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author | Li Jin <dragon-fly@qq.com> | 2020-06-22 16:50:40 +0800 |
---|---|---|
committer | Li Jin <dragon-fly@qq.com> | 2020-06-22 16:50:40 +0800 |
commit | cd2b60b101a398cb9356d746364e70eaed1860f1 (patch) | |
tree | a1fe71b76faabc4883f16905a94164ce5c23e692 /src/lua/llex.c | |
parent | 88c1052e700f38cf3d8ad82d469da4c487760b7e (diff) | |
download | yuescript-cd2b60b101a398cb9356d746364e70eaed1860f1.tar.gz yuescript-cd2b60b101a398cb9356d746364e70eaed1860f1.tar.bz2 yuescript-cd2b60b101a398cb9356d746364e70eaed1860f1.zip |
add support for local variable declared with attribute 'close' and 'const' for Lua 5.4.
Diffstat (limited to 'src/lua/llex.c')
-rw-r--r-- | src/lua/llex.c | 578 |
1 files changed, 578 insertions, 0 deletions
diff --git a/src/lua/llex.c b/src/lua/llex.c new file mode 100644 index 0000000..90a7951 --- /dev/null +++ b/src/lua/llex.c | |||
@@ -0,0 +1,578 @@ | |||
1 | /* | ||
2 | ** $Id: llex.c $ | ||
3 | ** Lexical Analyzer | ||
4 | ** See Copyright Notice in lua.h | ||
5 | */ | ||
6 | |||
7 | #define llex_c | ||
8 | #define LUA_CORE | ||
9 | |||
10 | #include "lprefix.h" | ||
11 | |||
12 | |||
13 | #include <locale.h> | ||
14 | #include <string.h> | ||
15 | |||
16 | #include "lua.h" | ||
17 | |||
18 | #include "lctype.h" | ||
19 | #include "ldebug.h" | ||
20 | #include "ldo.h" | ||
21 | #include "lgc.h" | ||
22 | #include "llex.h" | ||
23 | #include "lobject.h" | ||
24 | #include "lparser.h" | ||
25 | #include "lstate.h" | ||
26 | #include "lstring.h" | ||
27 | #include "ltable.h" | ||
28 | #include "lzio.h" | ||
29 | |||
30 | |||
31 | |||
32 | #define next(ls) (ls->current = zgetc(ls->z)) | ||
33 | |||
34 | |||
35 | |||
36 | #define currIsNewline(ls) (ls->current == '\n' || ls->current == '\r') | ||
37 | |||
38 | |||
39 | /* ORDER RESERVED */ | ||
40 | static const char *const luaX_tokens [] = { | ||
41 | "and", "break", "do", "else", "elseif", | ||
42 | "end", "false", "for", "function", "goto", "if", | ||
43 | "in", "local", "nil", "not", "or", "repeat", | ||
44 | "return", "then", "true", "until", "while", | ||
45 | "//", "..", "...", "==", ">=", "<=", "~=", | ||
46 | "<<", ">>", "::", "<eof>", | ||
47 | "<number>", "<integer>", "<name>", "<string>" | ||
48 | }; | ||
49 | |||
50 | |||
51 | #define save_and_next(ls) (save(ls, ls->current), next(ls)) | ||
52 | |||
53 | |||
54 | static l_noret lexerror (LexState *ls, const char *msg, int token); | ||
55 | |||
56 | |||
57 | static void save (LexState *ls, int c) { | ||
58 | Mbuffer *b = ls->buff; | ||
59 | if (luaZ_bufflen(b) + 1 > luaZ_sizebuffer(b)) { | ||
60 | size_t newsize; | ||
61 | if (luaZ_sizebuffer(b) >= MAX_SIZE/2) | ||
62 | lexerror(ls, "lexical element too long", 0); | ||
63 | newsize = luaZ_sizebuffer(b) * 2; | ||
64 | luaZ_resizebuffer(ls->L, b, newsize); | ||
65 | } | ||
66 | b->buffer[luaZ_bufflen(b)++] = cast_char(c); | ||
67 | } | ||
68 | |||
69 | |||
70 | void luaX_init (lua_State *L) { | ||
71 | int i; | ||
72 | TString *e = luaS_newliteral(L, LUA_ENV); /* create env name */ | ||
