1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/src/share/classes/com/sun/source/util/TreeScanner.java Sat Dec 01 00:00:00 2007 +0000
1.3 @@ -0,0 +1,381 @@
1.4 +/*
1.5 + * Copyright 2005-2006 Sun Microsystems, Inc. All Rights Reserved.
1.6 + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
1.7 + *
1.8 + * This code is free software; you can redistribute it and/or modify it
1.9 + * under the terms of the GNU General Public License version 2 only, as
1.10 + * published by the Free Software Foundation. Sun designates this
1.11 + * particular file as subject to the "Classpath" exception as provided
1.12 + * by Sun in the LICENSE file that accompanied this code.
1.13 + *
1.14 + * This code is distributed in the hope that it will be useful, but WITHOUT
1.15 + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
1.16 + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
1.17 + * version 2 for more details (a copy is included in the LICENSE file that
1.18 + * accompanied this code).
1.19 + *
1.20 + * You should have received a copy of the GNU General Public License version
1.21 + * 2 along with this work; if not, write to the Free Software Foundation,
1.22 + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
1.23 + *
1.24 + * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
1.25 + * CA 95054 USA or visit www.sun.com if you need additional information or
1.26 + * have any questions.
1.27 + */
1.28 +
1.29 +package com.sun.source.util;
1.30 +
1.31 +import com.sun.source.tree.*;
1.32 +
1.33 +/**
1.34 + * A TreeVisitor that visits all the child tree nodes.
1.35 + * To visit nodes of a particular type, just override the
1.36 + * corresponding visitXYZ method.
1.37 + * Inside your method, call super.visitXYZ to visit descendant
1.38 + * nodes.
1.39 + *
1.40 + * <p>The default implementation of the visitXYZ methods will determine
1.41 + * a result as follows:
1.42 + * <ul>
1.43 + * <li>If the node being visited has no children, the result will be null.
1.44 + * <li>If the node being visited has one child, the result will be the
1.45 + * result of calling {@code scan} on that child. The child may be a simple node
1.46 + * or itself a list of nodes.
1.47 + * <li> If the node being visited has more than one child, the result will
1.48 + * be determined by calling {@code scan} each child in turn, and then combining the
1.49 + * result of each scan after the first with the cumulative result
1.50 + * so far, as determined by the {@link #reduce} method. Each child may be either
1.51 + * a simple node of a list of nodes. The default behavior of the {@code reduce}
1.52 + * method is such that the result of the visitXYZ method will be the result of
1.53 + * the last child scanned.
1.54 + * </ul>
1.55 + *
1.56 + * <p>Here is an example to count the number of identifier nodes in a tree:
1.57 + * <pre>
1.58 + * class CountIdentifiers extends TreeScanner<Integer,Void> {
1.59 + * {@literal @}Override
1.60 + * public Integer visitIdentifier(IdentifierTree node, Void p) {
1.61 + * return 1;
1.62 + * }
1.63 + * {@literal @}Override
1.64 + * public Integer reduce(Integer r1, Integer r2) {
1.65 + * return (r1 == null ? 0 : r1) + (r2 == null ? 0 : r2);
1.66 + * }
1.67 + * }
1.68 + * </pre>
1.69 + *
1.70 + * @author Peter von der Ahé
1.71 + * @author Jonathan Gibbons
1.72 + * @since 1.6
1.73 + */
1.74 +public class TreeScanner<R,P> implements TreeVisitor<R,P> {
1.75 +
1.76 + /** Scan a single node.
1.77 + */
1.78 + public R scan(Tree node, P p) {
1.79 + return (node == null) ? null : node.accept(this, p);
1.80 + }
1.81 +
1.82 + private R scanAndReduce(Tree node, P p, R r) {
1.83 + return reduce(scan(node, p), r);
1.84 + }
1.85 +
1.86 + /** Scan a list of nodes.
