我有一个名为Gate的Akka Actor，它用Open或Closed的响应消息来回答Status消息：

"A stateless gate" must {
    "be open" in {
      val parent = TestProbe()
      val gate = parent.childActorOf(
        TestStatelessGate.props(7)
      )
      gate ! 7
      gate ! Gate.Status
      parent.expectMsg(Gate.Open)
    }

我想做的是构造一个逻辑AND门，它查询一个门列表，如果它们都是打开的，则返回Open：

"A logical AND gate" must {
    "be open when all children are open" in {
      val parent = TestProbe()
      val parent2 = TestProbe()
      val gate_1 = parent.childActorOf(
        TestStatelessGate.props(7)
      )
      val gate_2 = parent.childActorOf(
        TestStatelessGate.props(5)
      )
      val gate_list = List(gate_1, gate_2)
      val and_gate = parent2.childActorOf(
        LogicalAndGate.props(gate_list)
      )
      gate_1 ! 7
      gate_2 ! 5
      and_gate ! Gate.Status
      parent2.expectMsg(Gate.Open)

Scala文档中有一些关于使用for表达式和pipe的内容。该文档的相关部分是：

final case class Result(x: Int, s: String, d: Double)
case object Request

implicit val timeout = Timeout(5 seconds) // needed for `?` below

val f: Future[Result] =
  for {
    x <- ask(actorA, Request).mapTo[Int] // call pattern directly
    s <- actorB.ask(Request).mapTo[String] // call by implicit conversion
    d <- (actorC ? Request).mapTo[Double] // call by symbolic name
  } yield Result(x, s, d)

f.pipeTo(actorD

我在尝试使用ActorRef列表执行类似的操作时遇到了问题（下面的代码中为gate_list）：

override def receive: Receive = {
    case Status => {
      val futures: Seq[Future[Any]] =
        for (g <- gate_list)
          yield ask(g, Status)
      val all_open: Future[Boolean] = Future {
        !futures.contains(Closed)
        }
      pipe(all_open) to parent
    }
  }

当然，这是行不通的，因为futures.contains(Closed)比较的是两种不同类型的东西，一个Future[Any]和我的case对象。