Mercurial > jdk8-mips64-public > langtools / file revision
src/share/classes/com/sun/source/util/TreeScanner.java@8cc5b440fdde
src/share/classes/com/sun/source/util/TreeScanner.java
Wed, 06 Apr 2011 19:30:57 -0700
- author
- darcy
- date
- Wed, 06 Apr 2011 19:30:57 -0700
- changeset 969
- 8cc5b440fdde
- parent 815
- d17f37522154
- child 1142
- c896d95e7469
- permissions
- -rw-r--r--
7033809: Rename "disjunctive" to "union" in javax.lang.model
Reviewed-by: mcimadamore, jjg
1 /*
2 * Copyright (c) 2005, 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 */
26 package com.sun.source.util;
28 import com.sun.source.tree.*;
30 /**
31 * A TreeVisitor that visits all the child tree nodes.
32 * To visit nodes of a particular type, just override the
33 * corresponding visitXYZ method.
34 * Inside your method, call super.visitXYZ to visit descendant
35 * nodes.
36 *
37 * <p>The default implementation of the visitXYZ methods will determine
38 * a result as follows:
39 * <ul>
40 * <li>If the node being visited has no children, the result will be null.
41 * <li>If the node being visited has one child, the result will be the
42 * result of calling {@code scan} on that child. The child may be a simple node
43 * or itself a list of nodes.
44 * <li> If the node being visited has more than one child, the result will
45 * be determined by calling {@code scan} each child in turn, and then combining the
46 * result of each scan after the first with the cumulative result
47 * so far, as determined by the {@link #reduce} method. Each child may be either
48 * a simple node of a list of nodes. The default behavior of the {@code reduce}
49 * method is such that the result of the visitXYZ method will be the result of
50 * the last child scanned.
51 * </ul>
52 *
53 * <p>Here is an example to count the number of identifier nodes in a tree:
54 * <pre>
55 * class CountIdentifiers extends TreeScanner<Integer,Void> {
56 * {@literal @}Override
57 * public Integer visitIdentifier(IdentifierTree node, Void p) {
58 * return 1;
59 * }
60 * {@literal @}Override
61 * public Integer reduce(Integer r1, Integer r2) {
62 * return (r1 == null ? 0 : r1) + (r2 == null ? 0 : r2);
63 * }
64 * }
65 * </pre>
66 *
67 * @author Peter von der Ahé
68 * @author Jonathan Gibbons
69 * @since 1.6
70 */
71 public class TreeScanner<R,P> implements TreeVisitor<R,P> {
73 /** Scan a single node.
74 */
75 public R scan(Tree node, P p) {
76 return (node == null) ? null : node.accept(this, p);
77 }
79 private R scanAndReduce(Tree node, P p, R r) {
80 return reduce(scan(node, p), r);
81 }
83 /** Scan a list of nodes.
84 */
85 public R scan(Iterable<? extends Tree> nodes, P p) {
86 R r = null;
87 if (nodes != null) {
88 boolean first = true;
89 for (Tree node : nodes) {
90 r = (first ? scan(node, p) : scanAndReduce(node, p, r));
91 first = false;
92 }
93 }
94 return r;
95 }
97 private R scanAndReduce(Iterable<? extends Tree> nodes, P p, R r) {
98 return reduce(scan(nodes, p), r);
99 }
101 /**
102 * Reduces two results into a combined result.
103 * The default implementation is to return the first parameter.
104 * The general contract of the method is that it may take any action whatsoever.
