Index: lucene/core/src/java/org/apache/lucene/search/Filter.java
===================================================================
--- lucene/core/src/java/org/apache/lucene/search/Filter.java	(revision 1633246)
+++ lucene/core/src/java/org/apache/lucene/search/Filter.java	(working copy)
@@ -56,4 +56,16 @@
    *         in the case an <i>empty</i> {@link DocIdSet} is returned.
    */
   public abstract DocIdSet getDocIdSet(LeafReaderContext context, Bits acceptDocs) throws IOException;
+
+  /**
+   * Returns an iterator matching documents.
+   */
+  public DocIdSetIterator iterator(LeafReaderContext context, Bits acceptDocs) throws IOException {
+    DocIdSet set = getDocIdSet(context, acceptDocs);
+    if (set == null) {
+      return null;
+    } else {
+      return set.iterator();
+    }
+  }
 }
Index: lucene/core/src/java/org/apache/lucene/search/Weight.java
===================================================================
--- lucene/core/src/java/org/apache/lucene/search/Weight.java	(revision 1633246)
+++ lucene/core/src/java/org/apache/lucene/search/Weight.java	(working copy)
@@ -34,7 +34,7 @@
  * {@link org.apache.lucene.index.LeafReader} dependent state should reside in the {@link Scorer}.
  * <p>
  * Since {@link Weight} creates {@link Scorer} instances for a given
- * {@link org.apache.lucene.index.LeafReaderContext} ({@link #scorer(org.apache.lucene.index.LeafReaderContext, Bits)})
+ * {@link org.apache.lucene.index.LeafReaderContext} ({@link #iterator(org.apache.lucene.index.LeafReaderContext, Bits)})
  * callers must maintain the relationship between the searcher's top-level
  * {@link IndexReaderContext} and the context used to create a {@link Scorer}.
  * <p>
@@ -49,12 +49,12 @@
  * <li>The query normalization factor is passed to {@link #normalize(float, float)}. At
  * this point the weighting is complete.
  * <li>A <code>Scorer</code> is constructed by
- * {@link #scorer(org.apache.lucene.index.LeafReaderContext, Bits)}.
+ * {@link #iterator(org.apache.lucene.index.LeafReaderContext, Bits)}.
  * </ol>
  *
  * @since 2.9
  */
-public abstract class Weight {
+public abstract class Weight extends Filter {

   /**
    * An explanation of the score computation for the named document.
@@ -75,6 +75,21 @@
   /** Assigns the query normalization factor and boost from parent queries to this. */
   public abstract void normalize(float norm, float topLevelBoost);

+  @Override
+  public final DocIdSet getDocIdSet(final LeafReaderContext context, final Bits acceptDocs) throws IOException {
+    return new DocIdSet() {
+      @Override
+      public long ramBytesUsed() {
+        return 0;
+      }
+
+      @Override
+      public DocIdSetIterator iterator() throws IOException {
+        return Weight.this.iterator(context, acceptDocs);
+      }
+    };
+  }
+
   /**
    * Returns a {@link Scorer} which scores documents in/out-of order according
    * to <code>scoreDocsInOrder</code>.
@@ -96,7 +111,7 @@
    * @return a {@link Scorer} which scores documents in/out-of order.
    * @throws IOException if there is a low-level I/O error
    */
-  public abstract Scorer scorer(LeafReaderContext context, Bits acceptDocs) throws IOException;
+  public abstract Scorer iterator(LeafReaderContext context, Bits acceptDocs) throws IOException;

   /**
    * Optional method, to return a {@link BulkScorer} to
@@ -127,7 +142,7 @@
    */
   public BulkScorer bulkScorer(LeafReaderContext context, boolean scoreDocsInOrder, Bits acceptDocs) throws IOException {

-    Scorer scorer = scorer(context, acceptDocs);
+    Scorer scorer = iterator(context, acceptDocs);
     if (scorer == null) {
       // No docs match
       return null;