immutable.Map keySet returns immutable.Set.

3 files changed, 7 insertions, 3 deletions

diff --git a/src/library/scala/collection/immutable/MapLike.scala b/src/library/scala/collection/immutable/MapLike.scala
index bbad195687..0e2723cf2b 100644
--- a/src/library/scala/collection/immutable/MapLike.scala
+++ b/src/library/scala/collection/immutable/MapLike.scala
@@ -50,8 +50,6 @@ trait MapLike[A, +B, +This <: MapLike[A, B, This] with Map[A, B]]
   extends scala.collection.MapLike[A, B, This]
 { self =>
 
-  import scala.collection.Traversable
-
   /** A new immutable map containing updating this map with a given key/value mapping.
    *  @param    key the key
    *  @param    value the value
@@ -110,6 +108,11 @@ trait MapLike[A, +B, +This <: MapLike[A, B, This] with Map[A, B]]
     def get(key: A) = self.get(key).map(f)
   }
 
+  /** Collects all keys of this map in a set.
+   *  @return  a set containing all keys of this map.
+   */
+  override def keySet: immutable.Set[A] = immutable.Set.empty ++ (this map (_._1))
+
   /** This function transforms all the values of mappings contained
    *  in this map with function `f`.
    *
diff --git a/src/library/scala/collection/immutable/MapProxy.scala b/src/library/scala/collection/immutable/MapProxy.scala
index fa0b097070..8313e4d143 100644
--- a/src/library/scala/collection/immutable/MapProxy.scala
+++ b/src/library/scala/collection/immutable/MapProxy.scala
@@ -35,6 +35,7 @@ trait MapProxy[A, +B] extends Map[A, B] with MapProxyLike[A, B, Map[A, B]] {
   override def + [B1 >: B](elem1: (A, B1), elem2: (A, B1), elems: (A, B1) *) = newProxy(self.+(elem1, elem2, elems: _*))
   override def ++[B1 >: B](xs: TraversableOnce[(A, B1)]) = newProxy(self ++ xs)
 
+  override def keySet: immutable.Set[A] = new SetProxy[A] { val self = MapProxy.this.self.keySet }
   override def filterKeys(p: A => Boolean) = self.filterKeys(p)
   override def mapValues[C](f: B => C) = self.mapValues(f)
 }
diff --git a/src/library/scala/collection/immutable/SortedMap.scala b/src/library/scala/collection/immutable/SortedMap.scala
index f49c4a9986..aa30932bb7 100644
--- a/src/library/scala/collection/immutable/SortedMap.scala
+++ b/src/library/scala/collection/immutable/SortedMap.scala
@@ -36,8 +36,8 @@ trait SortedMap[A, +B] extends Map[A, B]
     SortedMap.newBuilder[A, B]
 
   override def empty: SortedMap[A, B] = SortedMap.empty
-
   override def updated [B1 >: B](key: A, value: B1): SortedMap[A, B1] = this + ((key, value))
+  override def keySet: immutable.SortedSet[A] = SortedSet.empty ++ (this map (_._1))
 
   /** Add a key/value pair to this map.
    *  @param    kv the key/value pair