/*
 * Copyright 2005 The Apache Software Foundation.
 *
 *  Licensed under the Apache License, Version 2.0 (the "License");
 *  you may not use this file except in compliance with the License.
 *  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 *
 */
/*
 * Copyright 2005 Sun Microsystems, Inc. All rights reserved.
 */
/*
 * $Id$
 */
package javax.xml.crypto;

import java.util.Iterator;

/**
 * An abstract representation of a <code>Data</code> type containing a 
 * node-set. The type (class) and ordering of the nodes contained in the set 
 * are not defined by this class; instead that behavior should be 
 * defined by <code>NodeSetData</code> subclasses.
 *
 * @author Sean Mullan
 * @author JSR 105 Expert Group
 */
public interface NodeSetData extends Data {

    /**
     * Returns a read-only iterator over the nodes contained in this 
     * <code>NodeSetData</code> in 
     * <a href="http://www.w3.org/TR/1999/REC-xpath-19991116#dt-document-order">
     * document order</a>. Attempts to modify the returned iterator
     * via the <code>remove</code> method throw 
     * <code>UnsupportedOperationException</code>.
     *
     * @return an <code>Iterator</code> over the nodes in this 
     *    <code>NodeSetData</code> in document order
     */
    Iterator iterator();
}