add FSMDocSpec and improve FSM API

- don’t require Option[Duration] and its implicit conversion
- provider “->” extractor inside the FSM trait

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

@@ -49,21 +49,6 @@ object FSM {
     }
   }
 
-  /*
-   * This extractor is just convenience for matching a (S, S) pair, including a
-   * reminder what the new state is.
-   */
-  object -> {
-    def unapply[S](in: (S, S)) = Some(in)
-  }
-
-  /*
-  * With these implicits in scope, you can write "5 seconds" anywhere a
-  * Duration or Option[Duration] is expected. This is conveniently true
-  * for derived classes.
-  */
-  implicit def d2od(d: Duration): Option[Duration] = Some(d)
-
   case class LogEntry[S, D](stateName: S, stateData: D, event: Any)
 
   case class State[S, D](stateName: S, stateData: D, timeout: Option[Duration] = None, stopReason: Option[Reason] = None, replies: List[Any] = Nil) {
@@ -208,7 +193,12 @@ trait FSM[S, D] extends Listeners {
    * @param stateTimeout default state timeout for this state
    * @param stateFunction partial function describing response to input
    */
-  protected final def when(stateName: S, stateTimeout: Timeout = None)(stateFunction: StateFunction) = {
+  protected final def when(stateName: S, stateTimeout: Duration = null)(stateFunction: StateFunction) = {
+    register(stateName, stateFunction, Option(stateTimeout))
+  }
+
+  @deprecated("use the more import-friendly variant taking a Duration", "2.0")
+  protected final def when(stateName: S, stateTimeout: Timeout)(stateFunction: StateFunction) = {
     register(stateName, stateFunction, stateTimeout)
   }
 
@@ -312,6 +302,14 @@ trait FSM[S, D] extends Listeners {
     stateTimeouts(state) = timeout
   }
 
+  /**
+   * This extractor is just convenience for matching a (S, S) pair, including a
+   * reminder what the new state is.
+   */
+  object -> {
+    def unapply[S](in: (S, S)) = Some(in)
+  }
+
   /**
    * Set handler which is called upon each state transition, i.e. not when
    * staying in the same state. This may use the pair extractor defined in the

akka-docs/scala/code/akka/docs/actor/FSMDocSpec.scala

@@ -0,0 +1,93 @@
+/**
+ * Copyright (C) 2009-2012 Typesafe Inc. <http://www.typesafe.com>
+ */
+package akka.docs.actor
+
+import akka.testkit.AkkaSpec
+
+class FSMDocSpec extends AkkaSpec {
+
+  "simple finite state machine" must {
+    //#simple-imports
+    import akka.actor.{ Actor, ActorRef, FSM, Props }
+    import akka.util.duration._
+    //#simple-imports
+    //#simple-events
+    // received events
+    case class SetTarget(ref: ActorRef)
+    case class Queue(obj: Any)
+    case object Flush
+
+    // sent events
+    case class Batch(obj: Seq[Any])
+    //#simple-events
+    //#simple-state
+    // states
+    trait State
+    case object Idle extends State
+    case object Active extends State
+
+    trait Data
+    case object Uninitialized extends Data
+    case class Todo(target: ActorRef, queue: Seq[Any]) extends Data
+    //#simple-state
+    //#simple-fsm
+    class Buncher extends Actor with FSM[State, Data] {
+
+      startWith(Idle, Uninitialized)
+
+      when(Idle) {
+        case Event(SetTarget(ref), Uninitialized) ⇒ stay using Todo(ref, Vector.empty)
+      }
+
+      //#simple-transition
+      onTransition {
+        case Active -> Idle ⇒
+          stateData match {
+            case Todo(ref, queue) ⇒ ref ! Batch(queue)
+          }
+      }
+      //#simple-transition
+
+      when(Active, stateTimeout = 1 second) {
+        case Event(Flush | FSM.StateTimeout, t: Todo) ⇒ goto(Idle) using t.copy(queue = Vector.empty)
+      }
+
+      //#simple-unhandled
+      whenUnhandled {
+        // common code for both states
+        case Event(Queue(obj), t @ Todo(_, v)) ⇒
+          goto(Active) using t.copy(queue = v :+ obj)
+
+        case Event(e, s) ⇒
+          log.warning("received unhandled request {} in state {}/{}", e, stateName, s)
+          stay
+      }
+      //#simple-unhandled
+
+      initialize
+    }
+    //#simple-fsm
+
+    "batch correctly" in {
+      val buncher = system.actorOf(Props(new Buncher))
+      buncher ! SetTarget(testActor)
+      buncher ! Queue(42)
+      buncher ! Queue(43)
+      expectMsg(Batch(Seq(42, 43)))
+      buncher ! Queue(44)
+      buncher ! Flush
+      buncher ! Queue(45)
+      expectMsg(Batch(Seq(44)))
+      expectMsg(Batch(Seq(45)))
+    }
+
+    "batch not if uninitialized" in {
+      val buncher = system.actorOf(Props(new Buncher))
+      buncher ! Queue(42)
+      expectNoMsg
+    }
+
+  }
+
+}

akka-testkit/src/main/scala/akka/testkit/TestFSMRef.scala

@@ -62,8 +62,8 @@ class TestFSMRef[S, D, T <: Actor](
    * corresponding transition initiated from within the FSM, including timeout
    * and stop handling.
    */
-  def setState(stateName: S = fsm.stateName, stateData: D = fsm.stateData, timeout: Option[Duration] = None, stopReason: Option[FSM.Reason] = None) {
-    fsm.applyState(FSM.State(stateName, stateData, timeout, stopReason))
+  def setState(stateName: S = fsm.stateName, stateData: D = fsm.stateData, timeout: Duration = null, stopReason: Option[FSM.Reason] = None) {
+    fsm.applyState(FSM.State(stateName, stateData, Option(timeout), stopReason))
   }
 
   /**