使用案例类和参与者键入不匹配（字符串） [英] Type mismatch (String) using case class and actor

问题描述

当我尝试引用代码时出现某些格式问题，因此，图片如下：（

Some format issue when I'm trying to quote the code, so here is the picture :(

此处的图片描述

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

case class Number(n: Int)
case class String(s: String)

class DoublingActor extends Actor {
  def receive: Receive = {
    case Number(n) => println(s"Result of doubling $n: ${n*2}")
    case String(s) => println(s"Result of doubling $s: ${s}${s}")
  }
}

object Double extends App {
  val system = ActorSystem("DoublerSystme")
  val doubler = system.actorOf(Props[DoublingActor], "doubler")

  doubler ! Number(5)
  doubler ! String("test")
}

问题是，演员可以很好地处理数字，但是如何添加返回两次字符串的匹配函数？

The thing is, the actor works fine with number, but how can I add the matching function that returns the string twice?

推荐答案

您看到了什么行为？由于您的问题被包装在图像中，因此无法确定是否进行测试，但是我希望您收到描述性消息 object的编译错误，字符串不是case类，也不是它有一个unapply / unapplySeq成员。

What behavior are you seeing? Due to your issue being wrapped in an image, I can't test for sure, but I'd expect that you are getting a compile error with the descriptive message object String is not a case class, nor does it have an unapply/unapplySeq member.

因为它没有 unapply 成员，您需要将语句修改为

Because it doesn't have the unapply member, you'll need to modify your statement to

case s: String => println(s"Result of doubling $s: ${s}:${s}")

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