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authorRoberto Ierusalimschy <roberto@inf.puc-rio.br>2013-04-12 15:48:47 -0300
committerRoberto Ierusalimschy <roberto@inf.puc-rio.br>2013-04-12 15:48:47 -0300
commit2ca518141350667e38941eac35b76980095d2fdc (patch)
tree82595f0dfd57df5782905621298c8aae68b46389 /lstrlib.c
parentf5ae26ec6c2eb69f03f316e59c1e1977c52c7c23 (diff)
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Branch 5.2 - new releases for 5.2 go from here, main trunk goes
for next version
Diffstat (limited to 'lstrlib.c')
-rw-r--r--lstrlib.c1019
1 files changed, 1019 insertions, 0 deletions
diff --git a/lstrlib.c b/lstrlib.c
new file mode 100644
index 00000000..fcc61c9a
--- /dev/null
+++ b/lstrlib.c
@@ -0,0 +1,1019 @@
1/*
2** $Id: lstrlib.c,v 1.178 2012/08/14 18:12:34 roberto Exp $
3** Standard library for string operations and pattern-matching
4** See Copyright Notice in lua.h
5*/
6
7
8#include <ctype.h>
9#include <stddef.h>
10#include <stdio.h>
11#include <stdlib.h>
12#include <string.h>
13
14#define lstrlib_c
15#define LUA_LIB
16
17#include "lua.h"
18
19#include "lauxlib.h"
20#include "lualib.h"
21
22
23/*
24** maximum number of captures that a pattern can do during
25** pattern-matching. This limit is arbitrary.
26*/
27#if !defined(LUA_MAXCAPTURES)
28#define LUA_MAXCAPTURES 32
29#endif
30
31
32/* macro to `unsign' a character */
33#define uchar(c) ((unsigned char)(c))
34
35
36
37static int str_len (lua_State *L) {
38 size_t l;
39 luaL_checklstring(L, 1, &l);
40 lua_pushinteger(L, (lua_Integer)l);
41 return 1;
42}
43
44
45/* translate a relative string position: negative means back from end */
46static size_t posrelat (ptrdiff_t pos, size_t len) {
47 if (pos >= 0) return (size_t)pos;
48 else if (0u - (size_t)pos > len) return 0;
49 else return len - ((size_t)-pos) + 1;
50}
51
52
53static int str_sub (lua_State *L) {
54 size_t l;
55 const char *s = luaL_checklstring(L, 1, &l);
56 size_t start = posrelat(luaL_checkinteger(L, 2), l);
57 size_t end = posrelat(luaL_optinteger(L, 3, -1), l);
58 if (start < 1) start = 1;
59 if (end > l) end = l;
60 if (start <= end)
61 lua_pushlstring(L, s + start - 1, end - start + 1);
62 else lua_pushliteral(L, "");
63 return 1;
64}
65
66
67static int str_reverse (lua_State *L) {
68 size_t l, i;
69 luaL_Buffer b;
70 const char *s = luaL_checklstring(L, 1, &l);
71 char *p = luaL_buffinitsize(L, &b, l);
72 for (i = 0; i < l; i++)
73 p[i] = s[l - i - 1];
74 luaL_pushresultsize(&b, l);
75 return 1;
76}
77
78
79static int str_lower (lua_State *L) {
80 size_t l;
81 size_t i;
82 luaL_Buffer b;
83 const char *s = luaL_checklstring(L, 1, &l);
84 char *p = luaL_buffinitsize(L, &b, l);
85 for (i=0; i<l; i++)
86 p[i] = tolower(uchar(s[i]));
87 luaL_pushresultsize(&b, l);
88 return 1;
89}
90
91
92static int str_upper (lua_State *L) {
93 size_t l;
94 size_t i;
95 luaL_Buffer b;
96 const char *s = luaL_checklstring(L, 1, &l);
97 char *p = luaL_buffinitsize(L, &b, l);
98 for (i=0; i<l; i++)
99 p[i] = toupper(uchar(s[i]));
100 luaL_pushresultsize(&b, l);
101 return 1;
102}
103
104
105/* reasonable limit to avoid arithmetic overflow */
106#define MAXSIZE ((~(size_t)0) >> 1)
107
108static int str_rep (lua_State *L) {
109 size_t l, lsep;
110 const char *s = luaL_checklstring(L, 1, &l);
111 int n = luaL_checkint(L, 2);
112 const char *sep = luaL_optlstring(L, 3, "", &lsep);
113 if (n <= 0) lua_pushliteral(L, "");
114 else if (l + lsep < l || l + lsep >= MAXSIZE / n) /* may overflow? */
