unzip(3) on view now returns view.

* Added unzip and unzip3 to TraversableViewLike
* Added partest tests for unzip on views returning specific collection types.

Closes SI-5053
Review by @paulp

1 files changed, 6 insertions, 0 deletions

diff --git a/src/library/scala/collection/TraversableViewLike.scala b/src/library/scala/collection/TraversableViewLike.scala
index 60870cc835..fbecad98fe 100644
--- a/src/library/scala/collection/TraversableViewLike.scala
+++ b/src/library/scala/collection/TraversableViewLike.scala
@@ -192,6 +192,12 @@ trait TraversableViewLike[+A,
   override def groupBy[K](f: A => K): immutable.Map[K, This] =
     thisSeq groupBy f mapValues (xs => newForced(xs))
 
+  override def unzip[A1, A2](implicit asPair: A => (A1, A2)) =
+    (newMapped(x => asPair(x)._1), newMapped(x => asPair(x)._2))  // TODO - Performance improvements.
+
+  override def unzip3[A1, A2, A3](implicit asTriple: A => (A1, A2, A3)) =
+    (newMapped(x => asTriple(x)._1), newMapped(x => asTriple(x)._2), newMapped(x => asTriple(x)._3))  // TODO - Performance improvements.
+
   override def toString = viewToString
 }