Switching to the new build system and to the ne...

Switching to the new build system and to the new build system. This is a
MAJOR commit, so be careful when updating.

1 files changed, 45 insertions, 0 deletions

diff --git a/src/library/scala/collection/mutable/Publisher.scala b/src/library/scala/collection/mutable/Publisher.scala
new file mode 100644
index 0000000000..ee442eccd2
--- /dev/null
+++ b/src/library/scala/collection/mutable/Publisher.scala
@@ -0,0 +1,45 @@
+/*                     __                                               *\
+**     ________ ___   / /  ___     Scala API                            **
+**    / __/ __// _ | / /  / _ |    (c) 2003, LAMP/EPFL                  **
+**  __\ \/ /__/ __ |/ /__/ __ |                                         **
+** /____/\___/_/ |_/____/_/ | |                                         **
+**                          |/                                          **
+** $Id$
+\*                                                                      */
+
+package scala.collection.mutable;
+
+
+/** <code>Publisher[A,This]</code> objects publish events of type <code>A</code>
+ *  to all registered subscribers. When subscribing, a subscriber may specify
+ *  a filter which can be used to constrain the number of events sent to the
+ *  subscriber. Subscribers may suspend their subscription, or reactivate a
+ *  suspended subscription. Class <code>Publisher</code> is typically used
+ *  as a mixin. The type variable <code>This</code> models self types.
+ *
+ *  @author  Matthias Zenger
+ *  @version 1.0, 08/07/2003
+ */
+[_trait_] abstract class Publisher[A, This <: Publisher[A, This]]: This {
+    private val filters = new HashMap[Subscriber[A, This],
+                                      scala.collection.mutable.Set[A => Boolean]]
+                            with MultiMap[Subscriber[A, This], A => Boolean];
+    private val suspended = new HashSet[Subscriber[A, This]];
+
+    def subscribe(sub: Subscriber[A, This]): Unit = subscribe(sub, (event => true));
+
+    def subscribe(sub: Subscriber[A, This], filter: A => Boolean): Unit =
+        filters.add(sub, filter);
+
+    def suspendSubscription(sub: Subscriber[A, This]): Unit = suspended += sub;
+
+    def activateSubscription(sub: Subscriber[A, This]): Unit = suspended -= sub;
+
+    def removeSubscription(sub: Subscriber[A, This]): Unit = filters -= sub;
+
+    def removeSubscriptions: Unit = filters.clear;
+
+    protected def publish(event: A): Unit =
+        filters.keys.foreach(sub =>
+            if (filters.entryExists(sub, (p => p(event)))) sub.notify(this, event));
+}