Scala学习之Actor

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

case class Point(val x: Double, val y: Double) { 
    //override def toString() = "Point(" + x + "," + y + ")"  //using case keywords ,we no longer need to imp toString
   // def drawCurry(str:String)= println(str);
   //  def drawCurry(str:String)(str2:String) ={drawCurry(str); println("    "+str2); }
  } 
  abstract class Shape() { 
    def draw(): Unit 
  } 
  case class Dot(val on:Point) extends Shape
{
     def draw()=println("dot draw:    "+this)
}

// must be override "val" and not "var" , var parameter can not been overrided
class MyDot(override val on:Point) extends Dot(on)
{
}

log(new MyDot(Point(2,3)).toString)

case class Circle(val center: Point, val radius: Double)  
  extends Shape { 
    def draw() = println("Circle.draw: " + this) 
  //  override def toString() =  
  //     "Circle(" + center + "," + radius + ")" 
  } 
  case class Rectangle(val lowerLeft: Point, val height: Double, val width: Double) 
        extends Shape { 
    def draw() = println("Rectangle.draw: " + this) 
   // override def toString() = 
    //  "Rectangle(" + lowerLeft + "," + height + "," + width + ")" 
  } 
  case class Triangle(val point1: Point, val point2: Point, val point3: Point) 
        extends Shape { 
    def draw() = println("Triangle.draw: " + this) 

        // case create this method
  //  override def toString() = 
   //   "Triangle(" + point1 + "," + point2 + "," + point3 + ")" 
   
  } 


object ShapeDrawingActor extends Actor { 
    def act() { 
      loop { 
        receive { 
          case s: Shape => s.draw() 
          case "exit"   => println("exiting..."); exit 
      case str:String => println(str.toUpperCase())
          case x: Any   => println("Error: Unknown message! " + x) 
        } 
      } 
    } 
  } 




ShapeDrawingActor.start() 
  ShapeDrawingActor ! "Hello"
ShapeDrawingActor ! new Circle(new Point(0.0,0.0), 1.0) 
ShapeDrawingActor ! new Rectangle(new Point(0.0,0.0), 2, 5) 
ShapeDrawingActor ! new Triangle(new Point(0.0,0.0), 
                                 new Point(1.0,0.0), 
                                 new Point(0.0,1.0)) 
ShapeDrawingActor ! 3.14159 

ShapeDrawingActor ! "exit"