scala/ScalaBook/chapter-07/actors2.scala

import scala.actors._

class PrintProgressMark(val mark: Char, 
                        val delay :Int) extends Actor {
  private var mark_ = mark
  private var delay_ = delay
  private var i = 0
  private val max = 100
  def act: Unit = {
    while (i <= max) {
      print(mark_)
      i += 1
      Thread.sleep(delay_)
    }
  }
}

object actorsExample {
  def main(args: Array[String]) { 
    new PrintProgressMark('+', 40).start
    new PrintProgressMark('*', 100).start
  }
}