001/*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements.  See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License.  You may obtain a copy of the License at
008 *
009 *     http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017package org.apache.commons.jxpath;
018
019import java.util.Set;
020
021/**
022 * A group of Function objects sharing a common namespace or a set of
023 * common namespaces. Use the classes
024 * {@link ClassFunctions ClassFunctions} and
025 * {@link PackageFunctions PackageFunctions}
026 * to register extension functions implemented as Java methods.
027 *
028 * @author Dmitri Plotnikov
029 * @version $Revision: 652845 $ $Date: 2008-05-02 13:46:46 -0400 (Fri, 02 May 2008) $
030 */
031public interface Functions {
032
033    /**
034     * Returns all namespaces in which this function collection defines
035     * functions.
036     * @return Set
037     */
038    Set getUsedNamespaces();
039
040    /**
041     * Returns a Function, if any, for the specified namespace,
042     * name and parameter types.
043     * @param namespace ns
044     * @param name function name
045     * @param parameters Object[]
046     * @return Function
047     */
048    Function getFunction(String namespace, String name, Object[] parameters);
049}