73 | luaC_fix(L, obj2gco(e)); /* never collect this name */ | ||
74 | for (i=0; i<NUM_RESERVED; i++) { | ||
75 | TString *ts = luaS_new(L, luaX_tokens[i]); | ||
76 | luaC_fix(L, obj2gco(ts)); /* reserved words are never collected */ | ||
77 | ts->extra = cast_byte(i+1); /* reserved word */ | ||
78 | } | ||
79 | } | ||
80 | |||
81 | |||
82 | const char *luaX_token2str (LexState *ls, int token) { | ||
83 | if (token < FIRST_RESERVED) { /* single-byte symbols? */ | ||
84 | lua_assert(token == cast_uchar(token)); | ||
85 | if (lisprint(token)) | ||
86 | return luaO_pushfstring(ls->L, "'%c'", token); | ||
87 | else /* control character */ | ||
88 | return luaO_pushfstring(ls->L, "'<\\%d>'", token); | ||
89 | } | ||
90 | else { | ||
91 | const char *s = luaX_tokens[token - FIRST_RESERVED]; | ||
92 | if (token < TK_EOS) /* fixed format (symbols and reserved words)? */ | ||
93 | return luaO_pushfstring(ls->L, "'%s'", s); | ||
94 | else /* names, strings, and numerals */ | ||
95 | return s; | ||
96 | } | ||
97 | } | ||
98 | |||
99 | |||
100 | static const char *txtToken (LexState *ls, int token) { | ||
101 | switch (token) { | ||
102 | case TK_NAME: case TK_STRING: | ||
103 | case TK_FLT: case TK_INT: | ||
104 | save(ls, '\0'); | ||
105 | return luaO_pushfstring(ls->L, "'%s'", luaZ_buffer(ls->buff)); | ||
106 | default: | ||
107 | return luaX_token2str(ls, token); | ||
108 | } | ||
109 | } | ||
110 | |||
111 | |||
112 | static l_noret lexerror (LexState *ls, const char *msg, int token) { | ||
113 | msg = luaG_addinfo(ls->L, msg, ls->source, ls->linenumber); | ||
114 | if (token) | ||
115 | luaO_pushfstring(ls->L, "%s near %s", msg, txtToken(ls, token)); | ||
116 | luaD_throw(ls->L, LUA_ERRSYNTAX); | ||
117 | } | ||
118 | |||
119 | |||
120 | l_noret luaX_syntaxerror (LexState *ls, const char *msg) { | ||
121 | lexerror(ls, msg, ls->t.token); | ||
122 | } | ||
123 | |||
124 | |||
125 | /* | ||
126 | ** creates a new string and anchors it in scanner's table so that | ||
127 | ** it will not be collected until the end of the compilation | ||
128 | ** (by that time it should be anchored somewhere) | ||
129 | */ | ||
130 | TString *luaX_newstring (LexState *ls, const char *str, size_t l) { | ||
131 | lua_State *L = ls->L; | ||
132 | TValue *o; /* entry for 'str' */ | ||
133 | TString *ts = luaS_newlstr(L, str, l); /* create new string */ | ||
134 | setsvalue2s(L, L->top++, ts); /* temporarily anchor it in stack */ | ||
135 | o = luaH_set(L, ls->h, s2v(L->top - 1)); | ||
136 | if (isempty(o)) { /* not in use yet? */ | ||
137 | /* boolean value does not need GC barrier; | ||
138 | table is not a metatable, so it does not need to invalidate cache */ | ||
139 | setbtvalue(o); /* t[string] = true */ | ||
140 | luaC_checkGC(L); | ||
141 | } | ||
142 | else { /* string already present */ | ||
143 | ts = keystrval(nodefromval(o)); /* re-use value previously stored */ | ||
144 | } | ||
145 | L->top--; /* remove string from stack */ | ||
146 | return ts; | ||
147 | } | ||
148 | |||
149 | |||