115 return luaL_error(L, "resulting string too large");
116 else {
117 size_t totallen = n * l + (n - 1) * lsep;
118 luaL_Buffer b;
119 char *p = luaL_buffinitsize(L, &b, totallen);
120 while (n-- > 1) { /* first n-1 copies (followed by separator) */
121 memcpy(p, s, l * sizeof(char)); p += l;
122 if (lsep > 0) { /* avoid empty 'memcpy' (may be expensive) */
123 memcpy(p, sep, lsep * sizeof(char)); p += lsep;
124 }
125 }
126 memcpy(p, s, l * sizeof(char)); /* last copy (not followed by separator) */
127 luaL_pushresultsize(&b, totallen);
128 }
129 return 1;
130}
131
132
133static int str_byte (lua_State *L) {
134 size_t l;
135 const char *s = luaL_checklstring(L, 1, &l);
136 size_t posi = posrelat(luaL_optinteger(L, 2, 1), l);
137 size_t pose = posrelat(luaL_optinteger(L, 3, posi), l);
138 int n, i;
139 if (posi < 1) posi = 1;
140 if (pose > l) pose = l;
141 if (posi > pose) return 0; /* empty interval; return no values */
142 n = (int)(pose - posi + 1);
143 if (posi + n <= pose) /* (size_t -> int) overflow? */
144 return luaL_error(L, "string slice too long");
145 luaL_checkstack(L, n, "string slice too long");
146 for (i=0; i<n; i++)
147 lua_pushinteger(L, uchar(s[posi+i-1]));
148 return n;
149}
150
151
152static int str_char (lua_State *L) {
153 int n = lua_gettop(L); /* number of arguments */
154 int i;
155 luaL_Buffer b;
156 char *p = luaL_buffinitsize(L, &b, n);
157 for (i=1; i<=n; i++) {
158 int c = luaL_checkint(L, i);
159 luaL_argcheck(L, uchar(c) == c, i, "value out of range");
160 p[i - 1] = uchar(c);
161 }
162 luaL_pushresultsize(&b, n);
163 return 1;
164}
165
166
167static int writer (lua_State *L, const void* b, size_t size, void* B) {
168 (void)L;
169 luaL_addlstring((luaL_Buffer*) B, (const char *)b, size);
170 return 0;
171}
172
173
174static int str_dump (lua_State *L) {
175 luaL_Buffer b;
176 luaL_checktype(L, 1, LUA_TFUNCTION);
177 lua_settop(L, 1);
178 luaL_buffinit(L,&b);
179 if (lua_dump(L, writer, &b) != 0)
180 return luaL_error(L, "unable to dump given function");
181 luaL_pushresult(&b);
182 return 1;
183}
184
185
186
187/*
188** {======================================================
189** PATTERN MATCHING
190** =======================================================
191*/
192
193
194#define CAP_UNFINISHED (-1)
195#define CAP_POSITION (-2)
196
197
198typedef struct MatchState {
199 int matchdepth; /* control for recursive depth (to avoid C stack overflow) */
200 const char *src_init; /* init of source string */
201 const char *src_end; /* end ('\0') of source string */
202 const char *p_end; /* end ('\0') of pattern */
203 lua_State *L;
204 int level; /* total number of captures (finished or unfinished) */
205 struct {
206 const char *init;
207 ptrdiff_t len;
208 } capture[LUA_MAXCAPTURES];
209} MatchState;
210
211
212/* recursive function */
213static const char *match (MatchState *ms, const char *s, const char *p);
214
215
216/* maximum recursion depth for 'match' */
217#if !defined(MAXCCALLS)
218#define MAXCCALLS 200
219#endif
220
221
222#define L_ESC '%'
223#define SPECIALS "^$*+?.([%-"
224
225
226static int check_capture (MatchState *ms, int l) {
227 l -= '1';
228 if (l < 0 || l >= ms->level || ms->capture[l].len == CAP_UNFINISHED)
229 return luaL_error(ms->L, "invalid capture index %%%d", l + 1);
230 return l;
231}
232
233
234static int capture_to_close (MatchState *ms) {
235 int level = ms->level;
236 for (level--; level>=0; level--)
237 if (ms->capture[level].len == CAP_UNFINISHED) return level;
