From c3f7aac8f3342c5b47e9dac6988b422ff7cbe289 Mon Sep 17 00:00:00 2001
From: Roland <rk@rkuhn.info>
Date: Mon, 7 May 2012 18:21:26 +0200
Subject: [PATCH] make transform DSL nicer, see #1966

---
 .../src/test/scala/akka/actor/FSMActorSpec.scala     |  2 +-
 akka-actor/src/main/scala/akka/actor/FSM.scala       | 12 ++++++++----
 .../scala/code/akka/docs/actor/FSMDocSpec.scala      |  4 ++--
 akka-docs/scala/fsm.rst                              |  2 --
 4 files changed, 11 insertions(+), 9 deletions(-)

diff --git a/akka-actor-tests/src/test/scala/akka/actor/FSMActorSpec.scala b/akka-actor-tests/src/test/scala/akka/actor/FSMActorSpec.scala
index a84e23799a..ef49cbc18d 100644
--- a/akka-actor-tests/src/test/scala/akka/actor/FSMActorSpec.scala
+++ b/akka-actor-tests/src/test/scala/akka/actor/FSMActorSpec.scala
@@ -268,7 +268,7 @@ class FSMActorSpec extends AkkaSpec(Map("akka.actor.debug.fsm" -> true)) with Im
         startWith(0, 0)
         when(0)(transform {
           case Event("go", _) ⇒ stay
-        } {
+        } using {
           case x ⇒ goto(1)
         })
         when(1) {
diff --git a/akka-actor/src/main/scala/akka/actor/FSM.scala b/akka-actor/src/main/scala/akka/actor/FSM.scala
index fbe6622c68..db89f58946 100644
--- a/akka-actor/src/main/scala/akka/actor/FSM.scala
+++ b/akka-actor/src/main/scala/akka/actor/FSM.scala
@@ -217,8 +217,8 @@ trait FSM[S, D] extends Listeners with ActorLogging {
    * @param timeout state timeout for the initial state, overriding the default timeout for that state
    */
   protected final def startWith(stateName: S,
-                                stateData: D,
-                                timeout: Timeout = None): Unit =
+    stateData: D,
+    timeout: Timeout = None): Unit =
     currentState = FSM.State(stateName, stateData, timeout)
 
   /**
@@ -253,8 +253,12 @@ trait FSM[S, D] extends Listeners with ActorLogging {
    */
   protected final def stop(reason: Reason, stateData: D): State = stay using stateData withStopReason (reason)
 
-  protected final def transform(func: StateFunction)(andThen: PartialFunction[State, State]): StateFunction =
-    func andThen (andThen orElse { case x ⇒ x })
+  protected final class TransformHelper(func: StateFunction) {
+    def using(andThen: PartialFunction[State, State]): StateFunction =
+      func andThen (andThen orElse { case x ⇒ x })
+  }
+
+  protected final def transform(func: StateFunction): TransformHelper = new TransformHelper(func)
 
   /**
    * Schedule named timer to deliver message after given delay, possibly repeating.
diff --git a/akka-docs/scala/code/akka/docs/actor/FSMDocSpec.scala b/akka-docs/scala/code/akka/docs/actor/FSMDocSpec.scala
index 3e17c38cc4..158f8979a0 100644
--- a/akka-docs/scala/code/akka/docs/actor/FSMDocSpec.scala
+++ b/akka-docs/scala/code/akka/docs/actor/FSMDocSpec.scala
@@ -128,7 +128,7 @@ class FSMDocSpec extends AkkaSpec {
         when(SomeState)(transform {
           case Event(bytes: Array[Byte], read) ⇒ stay using (read + bytes.length)
           case Event(bytes: List[Byte], read)  ⇒ stay using (read + bytes.size)
-        } {
+        } using {
           case s @ FSM.State(state, read, timeout, stopReason, replies) if read > 1000 ⇒
             goto(Processing)
         })
@@ -143,7 +143,7 @@ class FSMDocSpec extends AkkaSpec {
         when(SomeState)(transform {
           case Event(bytes: Array[Byte], read) ⇒ stay using (read + bytes.length)
           case Event(bytes: List[Byte], read)  ⇒ stay using (read + bytes.size)
-        }(processingTrigger))
+        } using processingTrigger)
         //#alt-transform-syntax
 
         //#termination-syntax
diff --git a/akka-docs/scala/fsm.rst b/akka-docs/scala/fsm.rst
index 3b60058701..807cd7567c 100644
--- a/akka-docs/scala/fsm.rst
+++ b/akka-docs/scala/fsm.rst
@@ -329,8 +329,6 @@ be used several times, e.g. when applying the same transformation to several
 .. includecode:: code/akka/docs/actor/FSMDocSpec.scala
    :include: alt-transform-syntax
 
-The parentheses are required by Scala’s syntax rules.
-
 Timers
 ------