1 /*
2 * Copyright (c) 2011, 2018, 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.annotation.processing.SupportedSourceVersion;
29 import javax.lang.model.SourceVersion;
30 import javax.lang.model.type.*;
31 import static javax.lang.model.SourceVersion.*;
32
33 /**
34 * A visitor of types based on their {@linkplain TypeKind kind} with
35 * default behavior appropriate for source versions {@link
36 * SourceVersion#RELEASE_9 RELEASE_9} through {@link
37 * SourceVersion#RELEASE_13 RELEASE_13}.
38 *
39 * For {@linkplain
40 * TypeMirror types} <code><i>Xyz</i></code> that may have more than one
41 * kind, the <code>visit<i>Xyz</i></code> methods in this class delegate
42 * to the <code>visit<i>Xyz</i>As<i>Kind</i></code> method corresponding to the
43 * first argument's kind. The <code>visit<i>Xyz</i>As<i>Kind</i></code> methods
44 * call {@link #defaultAction defaultAction}, passing their arguments
45 * to {@code defaultAction}'s corresponding parameters.
46 *
47 * <p> Methods in this class may be overridden subject to their
48 * general contract. Note that annotating methods in concrete
49 * subclasses with {@link java.lang.Override @Override} will help
50 * ensure that methods are overridden as intended.
51 *
52 * <p> <b>WARNING:</b> The {@code TypeVisitor} interface implemented
53 * by this class may have methods added to it in the future to
54 * accommodate new, currently unknown, language structures added to
55 * future versions of the Java™ programming language.
56 * Therefore, methods whose names begin with {@code "visit"} may be
57 * added to this class in the future; to avoid incompatibilities,
58 * classes which extend this class should not declare any instance
59 * methods with names beginning with {@code "visit"}.
60 *
61 * <p>When such a new visit method is added, the default
62 * implementation in this class will be to call the {@link
63 * #visitUnknown visitUnknown} method. A new type kind visitor class
64 * will also be introduced to correspond to the new language level;
65 * this visitor will have different default behavior for the visit
66 * method in question. When the new visitor is introduced, all or
67 * portions of this visitor may be deprecated.
68 *
69 * @param <R> the return type of this visitor's methods. Use {@link
70 * Void} for visitors that do not need to return results.
71 * @param <P> the type of the additional parameter to this visitor's
72 * methods. Use {@code Void} for visitors that do not need an
73 * additional parameter.
74 *
75 * @see TypeKindVisitor6
76 * @see TypeKindVisitor7
77 * @see TypeKindVisitor8
78 * @since 9
79 */
80 @SupportedSourceVersion(RELEASE_13)
81 public class TypeKindVisitor9<R, P> extends TypeKindVisitor8<R, P> {
82 /**
83 * Constructor for concrete subclasses to call; uses {@code null}
84 * for the default value.
85 */
86 protected TypeKindVisitor9() {
87 super(null);
88 }
89
90 /**
91 * Constructor for concrete subclasses to call; uses the argument
92 * for the default value.
93 *
94 * @param defaultValue the value to assign to {@link #DEFAULT_VALUE}
95 */
96 protected TypeKindVisitor9(R defaultValue) {
97 super(defaultValue);
98 }
99
100 /**
101 * {@inheritDoc}
102 *
103 * @implSpec This implementation calls {@code defaultAction}.
104 *
105 * @param t {@inheritDoc}
106 * @param p {@inheritDoc}
107 * @return the result of {@code defaultAction}
108 *
109 * @since 10
110 */
111 @Override
112 public R visitNoTypeAsModule(NoType t, P p) {
113 return defaultAction(t, p);
114 }
115 }