238 return luaL_error(ms->L, "invalid pattern capture");
239}
240
241
242static const char *classend (MatchState *ms, const char *p) {
243 switch (*p++) {
244 case L_ESC: {
245 if (p == ms->p_end)
246 luaL_error(ms->L, "malformed pattern (ends with " LUA_QL("%%") ")");
247 return p+1;
248 }
249 case '[': {
250 if (*p == '^') p++;
251 do { /* look for a `]' */
252 if (p == ms->p_end)
253 luaL_error(ms->L, "malformed pattern (missing " LUA_QL("]") ")");
254 if (*(p++) == L_ESC && p < ms->p_end)
255 p++; /* skip escapes (e.g. `%]') */
256 } while (*p != ']');
257 return p+1;
258 }
259 default: {
260 return p;
261 }
262 }
263}
264
265
266static int match_class (int c, int cl) {
267 int res;
268 switch (tolower(cl)) {
269 case 'a' : res = isalpha(c); break;
270 case 'c' : res = iscntrl(c); break;
271 case 'd' : res = isdigit(c); break;
272 case 'g' : res = isgraph(c); break;
273 case 'l' : res = islower(c); break;
274 case 'p' : res = ispunct(c); break;
275 case 's' : res = isspace(c); break;
276 case 'u' : res = isupper(c); break;
277 case 'w' : res = isalnum(c); break;
278 case 'x' : res = isxdigit(c); break;
279 case 'z' : res = (c == 0); break; /* deprecated option */
280 default: return (cl == c);
281 }
282 return (islower(cl) ? res : !res);
283}
284
285
286static int matchbracketclass (int c, const char *p, const char *ec) {
287 int sig = 1;
288 if (*(p+1) == '^') {
289 sig = 0;
290 p++; /* skip the `^' */
291 }
292 while (++p < ec) {
293 if (*p == L_ESC) {
294 p++;
295 if (match_class(c, uchar(*p)))
296 return sig;
297 }
298 else if ((*(p+1) == '-') && (p+2 < ec)) {
299 p+=2;
300 if (uchar(*(p-2)) <= c && c <= uchar(*p))
301 return sig;
302 }
303 else if (uchar(*p) == c) return sig;
304 }
305 return !sig;
306}
307
308
309static int singlematch (MatchState *ms, const char *s, const char *p,
310 const char *ep) {
311 if (s >= ms->src_end)
312 return 0;
313 else {
314 int c = uchar(*s);
315 switch (*p) {
316 case '.': return 1; /* matches any char */
317 case L_ESC: return match_class(c, uchar(*(p+1)));
318 case '[': return matchbracketclass(c, p, ep-1);
319 default: return (uchar(*p) == c);
320 }
321 }
322}
323
324
325static const char *matchbalance (MatchState *ms, const char *s,
326 const char *p) {
327 if (p >= ms->p_end - 1)
328 luaL_error(ms->L, "malformed pattern "
329 "(missing arguments to " LUA_QL("%%b") ")");
330 if (*s != *p) return NULL;
331 else {
332 int b = *p;
333 int e = *(p+1);
334 int cont = 1;
335 while (++s < ms->src_end) {
336 if (*s == e) {
337 if (--cont == 0) return s+1;
338 }
339 else if (*s == b) cont++;
340 }
341 }
342 return NULL; /* string ends out of balance */
343}
344
345
346static const char *max_expand (MatchState *ms, const char *s,
347 const char *p, const char *ep) {
348 ptrdiff_t i = 0; /* counts maximum expand for item */
349 while (singlematch(ms, s + i, p, ep))
350 i++;
351 /* keeps trying to match with the maximum repetitions */
352 while (i>=0) {
353 const char *res = match(ms, (s+i), ep+1);
354 if (res) return res;
355 i--; /* else didn't match; reduce 1 repetition to try again */
356 }
357 return NULL;
358}
359
360
361static const char *min_expand (MatchState *ms, const char *s,
362 const char *p, const char *ep) {
363 for (;;) {
364 const char *res = match(ms, s, ep+1);
365 if (res != NULL)
366 return res;
367 else if (singlematch(ms, s, p, ep))
368 s++; /* try with one more repetition */
369 else return NULL;
370 }
371}
372
373
374static const char *start_capture (MatchState *ms, const char *s,
