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} <tt><i>XYZ</i></tt> that may have more than one
38 * kind, the <tt>visit<i>XYZ</i></tt> methods in this class delegate
39 * to the <tt>visit<i>XYZKind</i></tt> method corresponding to the
40 * first argument's kind. The <tt>visit<i>XYZKind</i></tt> 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 */
95 protected TypeKindVisitor6() {
96 super(null);
97 }
98
99
100 /**
101 * Constructor for concrete subclasses to call; uses the argument
102 * for the default value.
103 *
104 * @param defaultValue the value to assign to {@link #DEFAULT_VALUE}
105 */
106 protected TypeKindVisitor6(R defaultValue) {
107 super(defaultValue);
108 }
109
110 /**
111 * Visits a primitive type, dispatching to the visit method for
112 * the specific {@linkplain TypeKind kind} of primitive type:
113 * {@code BOOLEAN}, {@code BYTE}, etc.
114 *
115 * @param t {@inheritDoc}
116 * @param p {@inheritDoc}
117 * @return the result of the kind-specific visit method
118 */
119 @Override
120 public R visitPrimitive(PrimitiveType t, P p) {
121 TypeKind k = t.getKind();
122 switch (k) {
123 case BOOLEAN:
124 return visitPrimitiveAsBoolean(t, p);
125
126 case BYTE:
127 return visitPrimitiveAsByte(t, p);
128
129 case SHORT:
130 return visitPrimitiveAsShort(t, p);
131
132 case INT:
133 return visitPrimitiveAsInt(t, p);
134
135 case LONG:
136 return visitPrimitiveAsLong(t, p);
137
138 case CHAR:
139 return visitPrimitiveAsChar(t, p);
140
141 case FLOAT:
142 return visitPrimitiveAsFloat(t, p);
143
144 case DOUBLE:
145 return visitPrimitiveAsDouble(t, p);
146
147 default:
148 throw new AssertionError("Bad kind " + k + " for PrimitiveType" + t);
149 }
150 }
151
152 /**
153 * Visits a {@code BOOLEAN} primitive type by calling
154 * {@code defaultAction}.
155 *
156 * @param t the type to visit
157 * @param p a visitor-specified parameter
158 * @return the result of {@code defaultAction}
159 */
160 public R visitPrimitiveAsBoolean(PrimitiveType t, P p) {
161 return defaultAction(t, p);
162 }
163
164 /**
165 * Visits a {@code BYTE} primitive type by calling
166 * {@code defaultAction}.
167 *
168 * @param t the type to visit
169 * @param p a visitor-specified parameter
170 * @return the result of {@code defaultAction}
171 */
172 public R visitPrimitiveAsByte(PrimitiveType t, P p) {
173 return defaultAction(t, p);
174 }
175
176 /**
177 * Visits a {@code SHORT} primitive type by calling
178 * {@code defaultAction}.
179 *
180 * @param t the type to visit
181 * @param p a visitor-specified parameter
182 * @return the result of {@code defaultAction}
183 */
184 public R visitPrimitiveAsShort(PrimitiveType t, P p) {
185 return defaultAction(t, p);
186 }
187
188 /**
189 * Visits an {@code INT} primitive type by calling
190 * {@code defaultAction}.
191 *
192 * @param t the type to visit
193 * @param p a visitor-specified parameter
194 * @return the result of {@code defaultAction}
195 */
196 public R visitPrimitiveAsInt(PrimitiveType t, P p) {
197 return defaultAction(t, p);
198 }
199
200 /**
201 * Visits a {@code LONG} primitive type by calling
202 * {@code defaultAction}.
203 *
204 * @param t the type to visit
205 * @param p a visitor-specified parameter
206 * @return the result of {@code defaultAction}
207 */
208 public R visitPrimitiveAsLong(PrimitiveType t, P p) {
209 return defaultAction(t, p);
210 }
211
212 /**
213 * Visits a {@code CHAR} primitive type by calling
214 * {@code defaultAction}.
215 *
216 * @param t the type to visit
217 * @param p a visitor-specified parameter
218 * @return the result of {@code defaultAction}
219 */
220 public R visitPrimitiveAsChar(PrimitiveType t, P p) {
221 return defaultAction(t, p);
222 }
223
224 /**
225 * Visits a {@code FLOAT} primitive type by calling
226 * {@code defaultAction}.
227 *
228 * @param t the type to visit
229 * @param p a visitor-specified parameter
230 * @return the result of {@code defaultAction}
231 */
232 public R visitPrimitiveAsFloat(PrimitiveType t, P p) {
233 return defaultAction(t, p);
234 }
235
236 /**
237 * Visits a {@code DOUBLE} primitive type by calling
238 * {@code defaultAction}.
239 *
240 * @param t the type to visit
241 * @param p a visitor-specified parameter
242 * @return the result of {@code defaultAction}
243 */
244 public R visitPrimitiveAsDouble(PrimitiveType t, P p) {
245 return defaultAction(t, p);
246 }
247
248 /**
249 * Visits a {@link NoType} instance, dispatching to the visit method for
250 * the specific {@linkplain TypeKind kind} of pseudo-type:
251 * {@code VOID}, {@code PACKAGE}, or {@code NONE}.
252 *
253 * @param t {@inheritDoc}
254 * @param p {@inheritDoc}
255 * @return the result of the kind-specific visit method
256 */
257 @Override
258 public R visitNoType(NoType t, P p) {
259 TypeKind k = t.getKind();
260 switch (k) {
261 case VOID:
262 return visitNoTypeAsVoid(t, p);
263
264 case PACKAGE:
265 return visitNoTypeAsPackage(t, p);
266
267 case NONE:
268 return visitNoTypeAsNone(t, p);
269
270 default:
271 throw new AssertionError("Bad kind " + k + " for NoType" + t);
272 }
273 }
274
275 /**
276 * Visits a {@link TypeKind#VOID VOID} pseudo-type by calling
277 * {@code defaultAction}.
278 *
279 * @param t the type to visit
280 * @param p a visitor-specified parameter
281 * @return the result of {@code defaultAction}
282 */
283 public R visitNoTypeAsVoid(NoType t, P p) {
284 return defaultAction(t, p);
285 }
286
287 /**
288 * Visits a {@link TypeKind#PACKAGE PACKAGE} pseudo-type by calling
289 * {@code defaultAction}.
290 *
291 * @param t the type to visit
292 * @param p a visitor-specified parameter
293 * @return the result of {@code defaultAction}
294 */
295 public R visitNoTypeAsPackage(NoType t, P p) {
296 return defaultAction(t, p);
297 }
298
299 /**
300 * Visits a {@link TypeKind#NONE NONE} pseudo-type by calling
301 * {@code defaultAction}.
302 *
303 * @param t the type to visit
304 * @param p a visitor-specified parameter
305 * @return the result of {@code defaultAction}
306 */
307 public R visitNoTypeAsNone(NoType t, P p) {
308 return defaultAction(t, p);
309 }
310 }