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/*

 * This file is available under and governed by the GNU General Public

 * License version 2 only, as published by the Free Software Foundation.

 * However, the following notice accompanied the original version of this

 * file and, per its terms, should not be removed:

 *

 * Copyright (c) 2002 World Wide Web Consortium,

 * (Massachusetts Institute of Technology, Institut National de

 * Recherche en Informatique et en Automatique, Keio University). All

 * Rights Reserved. This program is distributed under the W3C's Software

 * Intellectual Property License. This program is distributed in the

 * hope that it will be useful, but WITHOUT ANY WARRANTY; without even

 * the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR

 * PURPOSE.

 * See W3C License http://www.w3.org/Consortium/Legal/ for more details.

 */

package org.w3c.dom.xpath;

/**

 * The <code>XPathNSResolver</code> interface permit <code>prefix</code>

 * strings in the expression to be properly bound to

 * <code>namespaceURI</code> strings. <code>XPathEvaluator</code> can

 * construct an implementation of <code>XPathNSResolver</code> from a node,

 * or the interface may be implemented by any application.

 * <p>See also the <a href='https://www.w3.org/TR/DOM-Level-3-XPath/'>Document Object Model (DOM) Level 3 XPath Specification</a>.

 */

public interface XPathNSResolver {

    /**

     * Look up the namespace URI associated to the given namespace prefix. The

     * XPath evaluator must never call this with a <code>null</code> or

     * empty argument, because the result of doing this is undefined.

     * @param prefix The prefix to look for.

     * @return Returns the associated namespace URI or <code>null</code> if

     *   none is found.

     */

    public String lookupNamespaceURI(String prefix);

}