1.87 + */
1.88 + public R scan(Iterable<? extends Tree> nodes, P p) {
1.89 + R r = null;
1.90 + if (nodes != null) {
1.91 + boolean first = true;
1.92 + for (Tree node : nodes) {
1.93 + r = (first ? scan(node, p) : scanAndReduce(node, p, r));
1.94 + first = false;
1.95 + }
1.96 + }
1.97 + return r;
1.98 + }
1.99 +
1.100 + private R scanAndReduce(Iterable<? extends Tree> nodes, P p, R r) {
1.101 + return reduce(scan(nodes, p), r);
1.102 + }
1.103 +
1.104 + /**
1.105 + * Reduces two results into a combined result.
1.106 + * The default implementation is to return the first parameter.
1.107 + * The general contract of the method is that it may take any action whatsoever.
1.108 + */
1.109 + public R reduce(R r1, R r2) {
1.110 + return r1;
1.111 + }
1.112 +
1.113 +
1.114 +/* ***************************************************************************
1.115 + * Visitor methods
1.116 + ****************************************************************************/
1.117 +
1.118 + public R visitCompilationUnit(CompilationUnitTree node, P p) {
1.119 + R r = scan(node.getPackageAnnotations(), p);
1.120 + r = scanAndReduce(node.getPackageName(), p, r);
1.121 + r = scanAndReduce(node.getImports(), p, r);
1.122 + r = scanAndReduce(node.getTypeDecls(), p, r);
1.123 + return r;
1.124 + }
1.125 +
1.126 + public R visitImport(ImportTree node, P p) {
1.127 + return scan(node.getQualifiedIdentifier(), p);
1.128 + }
1.129 +
1.130 + public R visitClass(ClassTree node, P p) {
1.131 + R r = scan(node.getModifiers(), p);
1.132 + r = scanAndReduce(node.getTypeParameters(), p, r);
1.133 + r = scanAndReduce(node.getExtendsClause(), p, r);
1.134 + r = scanAndReduce(node.getImplementsClause(), p, r);
1.135 + r = scanAndReduce(node.getMembers(), p, r);
1.136 + return r;
1.137 + }
1.138 +
1.139 + public R visitMethod(MethodTree node, P p) {
1.140 + R r = scan(node.getModifiers(), p);
1.141 + r = scanAndReduce(node.getReturnType(), p, r);
1.142 + r = scanAndReduce(node.getTypeParameters(), p, r);
1.143 + r = scanAndReduce(node.getParameters(), p, r);
1.144 + r = scanAndReduce(node.getThrows(), p, r);
1.145 + r = scanAndReduce(node.getBody(), p, r);
1.146 + return r;
1.147 + }
1.148 +
1.149 + public R visitVariable(VariableTree node, P p) {
1.150 + R r = scan(node.getModifiers(), p);
1.151 + r = scanAndReduce(node.getType(), p, r);
1.152 + r = scanAndReduce(node.getInitializer(), p, r);
1.153 + return r;
1.154 + }
1.155 +
1.156 + public R visitEmptyStatement(EmptyStatementTree node, P p) {
1.157 + return null;
1.158 + }
1.159 +
1.160 + public R visitBlock(BlockTree node, P p) {
1.161 + return scan(node.getStatements(), p);
1.162 + }
1.163 +
1.164 + public R visitDoWhileLoop(DoWhileLoopTree node, P p) {
1.165 + R r = scan(node.getStatement(), p);
1.166 + r = scanAndReduce(node.getCondition(), p, r);
1.167 + return r;
1.168 + }
1.169 +
1.170 + public R visitWhileLoop(WhileLoopTree node, P p) {
1.171 + R r = scan(node.getCondition(), p);
1.172 + r = scanAndReduce(node.getStatement(), p, r);
1.173 + return r;
1.174 + }
1.175 +
1.176 + public R visitForLoop(ForLoopTree node, P p) {
1.177 + R r = scan(node.getInitializer(), p);
1.178 + r = scanAndReduce(node.getCondition(), p, r);
1.179 + r = scanAndReduce(node.getUpdate(), p, r);