375 const char *p, int what) {
376 const char *res;
377 int level = ms->level;
378 if (level >= LUA_MAXCAPTURES) luaL_error(ms->L, "too many captures");
379 ms->capture[level].init = s;
380 ms->capture[level].len = what;
381 ms->level = level+1;
382 if ((res=match(ms, s, p)) == NULL) /* match failed? */
383 ms->level--; /* undo capture */
384 return res;
385}
386
387
388static const char *end_capture (MatchState *ms, const char *s,
389 const char *p) {
390 int l = capture_to_close(ms);
391 const char *res;
392 ms->capture[l].len = s - ms->capture[l].init; /* close capture */
393 if ((res = match(ms, s, p)) == NULL) /* match failed? */
394 ms->capture[l].len = CAP_UNFINISHED; /* undo capture */
395 return res;
396}
397
398
399static const char *match_capture (MatchState *ms, const char *s, int l) {
400 size_t len;
401 l = check_capture(ms, l);
402 len = ms->capture[l].len;
403 if ((size_t)(ms->src_end-s) >= len &&
404 memcmp(ms->capture[l].init, s, len) == 0)
405 return s+len;
406 else return NULL;
407}
408
409
410static const char *match (MatchState *ms, const char *s, const char *p) {
411 if (ms->matchdepth-- == 0)
412 luaL_error(ms->L, "pattern too complex");
413 init: /* using goto's to optimize tail recursion */
414 if (p != ms->p_end) { /* end of pattern? */
415 switch (*p) {
416 case '(': { /* start capture */
417 if (*(p + 1) == ')') /* position capture? */
418 s = start_capture(ms, s, p + 2, CAP_POSITION);
419 else
420 s = start_capture(ms, s, p + 1, CAP_UNFINISHED);
421 break;
422 }
423 case ')': { /* end capture */
424 s = end_capture(ms, s, p + 1);
425 break;
426 }
427 case '$': {
428 if ((p + 1) != ms->p_end) /* is the `$' the last char in pattern? */
429 goto dflt; /* no; go to default */
430 s = (s == ms->src_end) ? s : NULL; /* check end of string */
431 break;
432 }
433 case L_ESC: { /* escaped sequences not in the format class[*+?-]? */
434 switch (*(p + 1)) {
435 case 'b': { /* balanced string? */
436 s = matchbalance(ms, s, p + 2);
437 if (s != NULL) {
438 p += 4; goto init; /* return match(ms, s, p + 4); */
439 } /* else fail (s == NULL) */
440 break;
441 }
442 case 'f': { /* frontier? */
443 const char *ep; char previous;
444 p += 2;
445 if (*p != '[')
446 luaL_error(ms->L, "missing " LUA_QL("[") " after "
447 LUA_QL("%%f") " in pattern");
448 ep = classend(ms, p); /* points to what is next */
449 previous = (s == ms->src_init) ? '\0' : *(s - 1);
450 if (!matchbracketclass(uchar(previous), p, ep - 1) &&
451 matchbracketclass(uchar(*s), p, ep - 1)) {
452 p = ep; goto init; /* return match(ms, s, ep); */
453 }
454 s = NULL; /* match failed */
455 break;
456 }
457 case '0': case '1': case '2': case '3':
458 case '4': case '5': case '6': case '7':
459 case '8': case '9': { /* capture results (%0-%9)? */
460 s = match_capture(ms, s, uchar(*(p + 1)));
461 if (s != NULL) {
462 p += 2; goto init; /* return match(ms, s, p + 2) */
463 }
464 break;
465 }
466 default: goto dflt;
467 }
468 break;
469 }
470 default: dflt: { /* pattern class plus optional suffix */
471 const char *ep = classend(ms, p); /* points to optional suffix */
472 /* does not match at least once? */
473 if (!singlematch(ms, s, p, ep)) {
474 if (*ep == '*' || *ep == '?' || *ep == '-') { /* accept empty? */
475 p = ep + 1; goto init; /* return match(ms, s, ep + 1); */
476 }
477 else /* '+' or no suffix */
478 s = NULL; /* fail */
479 }
480 else { /* matched once */
481 switch (*ep) { /* handle optional suffix */
482 case '?': { /* optional */
483 const char *res;
