Scala 案例类在接收方法中不匹配(在 akka Actor 中)

Question

我有这样的事情:

class ProbeActor extends Actor {
  case class Probe(messageKey: String)
  def receiveProbe: Receive = {
    case Probe(probeKey) => println("Good probe: "+probeKey)
    case x => println("Bad probe: "+ x)
  }
  final override def receive = receiveProbe orElse receiveOther
  def receiveOther: Receive = {
    case _ => println("Other")
  }
}

我这样称呼它:

class Prober extends ProbeActor {
  val definite = ActorSystem("ProbeTest").actorOf(Props[ProbeActor], name = "probed")
  implicit val timeout = Timeout(5 second)
  val future = definite ? Probe("key")
}

我期待文本 "Good probe: key"应该打印，但我得到 "Bad probe: Probe(key)" .

备注 : 如果我把 Probe外面的案例类，然后它工作正常。

Answer 1

搜索更多后，我在 scala-lang.org 上找到了答案。 :

I think the underlying misconception is about the identity of nested class types.

In

class A { class B }

each new instance of class A x creates a new type x.B. And if you do the plain pattern match inside of A you are referring to the specific instance of the type B this.B.