cleaned up collection builder framework

1 files changed, 18 insertions, 0 deletions

diff --git a/src/library/scala/collection/generic/MapFactory.scala b/src/library/scala/collection/generic/MapFactory.scala
new file mode 100644
index 0000000000..067f22dbf1
--- /dev/null
+++ b/src/library/scala/collection/generic/MapFactory.scala
@@ -0,0 +1,18 @@
+package scala.collection.generic
+
+/** A template for companion objects of mutable.Map and subclasses thereof.
+ */
+abstract class MapFactory[CC[A, B] <: Map[A, B] with MapTemplate[A, B, CC[A, B]]] {
+
+  type Coll = CC[_, _]
+
+  def newBuilder[A, B]: Builder[(A, B), CC[A, B]]
+
+  def empty[A, B]: CC[A, B]
+
+  def apply[A, B](elems: (A, B)*): CC[A, B] = (newBuilder[A, B] ++= elems).result
+
+  class MapBuilderFactory[A, B] extends BuilderFactory[(A, B), CC[A, B], Coll] {
+    def apply(from: Coll) = newBuilder[A, B]
+  }
+}