I'm trying to compile the example from the official guide, the one with the ping pong. I've put the Ping and Pong classes in their own files, in the default package. However, the Ping class has compilation errors, saying it cannot find the Pong class, and vice versa. I also tried to clean the project so that a rebuild will happen, but I cannot make any progresses. I am using the final version of 2.8.1, from here.
What am I doing wrong?
The full source for pingpong.scala can be found in scala-2.8.1.final-sources.tgz
Location in tgz: scala-2.8.1.final-sources/docs/examples/actors/pingpong.scala
The example assumes all the classes are in the same file and can be compiled with
scalac pingpong.scala
But if you wanted to put them in separate files:
Ping.scala
import scala.actors.Actor
import scala.actors.Actor._
case object Ping
class Ping(count: Int, pong: Actor) extends Actor {
def act() {
var pingsLeft = count - 1
pong ! Ping
while (true) {
receive {
case Pong =>
if (pingsLeft % 1000 == 0)
Console.println("Ping: pong")
if (pingsLeft > 0) {
pong ! Ping
pingsLeft -= 1
} else {
Console.println("Ping: stop")
pong ! Stop
exit()
}
}
}
}
}
Pong.scala
import scala.actors.Actor
import scala.actors.Actor._
case object Pong
class Pong extends Actor {
def act() {
var pongCount = 0
while (true) {
receive {
case Ping =>
if (pongCount % 1000 == 0)
Console.println("Pong: ping "+pongCount)
sender ! Pong
pongCount = pongCount + 1
case Stop =>
Console.println("Pong: stop")
exit()
}
}
}
}
pingpong.scala
case object Stop
object pingpong extends Application {
val pong = new Pong
val ping = new Ping(100000, pong)
ping.start
pong.start
}
and then run scalac *.scala
