1 /*
2 * Copyright (c) 2016, 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 jdk.nashorn.api.tree;
27
28 import java.util.List;
29
30 /**
31 * A simple implementation of the TreeVisitor for ECMAScript edition 6.
32 *
33 * <p>The visit methods corresponding to ES 6 language constructs walk the
34 * "components" of the given tree by calling accept method passing the
35 * current visitor and the additional parameter.
36 *
37 * <p>For constructs introduced in later versions, {@code visitUnknown}
38 * is called instead which throws {@link UnknownTreeException}.
39 *
40 * <p> Methods in this class may be overridden subject to their
41 * general contract. Note that annotating methods in concrete
42 * subclasses with {@link java.lang.Override @Override} will help
43 * ensure that methods are overridden as intended.
44 *
45 * @param <R> the return type of this visitor's methods. Use {@link
46 * Void} for visitors that do not need to return results.
47 * @param <P> the type of the additional parameter to this visitor's
48 * methods. Use {@code Void} for visitors that do not need an
49 * additional parameter.
50 */
51 public class SimpleTreeVisitorES6<R, P> extends SimpleTreeVisitorES5_1<R, P> {
52 @Override
53 public R visitCompilationUnit(final CompilationUnitTree node, final P r) {
54 final ModuleTree mod = node.getModule();
55 if (mod != null) {
56 mod.accept(this, r);
57 }
58 return super.visitCompilationUnit(node, r);
59 }
60
61 /**
62 * Visit Module tree.
63 *
64 * @param node node being visited
65 * @param p extra parameter passed to the visitor
66 * @return value from the visitor
67 */
68 @Override
69 public R visitModule(final ModuleTree node, final P p) {
70 node.getImportEntries().forEach(e -> visitImportEntry(e, p));
71 node.getLocalExportEntries().forEach(e -> visitExportEntry(e, p));
72 node.getIndirectExportEntries().forEach(e -> visitExportEntry(e, p));
73 node.getStarExportEntries().forEach(e -> visitExportEntry(e, p));
74 return null;
75 }
76
77 /**
78 * Visit Module ExportEntry tree.
79 *
80 * @param node node being visited
81 * @param p extra parameter passed to the visitor
82 * @return value from the visitor
83 */
84 @Override
85 public R visitExportEntry(final ExportEntryTree node, final P p) {
86 return null;
87 }
88
89 /**
90 * Visit Module ImportEntry tree.
91 *
92 * @param node node being visited
93 * @param p extra parameter passed to the visitor
94 * @return value from the visitor
95 */
96 @Override
97 public R visitImportEntry(final ImportEntryTree node, final P p) {
98 return null;
99 }
100
101 /**
102 * Visit class statement tree.
103 *
104 * @param node node being visited
105 * @param p extra parameter passed to the visitor
106 * @return value from the visitor
107 */
108 @Override
109 public R visitClassDeclaration(final ClassDeclarationTree node, final P p) {
110 node.getName().accept(this, p);
111 final ExpressionTree heritage = node.getClassHeritage();
112 if (heritage != null) {
113 heritage.accept(this, p);
114 }
115 final PropertyTree constructor = node.getConstructor();
116 if (constructor != null) {
117 constructor.accept(this, p);
118 }
119 final List<? extends PropertyTree> elements = node.getClassElements();
120 if (elements != null) {
121 for (final PropertyTree prop : elements) {
122 prop.accept(this, p);
123 }
124 }
125
126 return null;
127 }
128
129 /**
130 * Visit class expression tree.
131 *
132 * @param node node being visited
133 * @param p extra parameter passed to the visitor
134 * @return value from the visitor
135 */
136 @Override
137 public R visitClassExpression(final ClassExpressionTree node, final P p) {
138 node.getName().accept(this, p);
139 final ExpressionTree heritage = node.getClassHeritage();
140 if (heritage != null) {
141 heritage.accept(this, p);
142 }
143 final PropertyTree constructor = node.getConstructor();
144 if (constructor != null) {
145 constructor.accept(this, p);
146 }
147 final List<? extends PropertyTree> elements = node.getClassElements();
148 if (elements != null) {
149 for (final PropertyTree prop : elements) {
150 prop.accept(this, p);
151 }
152 }
153
154 return null;
155 }
156
157 /**
158 * Visit for..of statement tree.
159 *
160 * @param node node being visited
161 * @param p extra parameter passed to the visitor
162 * @return value from the visitor
163 */
164 @Override
165 public R visitForOfLoop(final ForOfLoopTree node, final P p) {
166 node.getVariable().accept(this, p);
167 node.getExpression().accept(this, p);
168 final StatementTree stat = node.getStatement();
169 if (stat != null) {
170 stat.accept(this, p);
171 }
172 return null;
173 }
174
175 /**
176 * Visit 'yield' expression tree.
177 *
178 * @param node node being visited
179 * @param p extra parameter passed to the visitor
180 * @return value from the visitor
181 */
182 @Override
183 public R visitYield(final YieldTree node, final P p) {
184 node.getExpression().accept(this, p);
185 return null;
186 }
187
188 /**
189 * Visit 'spread' expression tree.
190 *
191 * @param node node being visited
192 * @param p extra parameter passed to the visitor
193 * @return value from the visitor
194 */
195 @Override
196 public R visitSpread(final SpreadTree node, final P p) {
197 node.getExpression().accept(this, p);
198 return null;
199 }
200
201 /**
202 * Visit template literal tree.
203 *
204 * @param node node being visited
205 * @param p extra parameter passed to the visitor
206 * @return value from the visitor
207 */
208 @Override
209 public R visitTemplateLiteral(final TemplateLiteralTree node, final P p) {
210 final List<? extends ExpressionTree> expressions = node.getExpressions();
211 for (final ExpressionTree expr : expressions) {
212 expr.accept(this, p);
213 }
214 return null;
215 }
216
217 @Override
218 public R visitVariable(final VariableTree node, final P r) {
219 final ExpressionTree expr = node.getBinding();
220 if (expr != null) {
221 expr.accept(this, r);
222 }
223 super.visitVariable(node, r);
224 return null;
225 }
226 }