105 */
106 public R reduce(R r1, R r2) {
107 return r1;
108 }
111 /* ***************************************************************************
112 * Visitor methods
113 ****************************************************************************/
115 public R visitCompilationUnit(CompilationUnitTree node, P p) {
116 R r = scan(node.getPackageAnnotations(), p);
117 r = scanAndReduce(node.getPackageName(), p, r);
118 r = scanAndReduce(node.getImports(), p, r);
119 r = scanAndReduce(node.getTypeDecls(), p, r);
120 return r;
121 }
123 public R visitImport(ImportTree node, P p) {
124 return scan(node.getQualifiedIdentifier(), p);
125 }
127 public R visitClass(ClassTree node, P p) {
128 R r = scan(node.getModifiers(), p);
129 r = scanAndReduce(node.getTypeParameters(), p, r);
130 r = scanAndReduce(node.getExtendsClause(), p, r);
131 r = scanAndReduce(node.getImplementsClause(), p, r);
132 r = scanAndReduce(node.getMembers(), p, r);
133 return r;
134 }
136 public R visitMethod(MethodTree node, P p) {
137 R r = scan(node.getModifiers(), p);
138 r = scanAndReduce(node.getReturnType(), p, r);
139 r = scanAndReduce(node.getTypeParameters(), p, r);
140 r = scanAndReduce(node.getParameters(), p, r);
141 r = scanAndReduce(node.getThrows(), p, r);
142 r = scanAndReduce(node.getBody(), p, r);
143 r = scanAndReduce(node.getDefaultValue(), p, r);
144 return r;
145 }
147 public R visitVariable(VariableTree node, P p) {
148 R r = scan(node.getModifiers(), p);
149 r = scanAndReduce(node.getType(), p, r);
150 r = scanAndReduce(node.getInitializer(), p, r);
151 return r;
152 }
154 public R visitEmptyStatement(EmptyStatementTree node, P p) {
155 return null;
156 }
158 public R visitBlock(BlockTree node, P p) {
159 return scan(node.getStatements(), p);
160 }
162 public R visitDoWhileLoop(DoWhileLoopTree node, P p) {
163 R r = scan(node.getStatement(), p);
164 r = scanAndReduce(node.getCondition(), p, r);
165 return r;
166 }
168 public R visitWhileLoop(WhileLoopTree node, P p) {
169 R r = scan(node.getCondition(), p);
170 r = scanAndReduce(node.getStatement(), p, r);
171 return r;
172 }
174 public R visitForLoop(ForLoopTree node, P p) {
175 R r = scan(node.getInitializer(), p);
176 r = scanAndReduce(node.getCondition(), p, r);
177 r = scanAndReduce(node.getUpdate(), p, r);
178 r = scanAndReduce(node.getStatement(), p, r);
179 return r;
180 }
182 public R visitEnhancedForLoop(EnhancedForLoopTree node, P p) {
183 R r = scan(node.getVariable(), p);
184 r = scanAndReduce(node.getExpression(), p, r);
185 r = scanAndReduce(node.getStatement(), p, r);
186 return r;
187 }
189 public R visitLabeledStatement(LabeledStatementTree node, P p) {
190 return scan(node.getStatement(), p);
191 }
193 public R visitSwitch(SwitchTree node, P p) {
194 R r = scan(node.getExpression(), p);
195 r = scanAndReduce(node.getCases(), p, r);
196 return r;
197 }
199 public R visitCase(CaseTree node, P p) {
200 R r = scan(node.getExpression(), p);
201 r = scanAndReduce(node.getStatements(), p, r);
202 return r;
203 }
205 public R visitSynchronized(SynchronizedTree node, P p) {
206 R r = scan(node.getExpression(), p);
207 r = scanAndReduce(node.getBlock(), p, r);
208 return r;
209 }
211 public R visitTry(TryTree node, P p) {
212 R r = scan(node.getResources(), p);
213 r = scanAndReduce(node.getBlock(), p, r);
214 r = scanAndReduce(node.getCatches(), p, r);
215 r = scanAndReduce(node.getFinallyBlock(), p, r);
216 return r;
217 }
219 public R visitCatch(CatchTree node, P p) {
220 R r = scan(node.getParameter(), p);
221 r = scanAndReduce(node.getBlock(), p, r);
222 return r;
223 }
225 public R visitConditionalExpression(ConditionalExpressionTree node, P p) {
226 R r = scan(node.getCondition(), p);
227 r = scanAndReduce(node.getTrueExpression(), p, r);
228 r = scanAndReduce(node.getFalseExpression(), p, r);
229 return r;
230 }
232 public R visitIf(IfTree node, P p) {
233 R r = scan(node.getCondition(), p);
234 r = scanAndReduce(node.getThenStatement(), p, r);
235 r = scanAndReduce(node.getElseStatement(), p, r);
