Changed Iterator to take immutable.Seq instead of mutable.Seq. Also changed Pi tutorial to use Vector instead of Array

akka-actor/src/main/scala/akka/routing/Iterators.scala

@@ -6,6 +6,7 @@ package akka.routing
 
 import akka.actor.ActorRef
 import scala.collection.JavaConversions._
+import scala.collection.immutable.Seq
 
 /**
  * An Iterator that is either always empty or yields an infinite number of Ts.
@@ -18,7 +19,7 @@ trait InfiniteIterator[T] extends Iterator[T] {
  * CyclicIterator is a round-robin style InfiniteIterator that cycles the supplied List.
  */
 case class CyclicIterator[T](val items: Seq[T]) extends InfiniteIterator[T] {
-  def this(items: java.util.List[T]) = this(items.toSeq)
+  def this(items: java.util.List[T]) = this(items.toList)
 
   @volatile private[this] var current: Seq[T] = items
 
@@ -38,7 +39,7 @@ case class CyclicIterator[T](val items: Seq[T]) extends InfiniteIterator[T] {
  * useful for work-stealing.
  */
 case class SmallestMailboxFirstIterator(val items : Seq[ActorRef]) extends InfiniteIterator[ActorRef] {
-  def this(items: java.util.List[ActorRef]) = this(items.toSeq)
+  def this(items: java.util.List[ActorRef]) = this(items.toList)
   def hasNext = items != Nil
 
   def next = items.reduceLeft((a1, a2) => if (a1.mailboxSize < a2.mailboxSize) a1 else a2)

akka-tutorials/akka-tutorial-pi-sbt/src/main/scala/Pi.scala

@@ -63,8 +63,8 @@ object Pi  {
 
     // create the workers
     val workers = {
-      val ws = new Array[ActorRef](nrOfWorkers)
-      for (i <- 0 until nrOfWorkers) ws(i) = actorOf[Worker].start
+      var ws = Vector[ActorRef]()
+      for (i <- 0 until nrOfWorkers) ws = ws :+ actorOf[Worker].start
       ws
     }