/*
* The contents of this file are subject to the terms
* of the Common Development and Distribution License
* (the "License"). You may not use this file except
* in compliance with the License.
*
* You can obtain a copy of the license at
* https://jaxp.dev.java.net/CDDLv1.0.html.
* See the License for the specific language governing
* permissions and limitations under the License.
*
* When distributing Covered Code, include this CDDL
* HEADER in each file and include the License file at
* https://jaxp.dev.java.net/CDDLv1.0.html
* If applicable add the following below this CDDL HEADER
* with the fields enclosed by brackets "[]" replaced with
* your own identifying information: Portions Copyright
* [year] [name of copyright owner]
*/
/*
* $Id: XMLEntityReader.java,v 1.3 2005/11/03 17:02:21 jeffsuttor Exp $
* @(#)XPathFunction.java 1.13 05/11/17
*
* Copyright 2006 Sun Microsystems, Inc. All Rights Reserved.
*/
package javax.xml.xpath;
import java.util.List;
/**
* <p><code>XPathFunction</code> provides access to XPath functions.</p>
*
* <p>Functions are identified by QName and arity in XPath.</p>
*
* @author <a href="mailto:Norman.Walsh@Sun.com">Norman Walsh</a>
* @author <a href="mailto:Jeff.Suttor@Sun.com">Jeff Suttor</a>
* @version $Revision: 1.2 $, $Date: 2005/06/10 03:50:44 $
* @since 1.5
*/
public interface XPathFunction {
/**
* <p>Evaluate the function with the specified arguments.</p>
*
* <p>To the greatest extent possible, side-effects should be avoided in the
* definition of extension functions. The implementation evaluating an
* XPath expression is under no obligation to call extension functions in
* any particular order or any particular number of times.</p>
*
* @param args The arguments, <code>null</code> is a valid value.
*
* @return The result of evaluating the <code>XPath</code> function as an <code>Object</code>.
*
* @throws XPathFunctionException If <code>args</code> cannot be evaluated with this <code>XPath</code> function.
*/
public Object evaluate(List args)
throws XPathFunctionException;
}