/*
 * reserved comment block
 * DO NOT REMOVE OR ALTER!
 */
/*
 * Copyright 2003,2004 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.
 */

package com.sun.org.apache.xerces.internal.xs;

/**
 *  The <code>XSObjectList</code> interface provides the abstraction of an
 * immutable ordered collection of <code>XSObject</code>s, without defining
 * or constraining how this collection is implemented.
 */
public interface XSObjectList {
    /**
     *  The number of <code>XSObjects</code> in the list. The range of valid
     * child object indices is 0 to <code>length-1</code> inclusive.
     */
    public int getLength();

    /**
     *  Returns the <code>index</code>th item in the collection or
     * <code>null</code> if <code>index</code> is greater than or equal to
     * the number of objects in the list. The index starts at 0.
     * @param index  index into the collection.
     * @return  The <code>XSObject</code> at the <code>index</code>th
     *   position in the <code>XSObjectList</code>, or <code>null</code> if
     *   the index specified is not valid.
     */
    public XSObject item(int index);

}
