
  def receive = {
    case num: Int => sender ! (num, factor(num))
  }

  private def factor(num: Int) = factorTail(num, 1)

  @tailrec private def factorTail(num: Int, acc: BigInt): BigInt = {
    (num, acc) match {
      case (0, a) => a
      case (n, a) => factorTail(n - 1, n * a)
    }
  }
}}

如何从scala actor模型

0 个答案: