1 /*
2 * Copyright (c) 2011, 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.type.*;
29 import javax.annotation.processing.SupportedSourceVersion;
30 import static javax.lang.model.element.ElementKind.*;
31 import static javax.lang.model.SourceVersion.*;
32 import javax.lang.model.SourceVersion;
33
34 /**
35 * A visitor of types based on their {@linkplain TypeKind kind} with
36 * default behavior appropriate for the {@link SourceVersion#RELEASE_8
37 * RELEASE_8} source version. For {@linkplain
38 * TypeMirror types} <tt><i>XYZ</i></tt> that may have more than one
39 * kind, the <tt>visit<i>XYZ</i></tt> methods in this class delegate
40 * to the <tt>visit<i>XYZKind</i></tt> method corresponding to the
41 * first argument's kind. The <tt>visit<i>XYZKind</i></tt> methods
42 * call {@link #defaultAction defaultAction}, passing their arguments
43 * to {@code defaultAction}'s corresponding parameters.
44 *
45 * <p> Methods in this class may be overridden subject to their
46 * general contract. Note that annotating methods in concrete
47 * subclasses with {@link java.lang.Override @Override} will help
48 * ensure that methods are overridden as intended.
49 *
50 * <p> <b>WARNING:</b> The {@code TypeVisitor} interface implemented
51 * by this class may have methods added to it in the future to
52 * accommodate new, currently unknown, language structures added to
53 * future versions of the Java™ programming language.
54 * Therefore, methods whose names begin with {@code "visit"} may be
55 * added to this class in the future; to avoid incompatibilities,
56 * classes which extend this class should not declare any instance
57 * methods with names beginning with {@code "visit"}.
58 *
59 * <p>When such a new visit method is added, the default
60 * implementation in this class will be to call the {@link
61 * #visitUnknown visitUnknown} method. A new type kind visitor class
62 * will also be introduced to correspond to the new language level;
63 * this visitor will have different default behavior for the visit
64 * method in question. When the new visitor is introduced, all or
65 * portions of this visitor may be deprecated.
66 *
67 * @param <R> the return type of this visitor's methods. Use {@link
68 * Void} for visitors that do not need to return results.
69 * @param <P> the type of the additional parameter to this visitor's
70 * methods. Use {@code Void} for visitors that do not need an
71 * additional parameter.
72 *
73 * @see TypeKindVisitor6
74 * @see TypeKindVisitor7
75 * @since 1.8
76 */
77 @SupportedSourceVersion(RELEASE_8)
78 public class TypeKindVisitor8<R, P> extends TypeKindVisitor7<R, P> {
79 /**
80 * Constructor for concrete subclasses to call; uses {@code null}
81 * for the default value.
82 */
83 protected TypeKindVisitor8() {
84 super(null);
85 }
86
87 /**
88 * Constructor for concrete subclasses to call; uses the argument
89 * for the default value.
90 *
91 * @param defaultValue the value to assign to {@link #DEFAULT_VALUE}
92 */
93 protected TypeKindVisitor8(R defaultValue) {
94 super(defaultValue);
95 }
96 }