1.180 + r = scanAndReduce(node.getStatement(), p, r);
1.181 + return r;
1.182 + }
1.183 +
1.184 + public R visitEnhancedForLoop(EnhancedForLoopTree node, P p) {
1.185 + R r = scan(node.getVariable(), p);
1.186 + r = scanAndReduce(node.getExpression(), p, r);
1.187 + r = scanAndReduce(node.getStatement(), p, r);
1.188 + return r;
1.189 + }
1.190 +
1.191 + public R visitLabeledStatement(LabeledStatementTree node, P p) {
1.192 + return scan(node.getStatement(), p);
1.193 + }
1.194 +
1.195 + public R visitSwitch(SwitchTree node, P p) {
1.196 + R r = scan(node.getExpression(), p);
1.197 + r = scanAndReduce(node.getCases(), p, r);
1.198 + return r;
1.199 + }
1.200 +
1.201 + public R visitCase(CaseTree node, P p) {
1.202 + R r = scan(node.getExpression(), p);
1.203 + r = scanAndReduce(node.getStatements(), p, r);
1.204 + return r;
1.205 + }
1.206 +
1.207 + public R visitSynchronized(SynchronizedTree node, P p) {
1.208 + R r = scan(node.getExpression(), p);
1.209 + r = scanAndReduce(node.getBlock(), p, r);
1.210 + return r;
1.211 + }
1.212 +
1.213 + public R visitTry(TryTree node, P p) {
1.214 + R r = scan(node.getBlock(), p);
1.215 + r = scanAndReduce(node.getCatches(), p, r);
1.216 + r = scanAndReduce(node.getFinallyBlock(), p, r);
1.217 + return r;
1.218 + }
1.219 +
1.220 + public R visitCatch(CatchTree node, P p) {
1.221 + R r = scan(node.getParameter(), p);
1.222 + r = scanAndReduce(node.getBlock(), p, r);
1.223 + return r;
1.224 + }
1.225 +
1.226 + public R visitConditionalExpression(ConditionalExpressionTree node, P p) {
1.227 + R r = scan(node.getCondition(), p);
1.228 + r = scanAndReduce(node.getTrueExpression(), p, r);
1.229 + r = scanAndReduce(node.getFalseExpression(), p, r);
1.230 + return r;
1.231 + }
1.232 +
1.233 + public R visitIf(IfTree node, P p) {
1.234 + R r = scan(node.getCondition(), p);
1.235 + r = scanAndReduce(node.getThenStatement(), p, r);
1.236 + r = scanAndReduce(node.getElseStatement(), p, r);
1.237 + return r;
1.238 + }
1.239 +
1.240 + public R visitExpressionStatement(ExpressionStatementTree node, P p) {
1.241 + return scan(node.getExpression(), p);
1.242 + }
1.243 +
1.244 + public R visitBreak(BreakTree node, P p) {
1.245 + return null;
1.246 + }
1.247 +
1.248 + public R visitContinue(ContinueTree node, P p) {
1.249 + return null;
1.250 + }
1.251 +
1.252 + public R visitReturn(ReturnTree node, P p) {
1.253 + return scan(node.getExpression(), p);
1.254 + }
1.255 +
1.256 + public R visitThrow(ThrowTree node, P p) {
1.257 + return scan(node.getExpression(), p);
1.258 + }
1.259 +
1.260 + public R visitAssert(AssertTree node, P p) {
1.261 + R r = scan(node.getCondition(), p);
1.262 + r = scanAndReduce(node.getDetail(), p, r);
1.263 + return r;
1.264 + }
1.265 +
1.266 + public R visitMethodInvocation(MethodInvocationTree node, P p) {
1.267 + R r = scan(node.getTypeArguments(), p);
1.268 + r = scanAndReduce(node.getMethodSelect(), p, r);
1.269 + r = scanAndReduce(node.getArguments(), p, r);
1.270 + return r;
1.271 + }
1.272 +
1.273 + public R visitNewClass(NewClassTree node, P p) {
1.274 + R r = scan(node.getEnclosingExpression(), p);
1.275 + r = scanAndReduce(node.getIdentifier(), p, r);
1.276 + r = scanAndReduce(node.getTypeArguments(), p, r);
1.277 + r = scanAndReduce(node.getArguments(), p, r);
