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1
15
16 package javassist.compiler;
17
18 class Token {
19 public Token next = null;
20 public int tokenId;
21
22 public long longValue;
23 public double doubleValue;
24 public String  textValue;
25 }
26
27 public class Lex implements TokenId {
28 private int lastChar;
29 private StringBuffer textBuffer;
30 private Token currentToken;
31 private Token lookAheadTokens;
32
33 private String input;
34 private int position, maxlen, lineNumber;
35
36
39 public Lex(String s) {
40 lastChar = -1;
41 textBuffer = new StringBuffer ();
42 currentToken = new Token();
43 lookAheadTokens = null;
44
45 input = s;
46 position = 0;
47 maxlen = s.length();
48 lineNumber = 0;
49 }
50
51 public int get() {
52 if (lookAheadTokens == null)
53 return get(currentToken);
54 else {
55 Token t;
56 currentToken = t = lookAheadTokens;
57 lookAheadTokens = lookAheadTokens.next;
58 return t.tokenId;
59 }
60 }
61
62
65 public int lookAhead() {
66 return lookAhead(0);
67 }
68
69 public int lookAhead(int i) {
70 Token tk = lookAheadTokens;
71 if (tk == null) {
72 lookAheadTokens = tk = currentToken; tk.next = null;
74 get(tk);
75 }
76
77 for (; i-- > 0; tk = tk.next)
78 if (tk.next == null) {
79 Token tk2;
80 tk.next = tk2 = new Token();
81 get(tk2);
82 }
83
84 currentToken = tk;
85 return tk.tokenId;
86 }
87
88 public String getString() {
89 return currentToken.textValue;
90 }
91
92 public long getLong() {
93 return currentToken.longValue;
94 }
95
96 public double getDouble() {
97 return currentToken.doubleValue;
98 }
99
100 private int get(Token token) {
101 int t;
102 do {
103 t = readLine(token);
104 } while (t == '\n');
105 token.tokenId = t;
106 return t;
107 }
108
109 private int readLine(Token token) {
110 int c = getNextNonWhiteChar();
111 if(c < 0)
112 return c;
113 else if(c == '\n') {
114 ++lineNumber;
115 return '\n';
116 }
117 else if (c == '\'')
118 return readCharConst(token);
119 else if (c == '"')
120 return readStringL(token);
121 else if ('0' <= c && c <= '9')
122 return readNumber(c, token);
123 else if(c == '.'){
124 c = getc();
125 if ('0' <= c && c <= '9') {
126 StringBuffer tbuf = textBuffer;
127 tbuf.setLength(0);
128 tbuf.append('.');
129 return readDouble(tbuf, c, token);
130 }
131 else{
132 ungetc(c);
133 return readSeparator('.');
134 }
135 }
136 else if ('A' <= c && c <= 'Z' || 'a' <= c && c <= 'z' || c == '_'
137 || c == '$')
138 return readIdentifier(c, token);
139 else
140 return readSeparator(c);
141 }
142
143 private int getNextNonWhiteChar() {
144 int c;
145 do {
146 c = getc();
147 if (c == '/') {
148 c = getc();
149 if (c == '/')
150 do {
151 c = getc();
152 } while (c != '\n' && c != '\r' && c != -1);
153 else if (c == '*')
154 while (true) {
155 c = getc();
156 if (c == -1)
157 break;
158 else if (c == '*')
159 if ((c = getc()) == '/') {
160 c = ' ';
161 break;
162 }
163 else
164 ungetc(c);
165 }
166 else {
167 ungetc(c);
168 c = '/';
169 }
170 }
171 } while(isBlank(c));
172 return c;
173 }
174
175 private int readCharConst(Token token) {
176 int c;
177 int value = 0;
178 while ((c = getc()) != '\'')
179 if (c == '\\')
180 value = readEscapeChar();
181 else if (c < 0x20) {
182 if (c == '\n')
183 ++lineNumber;
184
185 return BadToken;
186 }
187 else
188 value = c;
189
190 token.longValue = value;
191 return CharConstant;
192 }
193
194 private int readEscapeChar() {
195 int c = getc();
196 if (c == 'n')
197 c = '\n';
198 else if (c == 't')
199 c = '\t';
200 else if (c == 'r')
201 c = '\r';
202 else if (c == 'f')
203 c = '\f';
204 else if (c == '\n')
205 ++lineNumber;
206
