1 /*
2 * Copyright (c) 2005, 2013, 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 the {@link SourceVersion#RELEASE_6
36 * RELEASE_6} source version. For {@linkplain
37 * TypeMirror types} <code><i>XYZ</i></code> that may have more than one
38 * kind, the <code>visit<i>XYZ</i></code> methods in this class delegate
39 * to the <code>visit<i>XYZKind</i></code> method corresponding to the
40 * first argument's kind. The <code>visit<i>XYZKind</i></code> methods
41 * call {@link #defaultAction defaultAction}, passing their arguments
42 * to {@code defaultAction}'s corresponding parameters.
43 *
44 * <p> Methods in this class may be overridden subject to their
45 * general contract. Note that annotating methods in concrete
46 * subclasses with {@link java.lang.Override @Override} will help
47 * ensure that methods are overridden as intended.
48 *
49 * <p> <b>WARNING:</b> The {@code TypeVisitor} interface implemented
50 * by this class may have methods added to it in the future to
51 * accommodate new, currently unknown, language structures added to
52 * future versions of the Java™ programming language.
53 * Therefore, methods whose names begin with {@code "visit"} may be
54 * added to this class in the future; to avoid incompatibilities,
55 * classes which extend this class should not declare any instance
56 * methods with names beginning with {@code "visit"}.
57 *
58 * <p>When such a new visit method is added, the default
59 * implementation in this class will be to call the {@link
60 * #visitUnknown visitUnknown} method. A new type kind visitor class
61 * will also be introduced to correspond to the new language level;
62 * this visitor will have different default behavior for the visit
63 * method in question. When the new visitor is introduced, all or
64 * portions of this visitor may be deprecated.
65 *
66 * <p>Note that adding a default implementation of a new visit method
67 * in a visitor class will occur instead of adding a <em>default
68 * method</em> directly in the visitor interface since a Java SE 8
69 * language feature cannot be used to this version of the API since
70 * this version is required to be runnable on Java SE 7
71 * implementations. Future versions of the API that are only required
72 * to run on Java SE 8 and later may take advantage of default methods
73 * in this situation.
74 *
75 * @param <R> the return type of this visitor's methods. Use {@link
76 * Void} for visitors that do not need to return results.
77 * @param <P> the type of the additional parameter to this visitor's
78 * methods. Use {@code Void} for visitors that do not need an
79 * additional parameter.
80 *
81 * @author Joseph D. Darcy
82 * @author Scott Seligman
83 * @author Peter von der Ahé
84 *
85 * @see TypeKindVisitor7
86 * @see TypeKindVisitor8
87 * @since 1.6
88 */
89 @SupportedSourceVersion(RELEASE_6)
90 public class TypeKindVisitor6<R, P> extends SimpleTypeVisitor6<R, P> {
91 /**
92 * Constructor for concrete subclasses to call; uses {@code null}
93 * for the default value.
94 * @deprecated Release 6 is obsolete; update to a visitor for a newer
95 * release level.
96 */
97 @Deprecated
98 protected TypeKindVisitor6() {
99 super(null);
100 }
101
102
103 /**
104 * Constructor for concrete subclasses to call; uses the argument
105 * for the default value.
106 *
107 * @param defaultValue the value to assign to {@link #DEFAULT_VALUE}
108 * @deprecated Release 6 is obsolete; update to a visitor for a newer
109 * release level.
110 */
111 @Deprecated
112 protected TypeKindVisitor6(R defaultValue) {
113 super(defaultValue);
114 }
115
116 /**
117 * Visits a primitive type, dispatching to the visit method for
118 * the specific {@linkplain TypeKind kind} of primitive type:
119 * {@code BOOLEAN}, {@code BYTE}, etc.
120 *
121 * @param t {@inheritDoc}
122 * @param p {@inheritDoc}
123 * @return the result of the kind-specific visit method
124 */
125 @Override
126 public R visitPrimitive(PrimitiveType t, P p) {
127 TypeKind k = t.getKind();
128 switch (k) {
129 case BOOLEAN:
130 return visitPrimitiveAsBoolean(t, p);
131
132 case BYTE:
133 return visitPrimitiveAsByte(t, p);
134
135 case SHORT:
136 return visitPrimitiveAsShort(t, p);
137
138 case INT:
139 return visitPrimitiveAsInt(t, p);
140
141 case LONG:
142 return visitPrimitiveAsLong(t, p);
143
144 case CHAR:
145 return visitPrimitiveAsChar(t, p);
146
147 case FLOAT:
148 return visitPrimitiveAsFloat(t, p);
149
150 case DOUBLE:
151 return visitPrimitiveAsDouble(t, p);
152
153 default:
154 throw new AssertionError("Bad kind " + k + " for PrimitiveType" + t);
155 }
156 }
157
158 /**
159 * Visits a {@code BOOLEAN} primitive type by calling
160 * {@code defaultAction}.