484 if ((res = match(ms, s + 1, ep + 1)) != NULL)
485 s = res;
486 else {
487 p = ep + 1; goto init; /* else return match(ms, s, ep + 1); */
488 }
489 break;
490 }
491 case '+': /* 1 or more repetitions */
492 s++; /* 1 match already done */
493 /* go through */
494 case '*': /* 0 or more repetitions */
495 s = max_expand(ms, s, p, ep);
496 break;
497 case '-': /* 0 or more repetitions (minimum) */
498 s = min_expand(ms, s, p, ep);
499 break;
500 default: /* no suffix */
501 s++; p = ep; goto init; /* return match(ms, s + 1, ep); */
502 }
503 }
504 break;
505 }
506 }
507 }
508 ms->matchdepth++;
509 return s;
510}
511
512
513
514static const char *lmemfind (const char *s1, size_t l1,
515 const char *s2, size_t l2) {
516 if (l2 == 0) return s1; /* empty strings are everywhere */
517 else if (l2 > l1) return NULL; /* avoids a negative `l1' */
518 else {
519 const char *init; /* to search for a `*s2' inside `s1' */
520 l2--; /* 1st char will be checked by `memchr' */
521 l1 = l1-l2; /* `s2' cannot be found after that */
522 while (l1 > 0 && (init = (const char *)memchr(s1, *s2, l1)) != NULL) {
523 init++; /* 1st char is already checked */
524 if (memcmp(init, s2+1, l2) == 0)
525 return init-1;
526 else { /* correct `l1' and `s1' to try again */
527 l1 -= init-s1;
528 s1 = init;
529 }
530 }
531 return NULL; /* not found */
532 }
533}
534
535
536static void push_onecapture (MatchState *ms, int i, const char *s,
537 const char *e) {
538 if (i >= ms->level) {
539 if (i == 0) /* ms->level == 0, too */
540 lua_pushlstring(ms->L, s, e - s); /* add whole match */
541 else
542 luaL_error(ms->L, "invalid capture index");
543 }
544 else {
545 ptrdiff_t l = ms->capture[i].len;
546 if (l == CAP_UNFINISHED) luaL_error(ms->L, "unfinished capture");
547 if (l == CAP_POSITION)
548 lua_pushinteger(ms->L, ms->capture[i].init - ms->src_init + 1);
549 else
550 lua_pushlstring(ms->L, ms->capture[i].init, l);
551 }
552}
553
554
555static int push_captures (MatchState *ms, const char *s, const char *e) {
556 int i;
557 int nlevels = (ms->level == 0 && s) ? 1 : ms->level;
558 luaL_checkstack(ms->L, nlevels, "too many captures");
559 for (i = 0; i < nlevels; i++)
560 push_onecapture(ms, i, s, e);
561 return nlevels; /* number of strings pushed */
562}
563
564
565/* check whether pattern has no special characters */
566static int nospecials (const char *p, size_t l) {
567 size_t upto = 0;
568 do {
569 if (strpbrk(p + upto, SPECIALS))
570 return 0; /* pattern has a special character */
571 upto += strlen(p + upto) + 1; /* may have more after \0 */
572 } while (upto <= l);
573 return 1; /* no special chars found */
574}
575
576
577static int str_find_aux (lua_State *L, int find) {
578 size_t ls, lp;
579 const char *s = luaL_checklstring(L, 1, &ls);
580 const char *p = luaL_checklstring(L, 2, &lp);
581 size_t init = posrelat(luaL_optinteger(L, 3, 1), ls);
582 if (init < 1) init = 1;
583 else if (init > ls + 1) { /* start after string's end? */
584 lua_pushnil(L); /* cannot find anything */
585 return 1;
586 }
587 /* explicit request or no special characters? */
588 if (find && (lua_toboolean(L, 4) || nospecials(p, lp))) {
589 /* do a plain search */
590 const char *s2 = lmemfind(s + init - 1, ls - init + 1, p, lp);
591 if (s2) {
592 lua_pushinteger(L, s2 - s + 1);
593 lua_pushinteger(L, s2 - s + lp);
594 return 2;
595 }
596 }
597 else {
598 MatchState ms;
599 const char *s1 = s + init - 1;
600 int anchor = (*p == '^');
601 if (anchor) {
602 p++; lp--; /* skip anchor character */
