1 files changed, 50 insertions, 0 deletions
diff --git a/src/library/scala/collection/mutable/ImmutableSetAdaptor.scala b/src/library/scala/collection/mutable/ImmutableSetAdaptor.scala
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+++ b/src/library/scala/collection/mutable/ImmutableSetAdaptor.scala
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+/*                     __                                               *\
+**     ________ ___   / /  ___     Scala API                            **
+**    / __/ __// _ | / /  / _ |    (c) 2003, LAMP/EPFL                  **
+**  __\ \/ /__/ __ |/ /__/ __ |                                         **
+** /____/\___/_/ |_/____/_/ | |                                         **
+**                          |/                                          **
+** $Id$
+\*                                                                      */
+
+package scala.collection.mutable;
+
+
+/** This class can be used as an adaptor to create mutable sets from
+ *  immutable set implementations. Only method <code>empty</code> has
+ *  to be redefined if the immutable set on which this mutable set is
+ *  originally based is not empty. <code>empty</code> is supposed to
+ *  return the representation of an empty set.
+ *
+ *  @author  Matthias Zenger
+ *  @version 1.0, 21/07/2003
+ */
+[serializable]
+class ImmutableSetAdaptor[A](s: scala.collection.immutable.Set[A]) extends Set[A] {
+
+    protected var set = s;
+
+    def size: Int = set.size;
+
+    override def isEmpty: Boolean = set.isEmpty;
+
+    def contains(elem: A): Boolean = set.contains(elem);
+
+    override def foreach(f: A => Unit): Unit = set.foreach(f);
+
+    override def exists(p: A => Boolean): Boolean = set.exists(p);
+
+    override def toList: List[A] = set.toList;
+
+    override def toString() = set.toString();
+
+    def elements: Iterator[A] = set.elements;
+
+    def +=(elem: A): Unit = { set = set + elem; }
+
+    def -=(elem: A): Unit = { set = set - elem; }
+
+    def clear: Unit = { set = empty; }
+
+    protected def empty: scala.collection.immutable.Set[A] = s;
+}