Addded method 'context' to UntypedActor. Changed the Pi calculation to use tail-recursive function

akka-actor/src/main/scala/akka/actor/UntypedActor.scala

@@ -4,14 +4,8 @@
 
 package akka.actor
 
-import akka.dispatch._
-import akka.config.Supervision._
 import akka.japi.{Creator, Procedure}
 
-import java.net.InetSocketAddress
-
-import scala.reflect.BeanProperty
-
 /**
  * Subclass this abstract class to create a MDB-style untyped actor.
  * <p/>
@@ -63,6 +57,7 @@ import scala.reflect.BeanProperty
 abstract class UntypedActor extends Actor {
 
   def getContext(): ActorRef = self
+  def context(): ActorRef    = self
 
   final protected def receive = {
     case msg => onReceive(msg)
@@ -88,4 +83,4 @@ abstract class UntypedActor extends Actor {
  *
  * @author <a href="http://jonasboner.com">Jonas Bon&#233;r</a>
  */
-trait UntypedActorFactory extends Creator[Actor]
+trait UntypedActorFactory extends Creator[Actor]

akka-tutorials/akka-tutorial-first/src/main/scala/Pi.scala

@@ -13,6 +13,8 @@ import akka.dispatch.Dispatchers
 import System.{currentTimeMillis => now}
 import java.util.concurrent.CountDownLatch
 
+import scala.annotation.tailrec
+
 /**
  * First part in Akka tutorial.
  * <p/>
@@ -57,6 +59,7 @@ object Pi extends App {
   class Worker() extends Actor {
     // define the work
 
+/*
     // FIXME tail-recursive fun instead
     val calculatePiFor = (arg: Int, nrOfElements: Int) => {
       val range = (arg * nrOfElements) to ((arg + 1) * nrOfElements - 1)
@@ -66,6 +69,15 @@ object Pi extends App {
       // Use this for more functional style but is twice as slow
       // range.foldLeft(0.0D)( (acc, i) =>  acc + 4 * math.pow(-1, i) / (2 * i + 1) )
     }
+*/
+    def calculatePiFor(arg: Int, nrOfElements: Int): Double = {
+      val end = (arg + 1) * nrOfElements - 1
+      @tailrec def doCalculatePiFor(cursor: Int, acc: Double): Double = {
+        if (end == cursor) acc
+        else doCalculatePiFor(cursor + 1, acc + (4 * math.pow(-1, cursor) / (2 * cursor + 1)))
+      }
+      doCalculatePiFor(arg * nrOfElements, 0.0D)
+    }
 
     def receive = {
       case Work(arg, nrOfElements) =>