161 *
162 * @param t the type to visit
163 * @param p a visitor-specified parameter
164 * @return the result of {@code defaultAction}
165 */
166 public R visitPrimitiveAsBoolean(PrimitiveType t, P p) {
167 return defaultAction(t, p);
168 }
169
170 /**
171 * Visits a {@code BYTE} primitive type by calling
172 * {@code defaultAction}.
173 *
174 * @param t the type to visit
175 * @param p a visitor-specified parameter
176 * @return the result of {@code defaultAction}
177 */
178 public R visitPrimitiveAsByte(PrimitiveType t, P p) {
179 return defaultAction(t, p);
180 }
181
182 /**
183 * Visits a {@code SHORT} primitive type by calling
184 * {@code defaultAction}.
185 *
186 * @param t the type to visit
187 * @param p a visitor-specified parameter
188 * @return the result of {@code defaultAction}
189 */
190 public R visitPrimitiveAsShort(PrimitiveType t, P p) {
191 return defaultAction(t, p);
192 }
193
194 /**
195 * Visits an {@code INT} primitive type by calling
196 * {@code defaultAction}.
197 *
198 * @param t the type to visit
199 * @param p a visitor-specified parameter
200 * @return the result of {@code defaultAction}
201 */
202 public R visitPrimitiveAsInt(PrimitiveType t, P p) {
203 return defaultAction(t, p);
204 }
205
206 /**
207 * Visits a {@code LONG} primitive type by calling
208 * {@code defaultAction}.
209 *
210 * @param t the type to visit
211 * @param p a visitor-specified parameter
212 * @return the result of {@code defaultAction}
213 */
214 public R visitPrimitiveAsLong(PrimitiveType t, P p) {
215 return defaultAction(t, p);
216 }
217
218 /**
219 * Visits a {@code CHAR} primitive type by calling
220 * {@code defaultAction}.
221 *
222 * @param t the type to visit
223 * @param p a visitor-specified parameter
224 * @return the result of {@code defaultAction}
225 */
226 public R visitPrimitiveAsChar(PrimitiveType t, P p) {
227 return defaultAction(t, p);
228 }
229
230 /**
231 * Visits a {@code FLOAT} primitive type by calling
232 * {@code defaultAction}.
233 *
234 * @param t the type to visit
235 * @param p a visitor-specified parameter
236 * @return the result of {@code defaultAction}
237 */
238 public R visitPrimitiveAsFloat(PrimitiveType t, P p) {
239 return defaultAction(t, p);
240 }
241
242 /**
243 * Visits a {@code DOUBLE} primitive type by calling
244 * {@code defaultAction}.
245 *
246 * @param t the type to visit
247 * @param p a visitor-specified parameter
248 * @return the result of {@code defaultAction}
249 */
250 public R visitPrimitiveAsDouble(PrimitiveType t, P p) {
251 return defaultAction(t, p);
252 }
253
254 /**
255 * Visits a {@link NoType} instance, dispatching to the visit method for
256 * the specific {@linkplain TypeKind kind} of pseudo-type:
257 * {@code VOID}, {@code PACKAGE}, or {@code NONE}.
258 *
259 * @param t {@inheritDoc}
260 * @param p {@inheritDoc}
261 * @return the result of the kind-specific visit method
262 */
263 @Override
264 public R visitNoType(NoType t, P p) {
265 TypeKind k = t.getKind();
266 switch (k) {
267 case VOID:
268 return visitNoTypeAsVoid(t, p);
269
270 case PACKAGE:
271 return visitNoTypeAsPackage(t, p);
272
273 case NONE:
274 return visitNoTypeAsNone(t, p);
275
276 default:
277 throw new AssertionError("Bad kind " + k + " for NoType" + t);
278 }
279 }
280
281 /**
282 * Visits a {@link TypeKind#VOID VOID} pseudo-type by calling
283 * {@code defaultAction}.
284 *
285 * @param t the type to visit
286 * @param p a visitor-specified parameter
287 * @return the result of {@code defaultAction}
288 */
289 public R visitNoTypeAsVoid(NoType t, P p) {
290 return defaultAction(t, p);
291 }
292
293 /**
294 * Visits a {@link TypeKind#PACKAGE PACKAGE} pseudo-type by calling
295 * {@code defaultAction}.
296 *
297 * @param t the type to visit
298 * @param p a visitor-specified parameter
299 * @return the result of {@code defaultAction}
300 */
301 public R visitNoTypeAsPackage(NoType t, P p) {
302 return defaultAction(t, p);
303 }
304
305 /**
306 * Visits a {@link TypeKind#NONE NONE} pseudo-type by calling
307 * {@code defaultAction}.
308 *
309 * @param t the type to visit
310 * @param p a visitor-specified parameter
311 * @return the result of {@code defaultAction}
312 */
313 public R visitNoTypeAsNone(NoType t, P p) {
314 return defaultAction(t, p);
315 }
316 }