Added actors library.

1 files changed, 66 insertions, 0 deletions

diff --git a/docs/examples/actors/customer.scala b/docs/examples/actors/customer.scala
new file mode 100644
index 0000000000..64453aee16
--- /dev/null
+++ b/docs/examples/actors/customer.scala
@@ -0,0 +1,66 @@
+/**
+ @author Philipp Haller <philipp.haller@epfl.ch>
+
+ This shows "customer passing" for implementing
+ recursive algorithms using actors.
+ */
+
+import scala.actors._;
+import scala.actors.single._;
+
+abstract class FactorialMessage;
+case class Factorial(n: int, resTo: Actor) extends FactorialMessage;
+case class Value(n: int) extends FactorialMessage;
+
+class FactorialProcess extends Actor {
+  override def run: unit = {
+    receive {
+      case Factorial(n, resTo) =>
+        if (n == 0) {
+          Debug.info("Sending Value(1) to " + resTo)
+          resTo send Value(1)
+        }
+        else {
+          // spawn process that multiplies
+          /*val m = spawnReceive({
+            case Value(value) => resTo send Value(n * value)
+          });*/
+
+          val m = new MultiplyActor(n, resTo)
+          m.start
+          Debug.info("Sending Factorial(" + (n-1) + ", " + m + ") to " + this)
+          this send Factorial(n-1, m)
+        }
+        run
+    }
+  }
+}
+
+class MultiplyActor(factor: int, resTo: Actor) extends Actor {
+  override def run: unit =
+    receive {
+      case Value(value) =>
+        Debug.info("Sending Value(" + factor * value + ") to " + resTo)
+        resTo send Value(factor * value)
+        Debug.info("Done sending.")
+    }
+}
+
+object CustomerPassing {
+  def main(args: Array[String]): unit = {
+    val fac = new FactorialProcess
+    fac.start
+
+    val c = new Actor {
+      override def run: unit = {
+        fac send Factorial(3, this)
+
+        receive {
+          case Value(value) =>
+            System.out.println("Result: " + value)
+        }
+      }
+    }
+    c.start
+  }
+}