Fixed ZipWithIndex using mutable state (not pretty)

Author: AppliedDuality

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

@@ -310,9 +310,8 @@ trait Observable[+T]
    *         their index. Indices start at 0.
    */
   def zipWithIndex: Observable[(T, Int)] = {
-    val fScala: (T, Integer) => (T, Int) = (elem: T, index: Integer) => (elem, index)
-    val fJava : Func2[_ >: T, Integer, _ <: (T, Int)] = fScala
-    toScalaObservable[(T, Int)](asJavaObservable.mapWithIndex[(T, Int)](fJava))
+    var n = 0;
+    this.map(x => { val result = (x,n); n += 1; result })
   }
 
   /**

settings.gradle

@@ -3,7 +3,7 @@ include 'rxjava-core', \
 'language-adaptors:rxjava-groovy', \
 'language-adaptors:rxjava-clojure', \
 'language-adaptors:rxjava-jruby', \
-//'language-adaptors:rxjava-scala', \
+'language-adaptors:rxjava-scala', \
 //'language-adaptors:rxjava-kotlin', \
 'rxjava-contrib:rxjava-swing', \
 'rxjava-contrib:rxjava-android', \