Scala example source code file (message.scala)

This example Scala source code file (message.scala) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Scala tags/keywords

actor, array, array, incrementor, int, int, message, message, pid, pid

The Scala message.scala source code

/* The Computer Language Shootout
   http://shootout.alioth.debian.org/
   contributed by Isaac Gouy
*/


import scala.concurrent._ 

object message {
   def main(args: Array[String]) = {
      val n = Integer.parseInt(args(0))
      val nActors = 500
      val finalSum = n * nActors

      case class Message(value: Int)

      class Incrementor(next: Pid) extends Actor {
         var sum = 0

         override def run() = {
            while (true) {
               receive { 
                  case Message(value) => 
                     val j = value + 1 
                     if (null != next){ 
                        next ! Message(j) 
                     } else { 
                        sum = sum + j
                        if (sum >= finalSum){ 
                           Console.println(sum); 
                           System.exit(0) // exit without cleaning up
                        }
                     } 
               }
            }
         }

         def pid() = { this.start; this.self }
      }

      def actorChain(i: Int, a: Pid): Pid = 
         if (i > 0) actorChain(i-1, new Incrementor(a).pid ) else a

      val firstActor = actorChain(nActors, null)
      var i = n; while (i > 0){ firstActor ! Message(0); i = i-1 }
   }
}