--- /dev/null 2009-07-06 20:02:10.000000000 -0700 +++ new/src/share/classes/javax/lang/model/util/AbstractElementVisitor7.java 2010-04-29 22:39:15.000000000 -0700 @@ -0,0 +1,119 @@ +/* + * Copyright 2010 Sun Microsystems, Inc. All Rights Reserved. + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. + * + * This code is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2 only, as + * published by the Free Software Foundation. Sun designates this + * particular file as subject to the "Classpath" exception as provided + * by Sun in the LICENSE file that accompanied this code. + * + * This code 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 the GNU General Public License + * version 2 for more details (a copy is included in the LICENSE file that + * accompanied this code). + * + * You should have received a copy of the GNU General Public License version + * 2 along with this work; if not, write to the Free Software Foundation, + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. + * + * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, + * CA 95054 USA or visit www.sun.com if you need additional information or + * have any questions. + */ + +package javax.lang.model.util; + +import javax.lang.model.element.*; +import javax.annotation.processing.SupportedSourceVersion; +import javax.lang.model.element.*; +import static javax.lang.model.element.ElementKind.*; +import static javax.lang.model.SourceVersion.*; +import javax.lang.model.SourceVersion; + + +/** + * A skeletal visitor of program elements with default behavior + * appropriate for the {@link SourceVersion#RELEASE_7 RELEASE_7} + * source version. + * + *

WARNING: The {@code ElementVisitor} interface + * implemented by this class may have methods added to it in the + * future to accommodate new, currently unknown, language structures + * added to future versions of the Java™ programming language. + * Therefore, methods whose names begin with {@code "visit"} may be + * added to this class in the future; to avoid incompatibilities, + * classes which extend this class should not declare any instance + * methods with names beginning with {@code "visit"}. + * + *

When such a new visit method is added, the default + * implementation in this class will be to call the {@link + * #visitUnknown visitUnknown} method. A new abstract element visitor + * class will also be introduced to correspond to the new language + * level; this visitor will have different default behavior for the + * visit method in question. When the new visitor is introduced, all + * or portions of this visitor may be deprecated. + * + * @param the return type of this visitor's methods. Use {@link + * Void} for visitors that do not need to return results. + * @param

the type of the additional parameter to this visitor's + * methods. Use {@code Void} for visitors that do not need an + * additional parameter. + * + * @see AbstractElementVisitor6 + * @since 1.7 + */ +@SupportedSourceVersion(RELEASE_7) +public abstract class AbstractElementVisitor7 implements ElementVisitor { + /** + * Constructor for concrete subclasses to call. + */ + protected AbstractElementVisitor7(){} + + /** + * Visits any program element as if by passing itself to that + * element's {@link Element#accept accept} method. The invocation + * {@code v.visit(elem)} is equivalent to {@code elem.accept(v, + * p)}. + * + * @param e the element to visit + * @param p a visitor-specified parameter + * @return a visitor-specified result + */ + public final R visit(Element e, P p) { + return e.accept(this, p); + } + + /** + * Visits any program element as if by passing itself to that + * element's {@link Element#accept accept} method and passing + * {@code null} for the additional parameter. The invocation + * {@code v.visit(elem)} is equivalent to {@code elem.accept(v, + * null)}. + * + * @param e the element to visit + * @return a visitor-specified result + */ + public final R visit(Element e) { + return e.accept(this, null); + } + + /** + * {@inheritDoc} + * + *

The default implementation of this method in + * {@code AbstractElementVisitor7} will always throw + * {@code UnknownElementException}. + * This behavior is not required of a subclass. + * + * @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 + */ + public R visitUnknown(Element e, P p) { + throw new UnknownElementException(e, p); + } +}