207 return c;
208 }
209
210 private int readStringL(Token token) {
211 int c;
212 StringBuffer tbuf = textBuffer;
213 tbuf.setLength(0);
214 for (;;) {
215 while ((c = getc()) != '"') {
216 if (c == '\\')
217 c = readEscapeChar();
218 else if (c == '\n' || c < 0) {
219 ++lineNumber;
220 return BadToken;
221 }
222
223 tbuf.append((char)c);
224 }
225
226 for (;;) {
227 c = getc();
228 if (c == '\n')
229 ++lineNumber;
230 else if (!isBlank(c))
231 break;
232 }
233
234 if (c != '"') {
235 ungetc(c);
236 break;
237 }
238 }
239
240 token.textValue = tbuf.toString();
241 return StringL;
242 }
243
244 private int readNumber(int c, Token token) {
245 long value = 0;
246 int c2 = getc();
247 if (c == '0')
248 if (c2 == 'X' || c2 == 'x')
249 for (;;) {
250 c = getc();
251 if ('0' <= c && c <= '9')
252 value = value * 16 + (long)(c - '0');
253 else if ('A' <= c && c <= 'F')
254 value = value * 16 + (long)(c - 'A' + 10);
255 else if ('a' <= c && c <= 'f')
256 value = value * 16 + (long)(c - 'a' + 10);
257 else {
258 token.longValue = value;
259 if (c == 'L' || c == 'l')
260 return LongConstant;
261 else {
262 ungetc(c);
263 return IntConstant;
264 }
265 }
266 }
267 else if ('0' <= c2 && c2 <= '7') {
268 value = c2 - '0';
269 for (;;) {
270 c = getc();
271 if ('0' <= c && c <= '7')
272 value = value * 8 + (long)(c - '0');
273 else {
274 token.longValue = value;
275 if (c == 'L' || c == 'l')
276 return LongConstant;
277 else {
278 ungetc(c);
279 return IntConstant;
280 }
281 }
282 }
283 }
284
285 value = c - '0';
286 while ('0' <= c2 && c2 <= '9') {
287 value = value * 10 + c2 - '0';
288 c2 = getc();
289 }
290
291 token.longValue = value;
292 if (c2 == 'F' || c2 == 'f') {
293 token.doubleValue = (double)value;
294 return FloatConstant;
295 }
296 else if (c2 == 'E' || c2 == 'e'
297 || c2 == 'D' || c2 == 'd' || c2 == '.') {
298 StringBuffer tbuf = textBuffer;
299 tbuf.setLength(0);
300 tbuf.append(value);
301 return readDouble(tbuf, c2, token);
302 }
303 else if (c2 == 'L' || c2 == 'l')
304 return LongConstant;
305 else {
306 ungetc(c2);
307 return IntConstant;
308 }
309 }
310
311 private int readDouble(StringBuffer sbuf, int c, Token token) {
312 if (c != 'E' && c != 'e' && c != 'D' && c != 'd') {
313 sbuf.append((char)c);
314 for (;;) {
315 c = getc();
316 if ('0' <= c && c <= '9')
317 sbuf.append((char)c);
318 else
319 break;
320 }
321 }
322
323 if (c == 'E' || c == 'e') {
324 sbuf.append((char)c);
325 c = getc();
326 if (c == '+' || c == '-') {
327 sbuf.append((char)c);
328 c = getc();
329 }
330
331 while ('0' <= c && c <= '9') {
332 sbuf.append((char)c);
333 c = getc();
334 }
335 }
336
337 try {
338 token.doubleValue = Double.parseDouble(sbuf.toString());
339 }
340 catch (NumberFormatException e) {
341 return BadToken;
342 }
343
344 if (c == 'F' || c == 'f')
345 return FloatConstant;
346 else {
347 if (c != 'D' && c != 'd')
348 ungetc(c);
349
350 return DoubleConstant;
351 }
352 }
353
354 private static final int[] equalOps
356 = { NEQ, 0, 0, 0, MOD_E, AND_E, 0, 0,
357 0, MUL_E, PLUS_E, 0, MINUS_E, 0, DIV_E, 0,
358 0, 0, 0, 0, 0, 0, 0, 0,
359 0, 0, 0, LE, EQ, GE, 0 };
360
361 private int readSeparator(int c) {
362 int c2, c3;
363 if ('!' <= c && c <= '?') {
364 int t = equalOps[c - '!'];
365 if (t == 0)
366 return c;
367 else {
368 c2 = getc();
369 if (c == c2)
370 switch (c) {
371 case '=' :
372 return EQ;
373 case '+' :
374 return PLUSPLUS;
375 case '-' :
376 return MINUSMINUS;
377 case '&' :
378 return ANDAND;
379 case '<' :
380 c3 = getc();
381 if (c3 == '=')
382 return LSHIFT_E;
383 else {
384 ungetc(c3);
385 return LSHIFT;
386 }
387 case '>' :
