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1
16 package com.google.gwt.dev.js.ast;
17
18 import com.google.gwt.dev.jjs.InternalCompilerException;
19
20 import java.util.ArrayList  ;
21
22
25 public class JsModVisitor extends JsVisitor {
26
27 private interface ContextFactory {
28 JsContext create();
29 }
30
31 private class ContextPool extends ArrayList {
32
33 private ContextFactory factory;
34 private int pos = 0;
35
36 public ContextPool(ContextFactory factory) {
37 this.factory = factory;
38 }
39
40 public void release(JsContext ctx) {
41 if (get(--pos) != ctx) {
42 throw new InternalCompilerException(
43 "Tried to release the wrong context");
44 }
45 }
46
47 public JsContext take() {
48 if (pos == size()) {
49 add(factory.create());
50 }
51 return (JsContext) get(pos++);
52 }
53 }
54
55 private class ListContext implements JsContext {
56 private int index;
57 private JsCollection collection;
58 private boolean removed;
59 private boolean replaced;
60
61 public boolean canInsert() {
62 return true;
63 }
64
65 public boolean canRemove() {
66 return true;
67 }
68
69 public void insertAfter(JsNode node) {
70 checkRemoved();
71 collection.addNode(index + 1, node);
72 didChange = true;
73 }
74
75 public void insertBefore(JsNode node) {
76 checkRemoved();
77 collection.addNode(index++, node);
78 didChange = true;
79 }
80
81 public void removeMe() {
82 checkState();
83 collection.removeNode(index--);
84 didChange = removed = true;
85 }
86
87 public void replaceMe(JsNode node) {
88 checkState();
89 checkReplacement(collection.getNode(index), node);
90 collection.setNode(index, node);
91 didChange = replaced = true;
92 }
93
94 protected void doReplace(Class targetClass, JsNode x) {
95 checkState();
96 checkReplacement(collection.getNode(index), x);
97 collection.setNode(index, x);
98 didChange = replaced = true;
99 }
100
101 protected void traverse(JsCollection collection) {
102 this.collection = collection;
103 for (index = 0; index < collection.size(); ++index) {
104 removed = replaced = false;
105 doTraverse(collection.getNode(index), this);
106 }
107 }
108
109 private void checkRemoved() {
110 if (removed) {
111 throw new InternalCompilerException("Node was already removed");
112 }
113 }
114
115 private void checkState() {
116 checkRemoved();
117 if (replaced) {
118 throw new InternalCompilerException("Node was already replaced");
119 }
120 }
121 }
122
123 private class NodeContext implements JsContext {
124 private JsNode node;
125 private boolean replaced;
126
127 public boolean canInsert() {
128 return false;
129 }
130
131 public boolean canRemove() {
132 return false;
133 }
134
135 public void insertAfter(JsNode node) {
136 throw new UnsupportedOperationException ();
137 }
138
139 public void insertBefore(JsNode node) {
140 throw new UnsupportedOperationException ();
141 }
142
143 public void removeMe() {
144 throw new UnsupportedOperationException ();
145 }
146
147 public void replaceMe(JsNode node) {
148 if (replaced) {
149 throw new InternalCompilerException("Node was already replaced");
150 }
151 checkReplacement(this.node, node);
152 this.node = node;
153 didChange = replaced = true;
154 }
155
156 protected JsNode traverse(JsNode node) {
157 this.node = node;
158 replaced = false;
159 doTraverse(node, this);
160 return this.node;
161 }
162 }
163
164 protected static void checkReplacement(JsNode origNode, JsNode newNode) {
165 if (newNode == null) {
166 throw new InternalCompilerException("Cannot replace with null");
167 }
168 if (newNode == origNode) {
169 throw new InternalCompilerException(
170 "The replacement is the same as the original");
171 }
172 }
173
174 protected boolean didChange = false;
175
176 private final ContextPool listContextPool = new ContextPool(
177 new ContextFactory() {
178 public JsContext create() {
179 return new ListContext();
180 }
181 });
182
183 private final ContextPool nodeContextPool = new ContextPool(
184 new ContextFactory() {
185 public JsContext create() {
186 return new NodeContext();
187 }
188 });
189
190 public boolean didChange() {
191 return didChange;
192 }
193
194 protected JsNode doAccept(JsNode node) {
195 NodeContext ctx = (NodeContext) nodeContextPool.take();
196 try {
197 return ctx.traverse(node);
198 } finally {
199 nodeContextPool.release(ctx);
200 }
201 }
202
203 protected void doAccept(JsCollection collection) {
204 NodeContext ctx = (NodeContext) nodeContextPool.take();
205 try {
206 for (int i = 0, c = collection.size(); i < c; ++i) {
207 collection.setNode(i, ctx.traverse(collection.getNode(i)));
208 }
209 } finally {
210 nodeContextPool.release(ctx);
211 }
212 }
213
214 protected void doAcceptWithInsertRemove(JsCollection collection) {
215 ListContext ctx = (ListContext) listContextPool.take();
216 try {
217 ctx.traverse(collection);
218 } finally {
219 listContextPool.release(ctx);
220 }
221 }
222
223 }
224 |
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