2362N/A * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved. 0N/A * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 0N/A * This code is free software; you can redistribute it and/or modify it 0N/A * under the terms of the GNU General Public License version 2 only, as 0N/A * published by the Free Software Foundation. Oracle designates this 0N/A * particular file as subject to the "Classpath" exception as provided 0N/A * by Oracle in the LICENSE file that accompanied this code. 0N/A * This code is distributed in the hope that it will be useful, but WITHOUT 0N/A * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 0N/A * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 0N/A * version 2 for more details (a copy is included in the LICENSE file that 0N/A * accompanied this code). 0N/A * You should have received a copy of the GNU General Public License version 0N/A * 2 along with this work; if not, write to the Free Software Foundation, 2362N/A * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 2362N/A * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 0N/A * or visit www.oracle.com if you need additional information or have any 0N/A * A visitor of program elements, in the style of the visitor design 0N/A * pattern. Classes implementing this interface are used to operate 0N/A * on an element when the kind of element is unknown at compile time. 0N/A * When a visitor is passed to an element's {@link Element#accept 0N/A * accept} method, the <tt>visit<i>XYZ</i></tt> method most applicable 0N/A * to that element is invoked. 0N/A * <p> Classes implementing this interface may or may not throw a 0N/A * {@code NullPointerException} if the additional parameter {@code p} 0N/A * is {@code null}; see documentation of the implementing class for 0N/A * <p> <b>WARNING:</b> It is possible that methods will be added to 0N/A * this interface to accommodate new, currently unknown, language 0N/A * structures added to future versions of the Java™ programming 0N/A * language. Therefore, visitor classes directly implementing this 0N/A * interface may be source incompatible with future versions of the * platform. To avoid this source incompatibility, visitor * implementations are encouraged to instead extend the appropriate * abstract visitor class that implements this interface. However, an * API should generally use this visitor interface as the type for * parameters, return type, etc. rather than one of the abstract * @param <R> the return type of this visitor's methods. Use {@link * Void} for visitors that do not need to return results. * @param <P> the type of the additional parameter to this visitor's * methods. Use {@code Void} for visitors that do not need an * @author Joseph D. Darcy * @author Peter von der Ahé * @see AbstractElementVisitor6 * @see AbstractElementVisitor7 * @param e the element to visit * @param p a visitor-specified parameter * @return a visitor-specified result * A convenience method equivalent to {@code v.visit(e, null)}. * @param e the element to visit * @return a visitor-specified result * Visits a package element. * @param e the element to visit * @param p a visitor-specified parameter * @return a visitor-specified result * @param e the element to visit * @param p a visitor-specified parameter * @return a visitor-specified result * Visits a variable element. * @param e the element to visit * @param p a visitor-specified parameter * @return a visitor-specified result * Visits an executable element. * @param e the element to visit * @param p a visitor-specified parameter * @return a visitor-specified result * Visits a type parameter element. * @param e the element to visit * @param p a visitor-specified parameter * @return a visitor-specified result * Visits an unknown kind of element. * This can occur if the language evolves and new kinds * of elements are added to the {@code Element} hierarchy. * @param e the element to visit * @param p a visitor-specified parameter * @return a visitor-specified result * @throws UnknownElementException * a visitor implementation may optionally throw this exception