236 return r;
237 }
239 public R visitExpressionStatement(ExpressionStatementTree node, P p) {
240 return scan(node.getExpression(), p);
241 }
243 public R visitBreak(BreakTree node, P p) {
244 return null;
245 }
247 public R visitContinue(ContinueTree node, P p) {
248 return null;
249 }
251 public R visitReturn(ReturnTree node, P p) {
252 return scan(node.getExpression(), p);
253 }
255 public R visitThrow(ThrowTree node, P p) {
256 return scan(node.getExpression(), p);
257 }
259 public R visitAssert(AssertTree node, P p) {
260 R r = scan(node.getCondition(), p);
261 r = scanAndReduce(node.getDetail(), p, r);
262 return r;
263 }
265 public R visitMethodInvocation(MethodInvocationTree node, P p) {
266 R r = scan(node.getTypeArguments(), p);
267 r = scanAndReduce(node.getMethodSelect(), p, r);
268 r = scanAndReduce(node.getArguments(), p, r);
269 return r;
270 }
272 public R visitNewClass(NewClassTree node, P p) {
273 R r = scan(node.getEnclosingExpression(), p);
274 r = scanAndReduce(node.getIdentifier(), p, r);
275 r = scanAndReduce(node.getTypeArguments(), p, r);
276 r = scanAndReduce(node.getArguments(), p, r);
277 r = scanAndReduce(node.getClassBody(), p, r);
278 return r;
279 }
281 public R visitNewArray(NewArrayTree node, P p) {
282 R r = scan(node.getType(), p);
283 r = scanAndReduce(node.getDimensions(), p, r);
284 r = scanAndReduce(node.getInitializers(), p, r);
285 return r;
286 }
288 public R visitParenthesized(ParenthesizedTree node, P p) {
289 return scan(node.getExpression(), p);
290 }
292 public R visitAssignment(AssignmentTree node, P p) {
293 R r = scan(node.getVariable(), p);
294 r = scanAndReduce(node.getExpression(), p, r);
295 return r;
296 }
298 public R visitCompoundAssignment(CompoundAssignmentTree node, P p) {
299 R r = scan(node.getVariable(), p);
300 r = scanAndReduce(node.getExpression(), p, r);
301 return r;
302 }
304 public R visitUnary(UnaryTree node, P p) {
305 return scan(node.getExpression(), p);
306 }
308 public R visitBinary(BinaryTree node, P p) {
309 R r = scan(node.getLeftOperand(), p);
310 r = scanAndReduce(node.getRightOperand(), p, r);
311 return r;
312 }
314 public R visitTypeCast(TypeCastTree node, P p) {
315 R r = scan(node.getType(), p);
316 r = scanAndReduce(node.getExpression(), p, r);
317 return r;
318 }
320 public R visitInstanceOf(InstanceOfTree node, P p) {
321 R r = scan(node.getExpression(), p);
322 r = scanAndReduce(node.getType(), p, r);
323 return r;
324 }
326 public R visitArrayAccess(ArrayAccessTree node, P p) {
327 R r = scan(node.getExpression(), p);
328 r = scanAndReduce(node.getIndex(), p, r);
329 return r;
330 }
332 public R visitMemberSelect(MemberSelectTree node, P p) {
333 return scan(node.getExpression(), p);
334 }
336 public R visitIdentifier(IdentifierTree node, P p) {
337 return null;
338 }
340 public R visitLiteral(LiteralTree node, P p) {
341 return null;
342 }
344 public R visitPrimitiveType(PrimitiveTypeTree node, P p) {
345 return null;
346 }
348 public R visitArrayType(ArrayTypeTree node, P p) {
349 return scan(node.getType(), p);
350 }
352 public R visitParameterizedType(ParameterizedTypeTree node, P p) {
353 R r = scan(node.getType(), p);
354 r = scanAndReduce(node.getTypeArguments(), p, r);
355 return r;
356 }
358 public R visitUnionType(UnionTypeTree node, P p) {
359 return scan(node.getTypeAlternatives(), p);
360 }
362 public R visitTypeParameter(TypeParameterTree node, P p) {
363 R r = scan(node.getBounds(), p);
364 return r;
365 }
367 public R visitWildcard(WildcardTree node, P p) {
368 return scan(node.getBound(), p);
369 }
371 public R visitModifiers(ModifiersTree node, P p) {
372 return scan(node.getAnnotations(), p);
373 }
375 public R visitAnnotation(AnnotationTree node, P p) {
376 R r = scan(node.getAnnotationType(), p);
377 r = scanAndReduce(node.getArguments(), p, r);
378 return r;
379 }
381 public R visitOther(Tree node, P p) {
382 return null;
383 }
385 public R visitErroneous(ErroneousTree node, P p) {
386 return null;
387 }
388 }
