Specialize genTraversableOnce2jsArray for js.ArrayOps and js.WrappedArray.

sjrd · sjrd · commit 0d2402b5ecd5 · 2014-09-26T16:13:50.000+02:00
In a sense, this is as if .toJSArray were overridden in js.ArrayOps
and js.WrappedArray, which makes total sense. But since .toJSArray
is a pimp, we need to make this specialization directly in its
implementation.
diff --git a/library/src/main/scala/scala/scalajs/runtime/package.scala b/library/src/main/scala/scala/scalajs/runtime/package.scala
@@ -6,9 +6,14 @@ package object runtime {
 
   @inline final def genTraversableOnce2jsArray[A](
       col: GenTraversableOnce[A]): js.Array[A] = {
-    val result = new js.Array[A]
-    col.foreach(x => result.push(x))
-    result
+    col match {
+      case col: js.ArrayOps[A]     => col.result()
+      case col: js.WrappedArray[A] => col.array
+      case _ =>
+        val result = new js.Array[A]
+        col.foreach(x => result.push(x))
+        result
+    }
   }
 
   /** Information about the environment Scala.js runs in. */
