commons-xml/java/external/src/javax/xml/xpath/XPathFunction.java
2005-04-08 10:39:14 +00:00

51 lines
1.7 KiB
Java

/*
* 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.
*/
// $Id$
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 $Revision$, $Date$
* @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;
}