603 }
604 ms.L = L;
605 ms.matchdepth = MAXCCALLS;
606 ms.src_init = s;
607 ms.src_end = s + ls;
608 ms.p_end = p + lp;
609 do {
610 const char *res;
611 ms.level = 0;
612 lua_assert(ms.matchdepth == MAXCCALLS);
613 if ((res=match(&ms, s1, p)) != NULL) {
614 if (find) {
615 lua_pushinteger(L, s1 - s + 1); /* start */
616 lua_pushinteger(L, res - s); /* end */
617 return push_captures(&ms, NULL, 0) + 2;
618 }
619 else
620 return push_captures(&ms, s1, res);
621 }
622 } while (s1++ < ms.src_end && !anchor);
623 }
624 lua_pushnil(L); /* not found */
625 return 1;
626}
627
628
629static int str_find (lua_State *L) {
630 return str_find_aux(L, 1);
631}
632
633
634static int str_match (lua_State *L) {
635 return str_find_aux(L, 0);
636}
637
638
639static int gmatch_aux (lua_State *L) {
640 MatchState ms;
641 size_t ls, lp;
642 const char *s = lua_tolstring(L, lua_upvalueindex(1), &ls);
643 const char *p = lua_tolstring(L, lua_upvalueindex(2), &lp);
644 const char *src;
645 ms.L = L;
646 ms.matchdepth = MAXCCALLS;
647 ms.src_init = s;
648 ms.src_end = s+ls;
649 ms.p_end = p + lp;
650 for (src = s + (size_t)lua_tointeger(L, lua_upvalueindex(3));
651 src <= ms.src_end;
652 src++) {
653 const char *e;
654 ms.level = 0;
655 lua_assert(ms.matchdepth == MAXCCALLS);
656 if ((e = match(&ms, src, p)) != NULL) {
657 lua_Integer newstart = e-s;
658 if (e == src) newstart++; /* empty match? go at least one position */
659 lua_pushinteger(L, newstart);
660 lua_replace(L, lua_upvalueindex(3));
661 return push_captures(&ms, src, e);
662 }
663 }
664 return 0; /* not found */
665}
666
667
668static int gmatch (lua_State *L) {
669 luaL_checkstring(L, 1);
670 luaL_checkstring(L, 2);
671 lua_settop(L, 2);
672 lua_pushinteger(L, 0);
673 lua_pushcclosure(L, gmatch_aux, 3);
674 return 1;
675}
676
677
678static void add_s (MatchState *ms, luaL_Buffer *b, const char *s,
679 const char *e) {
680 size_t l, i;
681 const char *news = lua_tolstring(ms->L, 3, &l);
682 for (i = 0; i < l; i++) {
683 if (news[i] != L_ESC)
684 luaL_addchar(b, news[i]);
685 else {
686 i++; /* skip ESC */
687 if (!isdigit(uchar(news[i]))) {
688 if (news[i] != L_ESC)
689 luaL_error(ms->L, "invalid use of " LUA_QL("%c")
690 " in replacement string", L_ESC);
691 luaL_addchar(b, news[i]);
692 }
693 else if (news[i] == '0')
694 luaL_addlstring(b, s, e - s);
695 else {
696 push_onecapture(ms, news[i] - '1', s, e);
697 luaL_addvalue(b); /* add capture to accumulated result */
698 }
699 }
700 }
701}
702
703
704static void add_value (MatchState *ms, luaL_Buffer *b, const char *s,
705 const char *e, int tr) {
706 lua_State *L = ms->L;
707 switch (tr) {
708 case LUA_TFUNCTION: {
709 int n;
710 lua_pushvalue(L, 3);
711 n = push_captures(ms, s, e);
712 lua_call(L, n, 1);
713 break;
714 }
715 case LUA_TTABLE: {
716 push_onecapture(ms, 0, s, e);
717 lua_gettable(L, 3);
718 break;
719 }
720 default: { /* LUA_TNUMBER or LUA_TSTRING */
721 add_s(ms, b, s, e);
722 return;
723 }
724 }
725 if (!lua_toboolean(L, -1)) { /* nil or false? */
726 lua_pop(L, 1);
727 lua_pushlstring(L, s, e - s); /* keep original text */
728 }
729 else if (!lua_isstring(L, -1))
730 luaL_error(L, "invalid replacement value (a %s)", luaL_typename(L, -1));
731 luaL_addvalue(b); /* add result to accumulator */
732}
733
734
735static int str_gsub (lua_State *L) {
736 size_t srcl, lp;
737 const char *src = luaL_checklstring(L, 1, &srcl);
738 const char *p = luaL_checklstring(L, 2, &lp);
739 int tr = lua_type(L, 3);