150 | /* | ||
151 | ** increment line number and skips newline sequence (any of | ||
152 | ** \n, \r, \n\r, or \r\n) | ||
153 | */ | ||
154 | static void inclinenumber (LexState *ls) { | ||
155 | int old = ls->current; | ||
156 | lua_assert(currIsNewline(ls)); | ||
157 | next(ls); /* skip '\n' or '\r' */ | ||
158 | if (currIsNewline(ls) && ls->current != old) | ||
159 | next(ls); /* skip '\n\r' or '\r\n' */ | ||
160 | if (++ls->linenumber >= MAX_INT) | ||
161 | lexerror(ls, "chunk has too many lines", 0); | ||
162 | } | ||
163 | |||
164 | |||
165 | void luaX_setinput (lua_State *L, LexState *ls, ZIO *z, TString *source, | ||
166 | int firstchar) { | ||
167 | ls->t.token = 0; | ||
168 | ls->L = L; | ||
169 | ls->current = firstchar; | ||
170 | ls->lookahead.token = TK_EOS; /* no look-ahead token */ | ||
171 | ls->z = z; | ||
172 | ls->fs = NULL; | ||
173 | ls->linenumber = 1; | ||
174 | ls->lastline = 1; | ||
175 | ls->source = source; | ||
176 | ls->envn = luaS_newliteral(L, LUA_ENV); /* get env name */ | ||
177 | luaZ_resizebuffer(ls->L, ls->buff, LUA_MINBUFFER); /* initialize buffer */ | ||
178 | } | ||
179 | |||
180 | |||
181 | |||
182 | /* | ||
183 | ** ======================================================= | ||
184 | ** LEXICAL ANALYZER | ||
185 | ** ======================================================= | ||
186 | */ | ||
187 | |||
188 | |||
189 | static int check_next1 (LexState *ls, int c) { | ||
190 | if (ls->current == c) { | ||
191 | next(ls); | ||
192 | return 1; | ||
193 | } | ||
194 | else return 0; | ||
195 | } | ||
196 | |||
197 | |||
198 | /* | ||
199 | ** Check whether current char is in set 'set' (with two chars) and | ||
200 | ** saves it | ||
201 | */ | ||
202 | static int check_next2 (LexState *ls, const char *set) { | ||
203 | lua_assert(set[2] == '\0'); | ||
204 | if (ls->current == set[0] || ls->current == set[1]) { | ||
205 | save_and_next(ls); | ||
206 | return 1; | ||
207 | } | ||
208 | else return 0; | ||
209 | } | ||
210 | |||
211 | |||
212 | /* LUA_NUMBER */ | ||
213 | /* | ||
214 | ** This function is quite liberal in what it accepts, as 'luaO_str2num' | ||
215 | ** will reject ill-formed numerals. Roughly, it accepts the following | ||
216 | ** pattern: | ||
217 | ** | ||
218 | ** %d(%x|%.|([Ee][+-]?))* | 0[Xx](%x|%.|([Pp][+-]?))* | ||
219 | ** | ||
220 | ** The only tricky part is to accept [+-] only after a valid exponent | ||
221 | ** mark, to avoid reading '3-4' or '0xe+1' as a single number. | ||
222 | ** | ||
223 | ** The caller might have already read an initial dot. | ||
224 | */ | ||
225 | static int read_numeral (LexState *ls, SemInfo *seminfo) { | ||
226 | TValue obj; | ||
227 | const char *expo = "Ee"; | ||
228 | int first = ls->current; | ||
229 | lua_assert(lisdigit(ls->current)); | ||
230 | save_and_next(ls); | ||
231 | if (first == '0' && check_next2(ls, "xX")) /* hexadecimal? */ | ||
232 | expo = "Pp"; | ||
233 | for (;;) { | ||
234 | if (check_next2(ls, expo)) /* exponent mark? */ | ||
235 | check_next2(ls, "-+"); /* optional exponent sign */ | ||
