/*
 * 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 org.apache.xerces.xs;

/**
 *  The <code>StringList</code> is an immutable ordered collection of 
 * <code>GenericString</code>. 
 */
public interface StringList {
    /**
     *  The number of <code>GenericString</code>s in the list. The range of 
     * valid child object indices is 0 to <code>length-1</code> inclusive. 
     */
    public int getLength();

    /**
     *  Checks if the <code>GenericString</code> <code>item</code> is a member 
     * of this list. 
     * @param item  <code>GenericString</code> whose presence in this list is 
     *   to be tested. 
     * @return  True if this list contains the <code>GenericString</code> 
     *   <code>item</code>. 
     */
    public boolean contains(String item);

    /**
     *  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>GenericString</code> at the <code>index</code>th 
     *   position in the <code>StringList</code>, or <code>null</code> if 
     *   the index specified is not valid. 
     */
    public String item(int index);

}