1.278 + r = scanAndReduce(node.getClassBody(), p, r);
1.279 + return r;
1.280 + }
1.281 +
1.282 + public R visitNewArray(NewArrayTree node, P p) {
1.283 + R r = scan(node.getType(), p);
1.284 + r = scanAndReduce(node.getDimensions(), p, r);
1.285 + r = scanAndReduce(node.getInitializers(), p, r);
1.286 + return r;
1.287 + }
1.288 +
1.289 + public R visitParenthesized(ParenthesizedTree node, P p) {
1.290 + return scan(node.getExpression(), p);
1.291 + }
1.292 +
1.293 + public R visitAssignment(AssignmentTree node, P p) {
1.294 + R r = scan(node.getVariable(), p);
1.295 + r = scanAndReduce(node.getExpression(), p, r);
1.296 + return r;
1.297 + }
1.298 +
1.299 + public R visitCompoundAssignment(CompoundAssignmentTree node, P p) {
1.300 + R r = scan(node.getVariable(), p);
1.301 + r = scanAndReduce(node.getExpression(), p, r);
1.302 + return r;
1.303 + }
1.304 +
1.305 + public R visitUnary(UnaryTree node, P p) {
1.306 + return scan(node.getExpression(), p);
1.307 + }
1.308 +
1.309 + public R visitBinary(BinaryTree node, P p) {
1.310 + R r = scan(node.getLeftOperand(), p);
1.311 + r = scanAndReduce(node.getRightOperand(), p, r);
1.312 + return r;
1.313 + }
1.314 +
1.315 + public R visitTypeCast(TypeCastTree node, P p) {
1.316 + R r = scan(node.getType(), p);
1.317 + r = scanAndReduce(node.getExpression(), p, r);
1.318 + return r;
1.319 + }
1.320 +
1.321 + public R visitInstanceOf(InstanceOfTree node, P p) {
1.322 + R r = scan(node.getExpression(), p);
1.323 + r = scanAndReduce(node.getType(), p, r);
1.324 + return r;
1.325 + }
1.326 +
1.327 + public R visitArrayAccess(ArrayAccessTree node, P p) {
1.328 + R r = scan(node.getExpression(), p);
1.329 + r = scanAndReduce(node.getIndex(), p, r);
1.330 + return r;
1.331 + }
1.332 +
1.333 + public R visitMemberSelect(MemberSelectTree node, P p) {
1.334 + return scan(node.getExpression(), p);
1.335 + }
1.336 +
1.337 + public R visitIdentifier(IdentifierTree node, P p) {
1.338 + return null;
1.339 + }
1.340 +
1.341 + public R visitLiteral(LiteralTree node, P p) {
1.342 + return null;
1.343 + }
1.344 +
1.345 + public R visitPrimitiveType(PrimitiveTypeTree node, P p) {
1.346 + return null;
1.347 + }
1.348 +
1.349 + public R visitArrayType(ArrayTypeTree node, P p) {
1.350 + return scan(node.getType(), p);
1.351 + }
1.352 +
1.353 + public R visitParameterizedType(ParameterizedTypeTree node, P p) {
1.354 + R r = scan(node.getType(), p);
1.355 + r = scanAndReduce(node.getTypeArguments(), p, r);
1.356 + return r;
1.357 + }
1.358 +
1.359 + public R visitTypeParameter(TypeParameterTree node, P p) {
1.360 + return scan(node.getBounds(), p);
1.361 + }
1.362 +
1.363 + public R visitWildcard(WildcardTree node, P p) {
1.364 + return scan(node.getBound(), p);
1.365 + }
1.366 +
1.367 + public R visitModifiers(ModifiersTree node, P p) {
1.368 + return scan(node.getAnnotations(), p);
1.369 + }
1.370 +
1.371 + public R visitAnnotation(AnnotationTree node, P p) {
1.372 + R r = scan(node.getAnnotationType(), p);
1.373 + r = scanAndReduce(node.getArguments(), p, r);
1.374 + return r;
1.375 + }
1.376 +
1.377 + public R visitOther(Tree node, P p) {
1.378 + return null;
1.379 + }
1.380 +
1.381 + public R visitErroneous(ErroneousTree node, P p) {
1.382 + return null;
1.383 + }
1.384 +}