236 | else if (lisxdigit(ls->current) || ls->current == '.') /* '%x|%.' */ | ||
237 | save_and_next(ls); | ||
238 | else break; | ||
239 | } | ||
240 | if (lislalpha(ls->current)) /* is numeral touching a letter? */ | ||
241 | save_and_next(ls); /* force an error */ | ||
242 | save(ls, '\0'); | ||
243 | if (luaO_str2num(luaZ_buffer(ls->buff), &obj) == 0) /* format error? */ | ||
244 | lexerror(ls, "malformed number", TK_FLT); | ||
245 | if (ttisinteger(&obj)) { | ||
246 | seminfo->i = ivalue(&obj); | ||
247 | return TK_INT; | ||
248 | } | ||
249 | else { | ||
250 | lua_assert(ttisfloat(&obj)); | ||
251 | seminfo->r = fltvalue(&obj); | ||
252 | return TK_FLT; | ||
253 | } | ||
254 | } | ||
255 | |||
256 | |||
257 | /* | ||
258 | ** reads a sequence '[=*[' or ']=*]', leaving the last bracket. | ||
259 | ** If sequence is well formed, return its number of '='s + 2; otherwise, | ||
260 | ** return 1 if there is no '='s or 0 otherwise (an unfinished '[==...'). | ||
261 | */ | ||
262 | static size_t skip_sep (LexState *ls) { | ||
263 | size_t count = 0; | ||
264 | int s = ls->current; | ||
265 | lua_assert(s == '[' || s == ']'); | ||
266 | save_and_next(ls); | ||
267 | while (ls->current == '=') { | ||
268 | save_and_next(ls); | ||
269 | count++; | ||
270 | } | ||
271 | return (ls->current == s) ? count + 2 | ||
272 | : (count == 0) ? 1 | ||
273 | : 0; | ||
274 | } | ||
275 | |||
276 | |||
277 | static void read_long_string (LexState *ls, SemInfo *seminfo, size_t sep) { | ||
278 | int line = ls->linenumber; /* initial line (for error message) */ | ||
279 | save_and_next(ls); /* skip 2nd '[' */ | ||
280 | if (currIsNewline(ls)) /* string starts with a newline? */ | ||
281 | inclinenumber(ls); /* skip it */ | ||
282 | for (;;) { | ||
283 | switch (ls->current) { | ||
284 | case EOZ: { /* error */ | ||
285 | const char *what = (seminfo ? "string" : "comment"); | ||
286 | const char *msg = luaO_pushfstring(ls->L, | ||
287 | "unfinished long %s (starting at line %d)", what, line); | ||
288 | lexerror(ls, msg, TK_EOS); | ||
289 | break; /* to avoid warnings */ | ||
290 | } | ||
291 | case ']': { | ||
292 | if (skip_sep(ls) == sep) { | ||
293 | save_and_next(ls); /* skip 2nd ']' */ | ||
294 | goto endloop; | ||
295 | } | ||
296 | break; | ||
297 | } | ||
298 | case '\n': case '\r': { | ||
299 | save(ls, '\n'); | ||
300 | inclinenumber(ls); | ||
301 | if (!seminfo) luaZ_resetbuffer(ls->buff); /* avoid wasting space */ | ||
302 | break; | ||
303 | } | ||
304 | default: { | ||
305 | if (seminfo) save_and_next(ls); | ||
306 | else next(ls); | ||
307 | } | ||
308 | } | ||
309 | } endloop: | ||
310 | if (seminfo) | ||
311 | seminfo->ts = luaX_newstring(ls, luaZ_buffer(ls->buff) + sep, | ||
312 | luaZ_bufflen(ls->buff) - 2 * sep); | ||
313 | } | ||
314 | |||
315 | |||
316 | static void esccheck (LexState *ls, int c, const char *msg) { | ||
317 | if (!c) { | ||
318 | if (ls->current != EOZ) | ||
319 | save_and_next(ls); /* add current to buffer for error message */ | ||
320 | lexerror(ls, msg, TK_STRING); | ||
