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1 package gnu.expr;
2 import gnu.text.SourceMessages;
3
4
5
6 public class ExpWalker
7 implements gnu.text.SourceLocator
8 {
9 protected SourceMessages messages;
10 Compilation comp;
11
12
13 public Compilation getCompilation () { return comp; }
14
15 public SourceMessages getMessages () { return messages; }
16
17 protected Expression walkExpression (Expression exp)
18 {
19 exp.walkChildren(this);
20 return exp;
21 }
22
23 public void setContext (Compilation comp)
24 {
25 this.comp = comp;
26 messages = comp.getMessages();
27 }
28
29
34 public Expression walk(Expression exp)
35 {
36 int line = exp.getLineNumber();
37 if (messages != null && line > 0)
38 {
39 String  saveFile = messages.getFileName();
40 int saveLine = messages.getLineNumber();
41 int saveColumn = messages.getColumnNumber();
42 messages.setLine(exp.getFileName(), line, exp.getColumnNumber());
43 Expression ret = exp.walk(this);
44 messages.setLine(saveFile, saveLine, saveColumn);
45 return ret;
46 }
47 return exp.walk(this);
48 }
49
50 protected Expression walkApplyExp (ApplyExp exp)
51 {
52 return walkExpression(exp);
53 }
54
55 protected Expression walkIfExp (IfExp exp)
56 {
57 return walkExpression(exp);
58 }
59
60 protected final void walkDeclarationType (Declaration decl)
61 {
62 Expression texp1 = decl.getTypeExp();
63 if (texp1 != null)
64 {
65 Expression texp2 = texp1.walk(this);
66 if (texp2 != texp1)
67 decl.setTypeExp(texp2);
68 }
69 }
70
71 protected final void walkDeclarationTypes (ScopeExp exp)
72 {
73 for (Declaration decl = exp.firstDecl(); decl != null;
74 decl = decl.nextDecl())
75 {
76 walkDeclarationType(decl);
77 }
78 }
79
80 protected Expression walkScopeExp (ScopeExp exp)
81 {
82 walkDeclarationTypes(exp);
83 return walkExpression(exp);
84 }
85
86 protected Expression walkLetExp (LetExp exp) { return walkScopeExp(exp); }
87 protected Expression walkLambdaExp (LambdaExp exp) { return walkScopeExp(exp); }
88 protected Expression walkClassExp (ClassExp exp) { return walkLambdaExp(exp); }
89 protected Expression walkObjectExp (ObjectExp exp) { return walkClassExp(exp); }
90 protected Expression walkModuleExp (ModuleExp exp) { return walkLambdaExp(exp); }
91
92 protected Expression walkSetExp (SetExp exp)
93 {
94 Declaration decl = exp.binding;
95 boolean updateNeeded = decl != null && decl.value == exp.new_value;
96 Expression ret = walkExpression(exp);
97 if (updateNeeded && exp.isDefining())
100 {
101 decl.value = exp.new_value;
102 if (exp.new_value instanceof LambdaExp)
103 ((LambdaExp) exp.new_value).nameDecl = decl;
104 }
105 return ret;
106 }
107
108 protected Expression walkTryExp (TryExp exp) { return walkExpression(exp); }
110 protected Expression walkBeginExp (BeginExp exp) { return walkExpression(exp); }
111 protected Expression walkQuoteExp (QuoteExp exp) { return walkExpression(exp); }
112 protected Expression walkReferenceExp (ReferenceExp exp)
113 { return walkExpression(exp); }
114 protected Expression walkThisExp (ThisExp exp) { return walkReferenceExp(exp); }
115 protected Expression walkSynchronizedExp (SynchronizedExp exp)
116 { return walkExpression(exp); }
117
118 protected Expression walkBlockExp(BlockExp exp) { return walkExpression(exp); }
119 protected Expression walkExitExp(ExitExp exp) { return walkExpression(exp); }
120 protected Expression walkFluidLetExp(FluidLetExp exp)
121 {
122 return walkLetExp(exp);
123 }
124 protected Expression walkLangExp (LangExp exp)
125 { return walkExpression(exp); }
126
127 protected LambdaExp currentLambda = null;
128
129
130 Object exitValue = null;
131
132 public final LambdaExp getCurrentLambda() { return currentLambda; }
133
134 public Expression[] walkExps (Expression[] exps)
135 {
136 return walkExps(exps, exps.length);
137 }
138
139
142 public Expression[] walkExps (Expression[] exps, int n)
143 {
144 String saveFile;
145 int saveLine;
146 int saveColumn;
147 if (messages != null)
148 {
149 saveFile = messages.getFileName();
150 saveLine = messages.getLineNumber();
151 saveColumn = messages.getColumnNumber();
152 }
153 else
154 {
155 saveFile = null;
156 saveLine = 0;
157 saveColumn = 0;
158 }
159 boolean mustRestore = false;
160 for (int i = 0; i < n && exitValue == null; i++)
161 {
162 Expression exp = exps[i];
163 int line = exp.getLineNumber();
164 if (messages != null && line > 0)
165 {
166 messages.setLine(exp.getFileName(), line, exp.getColumnNumber());
167 mustRestore = true;
168 }
169 else if (mustRestore)
170 {
171 messages.setLine(saveFile, saveLine, saveColumn);
172 mustRestore = false;
173 }
174 exps[i] = walk(exp);
175 }
176 if (mustRestore)
177 messages.setLine(saveFile, saveLine, saveColumn);
178 return exps;
179 }
180
181 public void walkDefaultArgs (LambdaExp exp)
182 {
183 if (exp.defaultArgs != null)
184 exp.defaultArgs = walkExps(exp.defaultArgs);
185 }
186
187 public void error(char kind, String message)
188 {
189 if (kind == 'w' && comp.getBooleanOption("warn-as-error", false))
190 kind = 'e';
191 if (messages != null)
192 messages.error(kind, message);
193 else
194 new Error ("internal error: "+message);
195 }
196
197 public Expression noteError (String message)
198 {
199 if (messages != null)
200 messages.error('e', message);
201 return new ErrorExp (message);
202 }
203
204 public final String getFileName() { return messages.getFileName(); }
205 public final int getLineNumber() { return messages.getLineNumber(); }
206 public final int getColumnNumber() { return messages.getColumnNumber(); }
207 public String getPublicId() { return messages.getPublicId(); }
208 public String getSystemId() { return messages.getSystemId(); }
209
210
211 public boolean isStableSourceLocation() { return false; }
212
213 public void setFile(String filename) { messages.setFile(filename); }
214 public void setLine(int line) { messages.setLine(line); }
215 public void setColumn(int column) { messages.setColumn(column); }
216
217 public void setLine(String filename, int line, int column)
218 {
219 messages.setLine(filename, line, column);
220 }
221 }
222 |
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