740 size_t max_s = luaL_optinteger(L, 4, srcl+1);
741 int anchor = (*p == '^');
742 size_t n = 0;
743 MatchState ms;
744 luaL_Buffer b;
745 luaL_argcheck(L, tr == LUA_TNUMBER || tr == LUA_TSTRING ||
746 tr == LUA_TFUNCTION || tr == LUA_TTABLE, 3,
747 "string/function/table expected");
748 luaL_buffinit(L, &b);
749 if (anchor) {
750 p++; lp--; /* skip anchor character */
751 }
752 ms.L = L;
753 ms.matchdepth = MAXCCALLS;
754 ms.src_init = src;
755 ms.src_end = src+srcl;
756 ms.p_end = p + lp;
757 while (n < max_s) {
758 const char *e;
759 ms.level = 0;
760 lua_assert(ms.matchdepth == MAXCCALLS);
761 e = match(&ms, src, p);
762 if (e) {
763 n++;
764 add_value(&ms, &b, src, e, tr);
765 }
766 if (e && e>src) /* non empty match? */
767 src = e; /* skip it */
768 else if (src < ms.src_end)
769 luaL_addchar(&b, *src++);
770 else break;
771 if (anchor) break;
772 }
773 luaL_addlstring(&b, src, ms.src_end-src);
774 luaL_pushresult(&b);
775 lua_pushinteger(L, n); /* number of substitutions */
776 return 2;
777}
778
779/* }====================================================== */
780
781
782
783/*
784** {======================================================
785** STRING FORMAT
786** =======================================================
787*/
788
789/*
790** LUA_INTFRMLEN is the length modifier for integer conversions in
791** 'string.format'; LUA_INTFRM_T is the integer type corresponding to
792** the previous length
793*/
794#if !defined(LUA_INTFRMLEN) /* { */
795#if defined(LUA_USE_LONGLONG)
796
797#define LUA_INTFRMLEN "ll"
798#define LUA_INTFRM_T long long
799
800#else
801
802#define LUA_INTFRMLEN "l"
803#define LUA_INTFRM_T long
804
805#endif
806#endif /* } */
807
808
809/*
810** LUA_FLTFRMLEN is the length modifier for float conversions in
811** 'string.format'; LUA_FLTFRM_T is the float type corresponding to
812** the previous length
813*/
814#if !defined(LUA_FLTFRMLEN)
815
816#define LUA_FLTFRMLEN ""
817#define LUA_FLTFRM_T double
818
819#endif
820
821
822/* maximum size of each formatted item (> len(format('%99.99f', -1e308))) */
823#define MAX_ITEM 512
824/* valid flags in a format specification */
825#define FLAGS "-+ #0"
826/*
827** maximum size of each format specification (such as '%-099.99d')
828** (+10 accounts for %99.99x plus margin of error)
829*/
830#define MAX_FORMAT (sizeof(FLAGS) + sizeof(LUA_INTFRMLEN) + 10)
831
832
833static void addquoted (lua_State *L, luaL_Buffer *b, int arg) {
834 size_t l;
835 const char *s = luaL_checklstring(L, arg, &l);
836 luaL_addchar(b, '"');
837 while (l--) {
838 if (*s == '"' || *s == '\\' || *s == '\n') {
839 luaL_addchar(b, '\\');
840 luaL_addchar(b, *s);
841 }
842 else if (*s == '\0' || iscntrl(uchar(*s))) {
843 char buff[10];
844 if (!isdigit(uchar(*(s+1))))
845 sprintf(buff, "\\%d", (int)uchar(*s));
846 else
847 sprintf(buff, "\\%03d", (int)uchar(*s));
848 luaL_addstring(b, buff);
849 }
850 else
851 luaL_addchar(b, *s);
852 s++;
853 }
854 luaL_addchar(b, '"');
855}
856
857static const char *scanformat (lua_State *L, const char *strfrmt, char *form) {
858 const char *p = strfrmt;
859 while (*p != '\0' && strchr(FLAGS, *p) != NULL) p++; /* skip flags */
860 if ((size_t)(p - strfrmt) >= sizeof(FLAGS)/sizeof(char))
861 luaL_error(L, "invalid format (repeated flags)");
862 if (isdigit(uchar(*p))) p++; /* skip width */
863 if (isdigit(uchar(*p))) p++; /* (2 digits at most) */
864 if (*p == '.') {
865 p++;
866 if (isdigit(uchar(*p))) p++; /* skip precision */
867 if (isdigit(uchar(*p))) p++; /* (2 digits at most) */