321 | } | ||
322 | } | ||
323 | |||
324 | |||
325 | static int gethexa (LexState *ls) { | ||
326 | save_and_next(ls); | ||
327 | esccheck (ls, lisxdigit(ls->current), "hexadecimal digit expected"); | ||
328 | return luaO_hexavalue(ls->current); | ||
329 | } | ||
330 | |||
331 | |||
332 | static int readhexaesc (LexState *ls) { | ||
333 | int r = gethexa(ls); | ||
334 | r = (r << 4) + gethexa(ls); | ||
335 | luaZ_buffremove(ls->buff, 2); /* remove saved chars from buffer */ | ||
336 | return r; | ||
337 | } | ||
338 | |||
339 | |||
340 | static unsigned long readutf8esc (LexState *ls) { | ||
341 | unsigned long r; | ||
342 | int i = 4; /* chars to be removed: '\', 'u', '{', and first digit */ | ||
343 | save_and_next(ls); /* skip 'u' */ | ||
344 | esccheck(ls, ls->current == '{', "missing '{'"); | ||
345 | r = gethexa(ls); /* must have at least one digit */ | ||
346 | while (cast_void(save_and_next(ls)), lisxdigit(ls->current)) { | ||
347 | i++; | ||
348 | esccheck(ls, r <= (0x7FFFFFFFu >> 4), "UTF-8 value too large"); | ||
349 | r = (r << 4) + luaO_hexavalue(ls->current); | ||
350 | } | ||
351 | esccheck(ls, ls->current == '}', "missing '}'"); | ||
352 | next(ls); /* skip '}' */ | ||
353 | luaZ_buffremove(ls->buff, i); /* remove saved chars from buffer */ | ||
354 | return r; | ||
355 | } | ||
356 | |||
357 | |||
358 | static void utf8esc (LexState *ls) { | ||
359 | char buff[UTF8BUFFSZ]; | ||
360 | int n = luaO_utf8esc(buff, readutf8esc(ls)); | ||
361 | for (; n > 0; n--) /* add 'buff' to string */ | ||
362 | save(ls, buff[UTF8BUFFSZ - n]); | ||
363 | } | ||
364 | |||
365 | |||
366 | static int readdecesc (LexState *ls) { | ||
367 | int i; | ||
368 | int r = 0; /* result accumulator */ | ||
369 | for (i = 0; i < 3 && lisdigit(ls->current); i++) { /* read up to 3 digits */ | ||
370 | r = 10*r + ls->current - '0'; | ||
371 | save_and_next(ls); | ||
372 | } | ||
373 | esccheck(ls, r <= UCHAR_MAX, "decimal escape too large"); | ||
374 | luaZ_buffremove(ls->buff, i); /* remove read digits from buffer */ | ||
375 | return r; | ||
376 | } | ||
377 | |||
378 | |||
379 | static void read_string (LexState *ls, int del, SemInfo *seminfo) { | ||
380 | save_and_next(ls); /* keep delimiter (for error messages) */ | ||
381 | while (ls->current != del) { | ||
382 | switch (ls->current) { | ||
383 | case EOZ: | ||
384 | lexerror(ls, "unfinished string", TK_EOS); | ||
385 | break; /* to avoid warnings */ | ||
386 | case '\n': | ||
387 | case '\r': | ||
388 | lexerror(ls, "unfinished string", TK_STRING); | ||
389 | break; /* to avoid warnings */ | ||
390 | case '\\': { /* escape sequences */ | ||
391 | int c; /* final character to be saved */ | ||
392 | save_and_next(ls); /* keep '\\' for error messages */ | ||
393 | switch (ls->current) { | ||
394 | case 'a': c = '\a'; goto read_save; | ||
395 | case 'b': c = '\b'; goto read_save; | ||
396 | case 'f': c = '\f'; goto read_save; | ||
397 | case 'n': c = '\n'; goto read_save; | ||
398 | case 'r': c = '\r'; goto read_save; | ||
399 | case 't': c = '\t'; goto read_save; | ||
