fixed #2500: refactoring collections so that a ...

fixed #2500: refactoring collections so that a `collection.{Map|SortedMap|SortedSet}` can be built from the corresponding collection (thus, do not require the immutable one)

pulling up newBuilder method from Immutable*Factory to *Factory, and
inheriting *Factory in scala.collection companion objects, instead of
the Immutable*Factory this way, you can, e.g., build a collection.Map
from a collection.Map (instead of requiring an immutable.Map)

1 files changed, 4 insertions, 3 deletions

diff --git a/src/library/scala/collection/Map.scala b/src/library/scala/collection/Map.scala
index b53786308b..f947e4e5da 100644
--- a/src/library/scala/collection/Map.scala
+++ b/src/library/scala/collection/Map.scala
@@ -35,7 +35,7 @@ import generic._
  * @note If you do not have specific implementations for `add` and `-` in mind,
  *       you might consider inheriting from <code>DefaultMap</code> instead.
  *
- * @note Of you additions and mutations return the same kind of map as the map
+ * @note If your additions and mutations return the same kind of map as the map
  *       you are defining, you should inherit from <code>MapLike</code> as well.
  *
  * @since 1
@@ -48,7 +48,8 @@ trait Map[A, +B] extends Iterable[(A, B)] with MapLike[A, B, Map[A, B]] {
  *
  * @since 2.5
  */
-object Map extends ImmutableMapFactory[immutable.Map] {
-  def empty[A, B]: immutable.Map[A, B] = immutable.Map.empty
+object Map extends MapFactory[Map] {
+  def empty[A, B]: Map[A, B] = immutable.Map.empty
+
   implicit def canBuildFrom[A, B]: CanBuildFrom[Coll, (A, B), Map[A, B]] = new MapCanBuildFrom[A, B]
 }