1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/src/share/classes/javax/lang/model/util/ElementScanner8.java Tue Jul 05 16:37:24 2011 -0700
1.3 @@ -0,0 +1,109 @@
1.4 +/*
1.5 + * Copyright (c) 2011, Oracle and/or its affiliates. All rights reserved.
1.6 + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
1.7 + *
1.8 + * This code is free software; you can redistribute it and/or modify it
1.9 + * under the terms of the GNU General Public License version 2 only, as
1.10 + * published by the Free Software Foundation. Oracle designates this
1.11 + * particular file as subject to the "Classpath" exception as provided
1.12 + * by Oracle in the LICENSE file that accompanied this code.
1.13 + *
1.14 + * This code is distributed in the hope that it will be useful, but WITHOUT
1.15 + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
1.16 + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
1.17 + * version 2 for more details (a copy is included in the LICENSE file that
1.18 + * accompanied this code).
1.19 + *
1.20 + * You should have received a copy of the GNU General Public License version
1.21 + * 2 along with this work; if not, write to the Free Software Foundation,
1.22 + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
1.23 + *
1.24 + * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
1.25 + * or visit www.oracle.com if you need additional information or have any
1.26 + * questions.
1.27 + */
1.28 +
1.29 +package javax.lang.model.util;
1.30 +
1.31 +import javax.lang.model.element.*;
1.32 +import javax.annotation.processing.SupportedSourceVersion;
1.33 +import static javax.lang.model.element.ElementKind.*;
1.34 +import javax.lang.model.SourceVersion;
1.35 +import static javax.lang.model.SourceVersion.*;
1.36 +
1.37 +
1.38 +/**
1.39 + * A scanning visitor of program elements with default behavior
1.40 + * appropriate for the {@link SourceVersion#RELEASE_8 RELEASE_8}
1.41 + * source version. The <tt>visit<i>XYZ</i></tt> methods in this
1.42 + * class scan their component elements by calling {@code scan} on
1.43 + * their {@linkplain Element#getEnclosedElements enclosed elements},
1.44 + * {@linkplain ExecutableElement#getParameters parameters}, etc., as
1.45 + * indicated in the individual method specifications. A subclass can
1.46 + * control the order elements are visited by overriding the
1.47 + * <tt>visit<i>XYZ</i></tt> methods. Note that clients of a scanner
1.48 + * may get the desired behavior be invoking {@code v.scan(e, p)} rather
1.49 + * than {@code v.visit(e, p)} on the root objects of interest.
1.50 + *
1.51 + * <p>When a subclass overrides a <tt>visit<i>XYZ</i></tt> method, the
1.52 + * new method can cause the enclosed elements to be scanned in the
1.53 + * default way by calling <tt>super.visit<i>XYZ</i></tt>. In this
1.54 + * fashion, the concrete visitor can control the ordering of traversal
1.55 + * over the component elements with respect to the additional
1.56 + * processing; for example, consistently calling
1.57 + * <tt>super.visit<i>XYZ</i></tt> at the start of the overridden
1.58 + * methods will yield a preorder traversal, etc. If the component
1.59 + * elements should be traversed in some other order, instead of
1.60 + * calling <tt>super.visit<i>XYZ</i></tt>, an overriding visit method
1.61 + * should call {@code scan} with the elements in the desired order.
1.62 + *
1.63 + * <p> Methods in this class may be overridden subject to their
1.64 + * general contract. Note that annotating methods in concrete
1.65 + * subclasses with {@link java.lang.Override @Override} will help
1.66 + * ensure that methods are overridden as intended.
1.67 + *
1.68 + * <p> <b>WARNING:</b> The {@code ElementVisitor} interface
1.69 + * implemented by this class may have methods added to it in the
1.70 + * future to accommodate new, currently unknown, language structures
1.71 + * added to future versions of the Java™ programming language.
1.72 + * Therefore, methods whose names begin with {@code "visit"} may be
1.73 + * added to this class in the future; to avoid incompatibilities,
1.74 + * classes which extend this class should not declare any instance
1.75 + * methods with names beginning with {@code "visit"}.
1.76 + *
1.77 + * <p>When such a new visit method is added, the default
1.78 + * implementation in this class will be to call the {@link
1.79 + * #visitUnknown visitUnknown} method. A new element scanner visitor
1.80 + * class will also be introduced to correspond to the new language
1.81 + * level; this visitor will have different default behavior for the
1.82 + * visit method in question. When the new visitor is introduced, all
1.83 + * or portions of this visitor may be deprecated.
1.84 + *
1.85 + * @param <R> the return type of this visitor's methods. Use {@link
1.86 + * Void} for visitors that do not need to return results.
1.87 + * @param <P> the type of the additional parameter to this visitor's
1.88 + * methods. Use {@code Void} for visitors that do not need an
1.89 + * additional parameter.
1.90 + *
1.91 + * @see ElementScanner6
1.92 + * @see ElementScanner7
1.93 + * @since 1.8
1.94 + */
1.95 +@SupportedSourceVersion(RELEASE_8)
1.96 +public class ElementScanner8<R, P> extends ElementScanner7<R, P> {
1.97 + /**
1.98 + * Constructor for concrete subclasses; uses {@code null} for the
1.99 + * default value.
1.100 + */
1.101 + protected ElementScanner8(){
1.102 + super(null);
1.103 + }
1.104 +
1.105 + /**
1.106 + * Constructor for concrete subclasses; uses the argument for the
1.107 + * default value.
1.108 + */
1.109 + protected ElementScanner8(R defaultValue){
1.110 + super(defaultValue);
1.111 + }
1.112 +}
