Add 'repeat' to RxScala

Author: zsxwing

language-adaptors/rxjava-scala/src/examples/scala/rx/lang/scala/examples/RxScalaDemo.scala

@@ -654,6 +654,16 @@ class RxScalaDemo extends JUnitSuite {
     assertFalse(o2.toBlockingObservable.single)
   }
 
+  @Test def repeatExample1(): Unit = {
+    val o : Observable[String] = List("alice", "bob", "carol").toObservable.repeat().take(6)
+    assertEquals(List("alice", "bob", "carol", "alice", "bob", "carol"), o.toBlockingObservable.toList)
+  }
+
+  @Test def repeatExample2(): Unit = {
+    val o : Observable[String] = List("alice", "bob", "carol").toObservable.repeat(2)
+    assertEquals(List("alice", "bob", "carol", "alice", "bob", "carol"), o.toBlockingObservable.toList)
+  }
+
   @Test def retryExample1(): Unit = {
     val o : Observable[String] = List("alice", "bob", "carol").toObservable
     assertEquals(List("alice", "bob", "carol"), o.retry.toBlockingObservable.toList)

language-adaptors/rxjava-scala/src/main/scala/rx/lang/scala/Observable.scala

@@ -2253,6 +2253,68 @@ trait Observable[+T]
     toScalaObservable[T](asJavaObservable.retry())
   }
 
+  /**
+   * Returns an Observable that repeats the sequence of items emitted by the source Observable indefinitely.
+   * <p>
+   * <img width="640" src="https://raw.github.com/wiki/Netflix/RxJava/images/rx-operators/repeat.o.png">
+   *
+   * @return an Observable that emits the items emitted by the source Observable repeatedly and in sequence
+   * @see <a href="https://github.com/Netflix/RxJava/wiki/Creating-Observables#wiki-repeat">RxJava Wiki: repeat()</a>
+   * @see <a href="http://msdn.microsoft.com/en-us/library/hh229428.aspx">MSDN: Observable.Repeat</a>
+   */
+  def repeat(): Observable[T] = {
+    toScalaObservable[T](asJavaObservable.repeat())
+  }
+
+  /**
+   * Returns an Observable that repeats the sequence of items emitted by the source Observable indefinitely,
+   * on a particular Scheduler.
+   * <p>
+   * <img width="640" src="https://raw.github.com/wiki/Netflix/RxJava/images/rx-operators/repeat.os.png">
+   *
+   * @param scheduler the Scheduler to emit the items on
+   * @return an Observable that emits the items emitted by the source Observable repeatedly and in sequence
+   * @see <a href="https://github.com/Netflix/RxJava/wiki/Creating-Observables#wiki-repeat">RxJava Wiki: repeat()</a>
+   * @see <a href="http://msdn.microsoft.com/en-us/library/hh229428.aspx">MSDN: Observable.Repeat</a>
+   */
+  def repeat(scheduler: Scheduler): Observable[T] = {
+    toScalaObservable[T](asJavaObservable.repeat(scheduler))
+  }
+
+  /**
+   * Returns an Observable that repeats the sequence of items emitted by the source Observable at most `count` times.
+   * <p>
+   * <img width="640" src="https://raw.github.com/wiki/Netflix/RxJava/images/rx-operators/repeat.on.png">
+   *
+   * @param count the number of times the source Observable items are repeated,
+   *              a count of 0 will yield an empty sequence
+   * @return an Observable that repeats the sequence of items emitted by the source Observable at most `count` times
+   * @throws IllegalArgumentException if `count` is less than zero
+   * @see <a href="https://github.com/Netflix/RxJava/wiki/Creating-Observables#wiki-repeat">RxJava Wiki: repeat()</a>
+   * @see <a href="http://msdn.microsoft.com/en-us/library/hh229428.aspx">MSDN: Observable.Repeat</a>
+   */
+  def repeat(count: Long): Observable[T] = {
+    toScalaObservable[T](asJavaObservable.repeat(count))
+  }
+
+  /**
+   * Returns an Observable that repeats the sequence of items emitted by the source Observable
+   * at most `count` times, on a particular Scheduler.
+   * <p>
+   * <img width="640" src="https://raw.github.com/wiki/Netflix/RxJava/images/rx-operators/repeat.ons.png">
+   *
+   * @param count the number of times the source Observable items are repeated,
+   *              a count of 0 will yield an empty sequence
+   * @param scheduler the `Scheduler` to emit the items on
+   * @return an Observable that repeats the sequence of items emitted by the source Observable at most `count` times
+   *         on a particular Scheduler
+   * @see <a href="https://github.com/Netflix/RxJava/wiki/Creating-Observables#wiki-repeat">RxJava Wiki: repeat()</a>
+   * @see <a href="http://msdn.microsoft.com/en-us/library/hh229428.aspx">MSDN: Observable.Repeat</a>
+   */
+  def repeat(count: Long, scheduler: Scheduler): Observable[T] = {
+    toScalaObservable[T](asJavaObservable.repeat(count, scheduler))
+  }
+
   /**
    * Converts an Observable into a [[rx.lang.scala.observables.BlockingObservable]] (an Observable with blocking
    * operators).

language-adaptors/rxjava-scala/src/test/scala/rx/lang/scala/CompletenessTest.scala

@@ -143,6 +143,8 @@ class CompletenessTest extends JUnitSuite {
       "mergeDelayError(Observable[_ <: T], Observable[_ <: T])" -> "mergeDelayError(Observable[U])",
       "mergeDelayError(Observable[_ <: Observable[_ <: T]])" -> "flattenDelayError(<:<[Observable[T], Observable[Observable[U]]])",
       "range(Int, Int)" -> "apply(Range)",
+      "repeat()" -> "repeat()",
+      "retry()" -> "retry()",
       "sequenceEqual(Observable[_ <: T], Observable[_ <: T])" -> "[use `(first zip second) map (p => p._1 == p._2)`]",
       "sequenceEqual(Observable[_ <: T], Observable[_ <: T], Func2[_ >: T, _ >: T, Boolean])" -> "[use `(first zip second) map (p => equality(p._1, p._2))`]",
       "sum(Observable[Integer])" -> "sum(Numeric[U])",