400 | case 'v': c = '\v'; goto read_save; | ||
401 | case 'x': c = readhexaesc(ls); goto read_save; | ||
402 | case 'u': utf8esc(ls); goto no_save; | ||
403 | case '\n': case '\r': | ||
404 | inclinenumber(ls); c = '\n'; goto only_save; | ||
405 | case '\\': case '\"': case '\'': | ||
406 | c = ls->current; goto read_save; | ||
407 | case EOZ: goto no_save; /* will raise an error next loop */ | ||
408 | case 'z': { /* zap following span of spaces */ | ||
409 | luaZ_buffremove(ls->buff, 1); /* remove '\\' */ | ||
410 | next(ls); /* skip the 'z' */ | ||
411 | while (lisspace(ls->current)) { | ||
412 | if (currIsNewline(ls)) inclinenumber(ls); | ||
413 | else next(ls); | ||
414 | } | ||
415 | goto no_save; | ||
416 | } | ||
417 | default: { | ||
418 | esccheck(ls, lisdigit(ls->current), "invalid escape sequence"); | ||
419 | c = readdecesc(ls); /* digital escape '\ddd' */ | ||
420 | goto only_save; | ||
421 | } | ||
422 | } | ||
423 | read_save: | ||
424 | next(ls); | ||
425 | /* go through */ | ||
426 | only_save: | ||
427 | luaZ_buffremove(ls->buff, 1); /* remove '\\' */ | ||
428 | save(ls, c); | ||
429 | /* go through */ | ||
430 | no_save: break; | ||
431 | } | ||
432 | default: | ||
433 | save_and_next(ls); | ||
434 | } | ||
435 | } | ||
436 | save_and_next(ls); /* skip delimiter */ | ||
437 | seminfo->ts = luaX_newstring(ls, luaZ_buffer(ls->buff) + 1, | ||
438 | luaZ_bufflen(ls->buff) - 2); | ||
439 | } | ||
440 | |||
441 | |||
442 | static int llex (LexState *ls, SemInfo *seminfo) { | ||
443 | luaZ_resetbuffer(ls->buff); | ||
444 | for (;;) { | ||
445 | switch (ls->current) { | ||
446 | case '\n': case '\r': { /* line breaks */ | ||
447 | inclinenumber(ls); | ||
448 | break; | ||
449 | } | ||
450 | case ' ': case '\f': case '\t': case '\v': { /* spaces */ | ||
451 | next(ls); | ||
452 | break; | ||
453 | } | ||
454 | case '-': { /* '-' or '--' (comment) */ | ||
455 | next(ls); | ||
456 | if (ls->current != '-') return '-'; | ||
457 | /* else is a comment */ | ||
458 | next(ls); | ||
459 | if (ls->current == '[') { /* long comment? */ | ||
460 | size_t sep = skip_sep(ls); | ||
461 | luaZ_resetbuffer(ls->buff); /* 'skip_sep' may dirty the buffer */ | ||
462 | if (sep >= 2) { | ||
463 | read_long_string(ls, NULL, sep); /* skip long comment */ | ||
464 | luaZ_resetbuffer(ls->buff); /* previous call may dirty the buff. */ | ||
465 | break; | ||
466 | } | ||
467 | } | ||
468 | /* else short comment */ | ||
469 | while (!currIsNewline(ls) && ls->current != EOZ) | ||
470 | next(ls); /* skip until end of line (or end of file) */ | ||
471 | break; | ||
472 | } | ||
473 | case '[': { /* long string or simply '[' */ | ||
474 | size_t sep = skip_sep(ls); | ||
475 | if (sep >= 2) { | ||
476 | read_long_string(ls, seminfo, sep); | ||
477 | return TK_STRING; | ||
478 | } | ||
479 | else if (sep == 0) /* '[=...' missing second bracket? */ | ||
480 | lexerror(ls, "invalid long string delimiter", TK_STRING); | ||
481 | return '['; | ||
482 | } | ||
483 | case '=': { | ||
484 | next(ls); | ||
