如何將PartialFunction與另一個函數結合並返回PartialFunction？

Question

我有以下類：

class MessageProcessorActor(private val destination : ActorRef) extends Actor{ 
    override def receive: Receive = { 
    case _ => 
    destination ! { 
     case MyActor.TracableMessage(msg) => MyActor.TracableMessage("Processed + " + msg) 
     case MyActor.Message(msg) => MyActor.Message("Processed + " + msg) 
     case _ => "Processed + " + _ 
    }(_) 
    } 
} 

object MyActor{ 
    case class TracableMessage(private val msg: String) extends Message(msg) 
    case class Message(private val msg: String) 
} 

凡爲

type Receive = PartialFunction[Any, Unit] 

在這裏，我試圖避免宣佈val拿着PartialFunction[Any, Any]並調用它這樣Recieve定義。但編譯器拒絕此代碼。它打印：

Error:(12, 6) ';' expected but '(' found. 
    }(_) 
    ^

是否有一個簡短的方法來做這樣的事情？

Answer 1

你爲什麼試圖這樣寫？跟着怎麼了

class MessageProcessorActor(private val destination : ActorRef) extends Actor{ 
    override def receive: Receive = { 
    case MyActor.TracableMessage(msg) => { 
     destination ! MyActor.TracableMessage("Processed + " + msg) 
    } 
    case MyActor.Message(msg) => { 
     destination ! MyActor.Message("Processed + " + msg) 
    } 
    case _ => { 
     destination ! "Processed + " + _ 
    } 
    } 
} 

object MyActor{ 
    case class TracableMessage(private val msg: String) extends Message(msg) 
    case class Message(private val msg: String) 
}