Scala actor消息定义 [英] scala actor message definition

问题描述

我需要为要在scala actor上检索的消息定义类吗?

Do i need to define class for message i want to retrieve on a scala actor?

我试图把它弄醒 我在哪里错了

i trying to get this up where am i wrong

  def act() {  
    loop {  
      react {  
        case Meet => foundMeet = true ;   goHome  
        case Feromone(qty) if (foundMeet == true) => sender ! Feromone(qty+1); goHome  
   }}}

推荐答案

您可以将其视为正常的模式匹配，如下所示.

You can think it as a normal pattern matching just like the following.

match (expr)
{
   case a =>
   case b =>
}

所以，是的，您应该先定义它，对不带参数的Message使用object，对具有参数的case类使用. (正如西尔维奥·比尔曼(Silvio Bierman)所指出的，实际上，您可以使用任何可以进行模式匹配的东西，因此我对该示例进行了一些修改)

So, yes, you should define it first, use object for Message without parameters and case class for those has parameters. (As Silvio Bierman pointed out, in fact, you could use anything that could be pattern-matched, so I modified this example a little)

以下是示例代码.

import scala.actors.Actor._
import scala.actors.Actor

object Meet
case class Feromone (qty: Int)

class Test extends Actor
{
    def act ()
    {
        loop {
            react {
                case Meet => println ("I got message Meet....")
                case Feromone (qty) => println ("I got message Feromone, qty is " + qty)
                case s: String => println ("I got a string..." + s)
                case i: Int => println ("I got an Int..." + i)
            }
        }
    }
}

val actor = new Test
actor.start

actor ! Meet
actor ! Feromone (10)
actor ! Feromone (20)
actor ! Meet
actor ! 123
actor ! "I'm a string"

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