react Scala

$ more Main.scala
import scala.actors.Actor._
import scala.actors._

package com.ykishi.scala {

object Main extends Actor {

case class MetaInfo ( key: Int, value: String )

def act() {
react {
case s: String =>
reply ( "Thanks! " + s )
act()
case m: MetaInfo =>
println ( "*** received: " + m.key + "," + m.value )
reply ( "successfully completed!" )
act()
case -1 => {
reply ( "BYE!" )
exit()
}

}
}

def main ( args: Array[String] ) {

var a = Main.start()

println ( a !? "HELLO!" )

println ( a !? MetaInfo ( 1123, "KISHI Yasuhiro" ) )

val retval = a !? -1
println ( "Actor's reply: " + retval )

}

}

}

$ ./test1.sh
Thanks! HELLO!
*** received: 1123,KISHI Yasuhiro
successfully completed!
Actor's reply: BYE!