1 /*
2 * Copyright (c) 2005, 2014, 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.type.*;
30
31 import static javax.lang.model.SourceVersion.*;
32
33 /**
34 * A skeletal visitor of types with default behavior appropriate for
35 * the {@link javax.lang.model.SourceVersion#RELEASE_6 RELEASE_6}
36 * source version.
37 *
38 * <p> <b>WARNING:</b> The {@code TypeVisitor} interface implemented
39 * by this class may have methods added to it in the future to
40 * accommodate new, currently unknown, language structures added to
41 * future versions of the Java™ programming language.
42 * Therefore, methods whose names begin with {@code "visit"} may be
43 * added to this class in the future; to avoid incompatibilities,
44 * classes which extend this class should not declare any instance
45 * methods with names beginning with {@code "visit"}.
46 *
47 * <p>When such a new visit method is added, the default
48 * implementation in this class will be to call the {@link
49 * #visitUnknown visitUnknown} method. A new abstract type visitor
50 * class will also be introduced to correspond to the new language
51 * level; this visitor will have different default behavior for the
52 * visit method in question. When the new visitor is introduced, all
53 * or portions of this visitor may be deprecated.
54 *
55 * <p>Note that adding a default implementation of a new visit method
56 * in a visitor class will occur instead of adding a <em>default
57 * method</em> directly in the visitor interface since a Java SE 8
58 * language feature cannot be used to this version of the API since
59 * this version is required to be runnable on Java SE 7
60 * implementations. Future versions of the API that are only required
61 * to run on Java SE 8 and later may take advantage of default methods
62 * in this situation.
63 *
64 * @param <R> the return type of this visitor's methods. Use {@link
65 * Void} for visitors that do not need to return results.
66 * @param <P> the type of the additional parameter to this visitor's
67 * methods. Use {@code Void} for visitors that do not need an
68 * additional parameter.
69 *
70 * @author Joseph D. Darcy
71 * @author Scott Seligman
72 * @author Peter von der Ahé
73 *
74 * @see AbstractTypeVisitor7
75 * @see AbstractTypeVisitor8
76 * @see AbstractTypeVisitor9
77 * @since 1.6
78 * @deprecated Release 6 is obsolete; update to a visitor for a newer
79 * release level.
80 */
81 @Deprecated
82 @SupportedSourceVersion(RELEASE_6)
83 public abstract class AbstractTypeVisitor6<R, P> implements TypeVisitor<R, P> {
84 /**
85 * Constructor for concrete subclasses to call.
86 */
87 protected AbstractTypeVisitor6() {}
88
89 /**
90 * Visits any type mirror as if by passing itself to that type
91 * mirror's {@link TypeMirror#accept accept} method. The
92 * invocation {@code v.visit(t, p)} is equivalent to {@code
93 * t.accept(v, p)}.
94 *
95 * @param t the type to visit
96 * @param p a visitor-specified parameter
97 * @return a visitor-specified result
98 */
99 public final R visit(TypeMirror t, P p) {
100 return t.accept(this, p);
101 }
102
103 /**
104 * Visits any type mirror as if by passing itself to that type
105 * mirror's {@link TypeMirror#accept accept} method and passing
106 * {@code null} for the additional parameter. The invocation
107 * {@code v.visit(t)} is equivalent to {@code t.accept(v, null)}.
108 *
109 * @param t the type to visit
110 * @return a visitor-specified result
111 */
112 public final R visit(TypeMirror t) {
113 return t.accept(this, null);
114 }
115
116 /**
117 * {@inheritDoc}
118 *
119 * @implSpec Visits a {@code UnionType} element by calling {@code
120 * visitUnknown}.
121 *
122 * @param t {@inheritDoc}
123 * @param p {@inheritDoc}
124 * @return the result of {@code visitUnknown}
125 *
126 * @since 1.7
127 */
128 public R visitUnion(UnionType t, P p) {
129 return visitUnknown(t, p);
130 }
131
132 /**
133 * {@inheritDoc}
134 *
135 * @implSpec Visits an {@code IntersectionType} element by calling {@code
136 * visitUnknown}.
137 *
138 * @param t {@inheritDoc}
139 * @param p {@inheritDoc}
140 * @return the result of {@code visitUnknown}
141 *
142 * @since 1.8
143 */
144 @Override
145 public R visitIntersection(IntersectionType t, P p) {
146 return visitUnknown(t, p);
147 }
148
149 /**
150 * {@inheritDoc}
151 *
152 * @implSpec The default implementation of this method in {@code
153 * AbstractTypeVisitor6} will always throw {@code
154 * UnknownTypeException}. This behavior is not required of a
155 * subclass.
156 *
157 * @param t {@inheritDoc}
158 * @param p {@inheritDoc}
159 * @return a visitor-specified result
160 * @throws UnknownTypeException
161 * a visitor implementation may optionally throw this exception
162 */
163 @Override
164 public R visitUnknown(TypeMirror t, P p) {
165 throw new UnknownTypeException(t, p);
166 }
167 }