388 c3 = getc();
389 if (c3 == '=')
390 return RSHIFT_E;
391 else if (c3 == '>') {
392 c3 = getc();
393 if (c3 == '=')
394 return ARSHIFT_E;
395 else {
396 ungetc(c3);
397 return ARSHIFT;
398 }
399 }
400 else {
401 ungetc(c3);
402 return RSHIFT;
403 }
404 default :
405 break;
406 }
407 else if (c2 == '=')
408 return t;
409 }
410 }
411 else if (c == '^') {
412 c2 = getc();
413 if (c2 == '=')
414 return EXOR_E;
415 }
416 else if (c == '|') {
417 c2 = getc();
418 if (c2 == '=')
419 return OR_E;
420 else if (c2 == '|')
421 return OROR;
422 }
423 else
424 return c;
425
426 ungetc(c2);
427 return c;
428 }
429
430 private int readIdentifier(int c, Token token) {
431 StringBuffer tbuf = textBuffer;
432 tbuf.setLength(0);
433
434 do {
435 tbuf.append((char)c);
436 c = getc();
437 } while ('A' <= c && c <= 'Z' || 'a' <= c && c <= 'z' || c == '_'
438 || c == '$' || '0' <= c && c <= '9');
439
440 ungetc(c);
441
442 String name = tbuf.toString();
443 int t = ktable.lookup(name);
444 if (t >= 0)
445 return t;
446 else {
447
454 token.textValue = name;
455 return Identifier;
456 }
457 }
458
459 private static final KeywordTable ktable = new KeywordTable();
460
461 static {
462 ktable.append("abstract", ABSTRACT);
463 ktable.append("boolean", BOOLEAN);
464 ktable.append("break", BREAK);
465 ktable.append("byte", BYTE);
466 ktable.append("case", CASE);
467 ktable.append("catch", CATCH);
468 ktable.append("char", CHAR);
469 ktable.append("class", CLASS);
470 ktable.append("const", CONST);
471 ktable.append("continue", CONTINUE);
472 ktable.append("default", DEFAULT);
473 ktable.append("do", DO);
474 ktable.append("double", DOUBLE);
475 ktable.append("else", ELSE);
476 ktable.append("extends", EXTENDS);
477 ktable.append("false", FALSE);
478 ktable.append("final", FINAL);
479 ktable.append("finally", FINALLY);
480 ktable.append("float", FLOAT);
481 ktable.append("for", FOR);
482 ktable.append("goto", GOTO);
483 ktable.append("if", IF);
484 ktable.append("implements", IMPLEMENTS);
485 ktable.append("import", IMPORT);
486 ktable.append("instanceof", INSTANCEOF);
487 ktable.append("int", INT);
488 ktable.append("interface", INTERFACE);
489 ktable.append("long", LONG);
490 ktable.append("native", NATIVE);
491 ktable.append("new", NEW);
492 ktable.append("null", NULL);
493 ktable.append("package", PACKAGE);
494 ktable.append("private", PRIVATE);
495 ktable.append("protected", PROTECTED);
496 ktable.append("public", PUBLIC);
497 ktable.append("return", RETURN);
498 ktable.append("short", SHORT);
499 ktable.append("static", STATIC);
500 ktable.append("strict", STRICT);
501 ktable.append("super", SUPER);
502 ktable.append("switch", SWITCH);
503 ktable.append("synchronized", SYNCHRONIZED);
504 ktable.append("this", THIS);
505 ktable.append("throw", THROW);
506 ktable.append("throws", THROWS);
507 ktable.append("transient", TRANSIENT);
508 ktable.append("true", TRUE);
509 ktable.append("try", TRY);
510 ktable.append("void", VOID);
511 ktable.append("volatile", VOLATILE);
512 ktable.append("while", WHILE);
513 }
514
515 private static boolean isBlank(int c) {
516 return c == ' ' || c == '\t' || c == '\f' || c == '\r'
517 || c == '\n';
518 }
519
520 private static boolean isDigit(int c) {
521 return '0' <= c && c <= '9';
522 }
523
524 private void ungetc(int c) {
525 lastChar = c;
526 }
527
528 private int getc() {
529 if (lastChar < 0)
530 if (position < maxlen)
531 return input.charAt(position++);
532 else
533 return -1;
534 else {
535 int c = lastChar;
536 lastChar = -1;
537 return c;
538 }
539 }
540 }
541 |
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