485 | if (check_next1(ls, '=')) return TK_EQ; | ||
486 | else return '='; | ||
487 | } | ||
488 | case '<': { | ||
489 | next(ls); | ||
490 | if (check_next1(ls, '=')) return TK_LE; | ||
491 | else if (check_next1(ls, '<')) return TK_SHL; | ||
492 | else return '<'; | ||
493 | } | ||
494 | case '>': { | ||
495 | next(ls); | ||
496 | if (check_next1(ls, '=')) return TK_GE; | ||
497 | else if (check_next1(ls, '>')) return TK_SHR; | ||
498 | else return '>'; | ||
499 | } | ||
500 | case '/': { | ||
501 | next(ls); | ||
502 | if (check_next1(ls, '/')) return TK_IDIV; | ||
503 | else return '/'; | ||
504 | } | ||
505 | case '~': { | ||
506 | next(ls); | ||
507 | if (check_next1(ls, '=')) return TK_NE; | ||
508 | else return '~'; | ||
509 | } | ||
510 | case ':': { | ||
511 | next(ls); | ||
512 | if (check_next1(ls, ':')) return TK_DBCOLON; | ||
513 | else return ':'; | ||
514 | } | ||
515 | case '"': case '\'': { /* short literal strings */ | ||
516 | read_string(ls, ls->current, seminfo); | ||
517 | return TK_STRING; | ||
518 | } | ||
519 | case '.': { /* '.', '..', '...', or number */ | ||
520 | save_and_next(ls); | ||
521 | if (check_next1(ls, '.')) { | ||
522 | if (check_next1(ls, '.')) | ||
523 | return TK_DOTS; /* '...' */ | ||
524 | else return TK_CONCAT; /* '..' */ | ||
525 | } | ||
526 | else if (!lisdigit(ls->current)) return '.'; | ||
527 | else return read_numeral(ls, seminfo); | ||
528 | } | ||
529 | case '0': case '1': case '2': case '3': case '4': | ||
530 | case '5': case '6': case '7': case '8': case '9': { | ||
531 | return read_numeral(ls, seminfo); | ||
532 | } | ||
533 | case EOZ: { | ||
534 | return TK_EOS; | ||
535 | } | ||
536 | default: { | ||
537 | if (lislalpha(ls->current)) { /* identifier or reserved word? */ | ||
538 | TString *ts; | ||
539 | do { | ||
540 | save_and_next(ls); | ||
541 | } while (lislalnum(ls->current)); | ||
542 | ts = luaX_newstring(ls, luaZ_buffer(ls->buff), | ||
543 | luaZ_bufflen(ls->buff)); | ||
544 | seminfo->ts = ts; | ||
545 | if (isreserved(ts)) /* reserved word? */ | ||
546 | return ts->extra - 1 + FIRST_RESERVED; | ||
547 | else { | ||
548 | return TK_NAME; | ||
549 | } | ||
550 | } | ||
551 | else { /* single-char tokens (+ - / ...) */ | ||
552 | int c = ls->current; | ||
553 | next(ls); | ||
554 | return c; | ||
555 | } | ||
556 | } | ||
557 | } | ||
558 | } | ||
559 | } | ||
560 | |||
561 | |||
562 | void luaX_next (LexState *ls) { | ||
563 | ls->lastline = ls->linenumber; | ||
564 | if (ls->lookahead.token != TK_EOS) { /* is there a look-ahead token? */ | ||
565 | ls->t = ls->lookahead; /* use this one */ | ||
566 | ls->lookahead.token = TK_EOS; /* and discharge it */ | ||
567 | } | ||
568 | else | ||
569 | ls->t.token = llex(ls, &ls->t.seminfo); /* read next token */ | ||
570 | } | ||
571 | |||
572 | |||
573 | int luaX_lookahead (LexState *ls) { | ||
574 | lua_assert(ls->lookahead.token == TK_EOS); | ||
575 | ls->lookahead.token = llex(ls, &ls->lookahead.seminfo); | ||
576 | return ls->lookahead.token; | ||
577 | } | ||
578 | |||