SimpleTreeVisitorES6.java revision 1739:4a6a1fd3d3dd 
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
26package jdk.nashorn.api.tree;
27
28import 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 */
51public 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(ModuleTree node, 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(ExportEntryTree node, 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(ImportEntryTree node, 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(ClassDeclarationTree node, 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 (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(ClassExpressionTree node, 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 (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(YieldTree node, 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(SpreadTree node, 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(TemplateLiteralTree node, P p) {
210        final List<? extends ExpressionTree> expressions = node.getExpressions();
211        for (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}
227