Merge pull request #529 from hsaputra/cleanup_right_arrowop_scala

Change the ⇒ character (maybe from scalariform) to => in Scala code for style consistency

Looks like there are some ⇒ Unicode character (maybe from scalariform) in Scala code.
This PR is to change it to => to get some consistency on the Scala code.

If we want to use ⇒ as default we could use sbt plugin scalariform to make sure all Scala code has ⇒ instead of =>

And remove unused imports found in TwitterInputDStream.scala while I was there =)

Author: Henry Saputra <hsaputra@apache.org>

== Merge branch commits ==

commit 29c1771d346dff901b0b778f764e6b4409900234
Author: Henry Saputra <hsaputra@apache.org>
Date:   Sat Feb 1 22:05:16 2014 -0800

    Change the ⇒ character (maybe from scalariform) to => in Scala code for style consistency.

examples/src/main/scala/org/apache/spark/streaming/examples/ActorWordCount.scala

@@ -88,7 +88,7 @@ extends Actor with Receiver {
   override def preStart = remotePublisher ! SubscribeReceiver(context.self)
 
   def receive = {
-    case msg ⇒ pushBlock(msg.asInstanceOf[T])
+    case msg => pushBlock(msg.asInstanceOf[T])
   }
 
   override def postStop() = remotePublisher ! UnsubscribeReceiver(context.self)

external/twitter/src/main/scala/org/apache/spark/streaming/twitter/TwitterInputDStream.scala

@@ -17,14 +17,11 @@
 
 package org.apache.spark.streaming.twitter
 
-import java.util.prefs.Preferences
 import twitter4j._
 import twitter4j.auth.Authorization
 import twitter4j.conf.ConfigurationBuilder
-import twitter4j.conf.PropertyConfiguration
 import twitter4j.auth.OAuthAuthorization
-import twitter4j.auth.AccessToken
-import org.apache.spark._
+
 import org.apache.spark.streaming._
 import org.apache.spark.streaming.dstream._
 import org.apache.spark.storage.StorageLevel

external/zeromq/src/main/scala/org/apache/spark/streaming/zeromq/ZeroMQReceiver.scala

@@ -31,7 +31,7 @@ import org.apache.spark.streaming.receivers._
  */
 private[streaming] class ZeroMQReceiver[T: ClassTag](publisherUrl: String,
   subscribe: Subscribe,
-  bytesToObjects: Seq[ByteString] ⇒ Iterator[T])
+  bytesToObjects: Seq[ByteString] => Iterator[T])
   extends Actor with Receiver with Logging {
 
   override def preStart() = ZeroMQExtension(context.system).newSocket(SocketType.Sub, Listener(self),
@@ -39,16 +39,16 @@ private[streaming] class ZeroMQReceiver[T: ClassTag](publisherUrl: String,
 
   def receive: Receive = {
 
-    case Connecting ⇒ logInfo("connecting ...")
+    case Connecting => logInfo("connecting ...")
 
-    case m: ZMQMessage ⇒
+    case m: ZMQMessage =>
       logDebug("Received message for:" + m.frame(0))
 
       //We ignore first frame for processing as it is the topic
       val bytes = m.frames.tail
       pushBlock(bytesToObjects(bytes))
 
-    case Closed ⇒ logInfo("received closed ")
+    case Closed => logInfo("received closed ")
 
   }
 }

external/zeromq/src/main/scala/org/apache/spark/streaming/zeromq/ZeroMQUtils.scala

@@ -46,7 +46,7 @@ object ZeroMQUtils {
       ssc: StreamingContext,
       publisherUrl: String,
       subscribe: Subscribe,
-      bytesToObjects: Seq[ByteString] ⇒ Iterator[T],
+      bytesToObjects: Seq[ByteString] => Iterator[T],
       storageLevel: StorageLevel = StorageLevel.MEMORY_AND_DISK_SER_2,
       supervisorStrategy: SupervisorStrategy = ReceiverSupervisorStrategy.defaultStrategy
     ): DStream[T] = {

streaming/src/main/scala/org/apache/spark/streaming/receivers/ActorReceiver.scala

@@ -37,8 +37,8 @@ object ReceiverSupervisorStrategy {
 
   val defaultStrategy = OneForOneStrategy(maxNrOfRetries = 10, withinTimeRange =
     15 millis) {
-    case _: RuntimeException ⇒ Restart
-    case _: Exception ⇒ Escalate
+    case _: RuntimeException => Restart
+    case _: Exception => Escalate
   }
 }
 
@@ -66,7 +66,7 @@ object ReceiverSupervisorStrategy {
  */
 trait Receiver {
 
-  self: Actor ⇒ // to ensure that this can be added to Actor classes only
+  self: Actor => // to ensure that this can be added to Actor classes only
 
   /**
    * Push an iterator received data into Spark Streaming for processing
@@ -139,25 +139,25 @@ private[streaming] class ActorReceiver[T: ClassTag](
 
     def receive = {
 
-      case Data(iter: Iterator[_]) ⇒ pushBlock(iter.asInstanceOf[Iterator[T]])
+      case Data(iter: Iterator[_]) => pushBlock(iter.asInstanceOf[Iterator[T]])
 
-      case Data(msg) ⇒
+      case Data(msg) =>
         blocksGenerator += msg.asInstanceOf[T]
         n.incrementAndGet
 
-      case props: Props ⇒
+      case props: Props =>
         val worker = context.actorOf(props)
         logInfo("Started receiver worker at:" + worker.path)
         sender ! worker
 
-      case (props: Props, name: String) ⇒
+      case (props: Props, name: String) =>
         val worker = context.actorOf(props, name)
         logInfo("Started receiver worker at:" + worker.path)
         sender ! worker
 
       case _: PossiblyHarmful => hiccups.incrementAndGet()
 
-      case _: Statistics ⇒
+      case _: Statistics =>
         val workers = context.children
         sender ! Statistics(n.get, workers.size, hiccups.get, workers.mkString("\n"))