1 /*
2 * Copyright (c) 2019, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 package javax.lang.model.util;
27
28 import javax.lang.model.element.*;
29 import javax.annotation.processing.SupportedSourceVersion;
30 import static javax.lang.model.SourceVersion.*;
31 import javax.lang.model.SourceVersion;
32
33 /**
34 * {@preview Associated with records, a preview feature of the Java language.
35 *
36 * This class is associated with <i>records</i>, a preview
37 * feature of the Java language. Preview features
38 * may be removed in a future release, or upgraded to permanent
39 * features of the Java language.}
40 *
41 * A visitor of program elements based on their {@linkplain
42 * ElementKind kind} with default behavior appropriate for the {@link
43 * SourceVersion#RELEASE_14 RELEASE_14} source version.
44 *
45 * For {@linkplain
46 * Element elements} <code><i>Xyz</i></code> that may have more than one
47 * kind, the <code>visit<i>Xyz</i></code> methods in this class delegate
48 * to the <code>visit<i>Xyz</i>As<i>Kind</i></code> method corresponding to the
49 * first argument's kind. The <code>visit<i>Xyz</i>As<i>Kind</i></code> methods
50 * call {@link #defaultAction defaultAction}, passing their arguments
51 * to {@code defaultAction}'s corresponding parameters.
52 *
53 * <p> Methods in this class may be overridden subject to their
54 * general contract. Note that annotating methods in concrete
55 * subclasses with {@link java.lang.Override @Override} will help
56 * ensure that methods are overridden as intended.
57 *
58 * <p> <b>WARNING:</b> The {@code ElementVisitor} interface
59 * implemented by this class may have methods added to it or the
60 * {@code ElementKind} {@code enum} used in this case may have
61 * constants added to it in the future to accommodate new, currently
62 * unknown, language structures added to future versions of the
63 * Java™ programming language. Therefore, methods whose names
64 * begin with {@code "visit"} may be added to this class in the
65 * future; to avoid incompatibilities, classes which extend this class
66 * should not declare any instance methods with names beginning with
67 * {@code "visit"}.
68 *
69 * <p>When such a new visit method is added, the default
70 * implementation in this class will be to call the {@link
71 * #visitUnknown visitUnknown} method. A new abstract element kind
72 * visitor class will also be introduced to correspond to the new
73 * language level; this visitor will have different default behavior
74 * for the visit method in question. When the new visitor is
75 * introduced, all or portions of this visitor may be deprecated.
76 *
77 * @param <R> the return type of this visitor's methods. Use {@link
78 * Void} for visitors that do not need to return results.
79 * @param <P> the type of the additional parameter to this visitor's
80 * methods. Use {@code Void} for visitors that do not need an
81 * additional parameter.
82 *
83 * @see ElementKindVisitor6
84 * @see ElementKindVisitor7
85 * @see ElementKindVisitor8
86 * @see ElementKindVisitor9
87 * @since 14
88 */
89 @jdk.internal.PreviewFeature(feature=jdk.internal.PreviewFeature.Feature.RECORDS,
90 essentialAPI=false)
91 @SupportedSourceVersion(RELEASE_15)
92 public class ElementKindVisitor14<R, P> extends ElementKindVisitor9<R, P> {
93 /**
94 * Constructor for concrete subclasses; uses {@code null} for the
95 * default value.
96 */
97 protected ElementKindVisitor14() {
98 super(null);
99 }
100
101 /**
102 * Constructor for concrete subclasses; uses the argument for the
103 * default value.
104 *
105 * @param defaultValue the value to assign to {@link #DEFAULT_VALUE}
106 */
107 protected ElementKindVisitor14(R defaultValue) {
108 super(defaultValue);
109 }
110
111 /**
112 * {@inheritDoc}
113 *
114 * @implSpec This implementation calls {@code defaultAction}.
115 *
116 * @param e the element to visit
117 * @param p a visitor-specified parameter
118 * @return the result of {@code defaultAction}
119 */
120 @SuppressWarnings("preview")
121 @Override
122 public R visitRecordComponent(RecordComponentElement e, P p) {
123 return defaultAction(e, p);
124 }
125
126 /**
127 * {@inheritDoc}
128 *
129 * @implSpec This implementation calls {@code defaultAction}.
130 *.
131 * @param e the element to visit
132 * @param p a visitor-specified parameter
133 * @return the result of {@code defaultAction}
134 */
135 @Override
136 public R visitTypeAsRecord(TypeElement e, P p) {
137 return defaultAction(e, p);
138 }
139
140 /**
141 * Visits a {@code BINDING_VARIABLE} variable element.
142 *
143 * @implSpec This implementation calls {@code defaultAction}.
144 *
145 * @param e {@inheritDoc}
146 * @param p {@inheritDoc}
147 * @return the result of {@code defaultAction}
148 *
149 * @since 14
150 */
151 @Override
152 public R visitVariableAsBindingVariable(VariableElement e, P p) {
153 return defaultAction(e, p);
154 }
155 }