868 }
869 if (isdigit(uchar(*p)))
870 luaL_error(L, "invalid format (width or precision too long)");
871 *(form++) = '%';
872 memcpy(form, strfrmt, (p - strfrmt + 1) * sizeof(char));
873 form += p - strfrmt + 1;
874 *form = '\0';
875 return p;
876}
877
878
879/*
880** add length modifier into formats
881*/
882static void addlenmod (char *form, const char *lenmod) {
883 size_t l = strlen(form);
884 size_t lm = strlen(lenmod);
885 char spec = form[l - 1];
886 strcpy(form + l - 1, lenmod);
887 form[l + lm - 1] = spec;
888 form[l + lm] = '\0';
889}
890
891
892static int str_format (lua_State *L) {
893 int top = lua_gettop(L);
894 int arg = 1;
895 size_t sfl;
896 const char *strfrmt = luaL_checklstring(L, arg, &sfl);
897 const char *strfrmt_end = strfrmt+sfl;
898 luaL_Buffer b;
899 luaL_buffinit(L, &b);
900 while (strfrmt < strfrmt_end) {
901 if (*strfrmt != L_ESC)
902 luaL_addchar(&b, *strfrmt++);
903 else if (*++strfrmt == L_ESC)
904 luaL_addchar(&b, *strfrmt++); /* %% */
905 else { /* format item */
906 char form[MAX_FORMAT]; /* to store the format (`%...') */
907 char *buff = luaL_prepbuffsize(&b, MAX_ITEM); /* to put formatted item */
908 int nb = 0; /* number of bytes in added item */
909 if (++arg > top)
910 luaL_argerror(L, arg, "no value");
911 strfrmt = scanformat(L, strfrmt, form);
912 switch (*strfrmt++) {
913 case 'c': {
914 nb = sprintf(buff, form, luaL_checkint(L, arg));
915 break;
916 }
917 case 'd': case 'i': {
918 lua_Number n = luaL_checknumber(L, arg);
919 LUA_INTFRM_T ni = (LUA_INTFRM_T)n;
920 lua_Number diff = n - (lua_Number)ni;
921 luaL_argcheck(L, -1 < diff && diff < 1, arg,
922 "not a number in proper range");
923 addlenmod(form, LUA_INTFRMLEN);
924 nb = sprintf(buff, form, ni);
925 break;
926 }
927 case 'o': case 'u': case 'x': case 'X': {
928 lua_Number n = luaL_checknumber(L, arg);
929 unsigned LUA_INTFRM_T ni = (unsigned LUA_INTFRM_T)n;
930 lua_Number diff = n - (lua_Number)ni;
931 luaL_argcheck(L, -1 < diff && diff < 1, arg,
932 "not a non-negative number in proper range");
933 addlenmod(form, LUA_INTFRMLEN);
934 nb = sprintf(buff, form, ni);
935 break;
936 }
937 case 'e': case 'E': case 'f':
938#if defined(LUA_USE_AFORMAT)
939 case 'a': case 'A':
940#endif
941 case 'g': case 'G': {
942 addlenmod(form, LUA_FLTFRMLEN);
943 nb = sprintf(buff, form, (LUA_FLTFRM_T)luaL_checknumber(L, arg));
944 break;
945 }
946 case 'q': {
947 addquoted(L, &b, arg);
948 break;
949 }
950 case 's': {
951 size_t l;
952 const char *s = luaL_tolstring(L, arg, &l);
953 if (!strchr(form, '.') && l >= 100) {
954 /* no precision and string is too long to be formatted;
955 keep original string */
956 luaL_addvalue(&b);
957 break;
958 }
959 else {
960 nb = sprintf(buff, form, s);
961 lua_pop(L, 1); /* remove result from 'luaL_tolstring' */
962 break;
963 }
964 }
965 default: { /* also treat cases `pnLlh' */
966 return luaL_error(L, "invalid option " LUA_QL("%%%c") " to "
967 LUA_QL("format"), *(strfrmt - 1));
968 }
969 }
970 luaL_addsize(&b, nb);
971 }
972 }
973 luaL_pushresult(&b);
974 return 1;
975}
976
977/* }====================================================== */
978
979
980static const luaL_Reg strlib[] = {
981 {"byte", str_byte},
982 {"char", str_char},
983 {"dump", str_dump},
984 {"find", str_find},
985 {"format", str_format},
986 {"gmatch", gmatch},
987 {"gsub", str_gsub},
988 {"len", str_len},
989 {"lower", str_lower},
990 {"match", str_match},
991 {"rep", str_rep},
992 {"reverse", str_reverse},
993 {"sub", str_sub},
994 {"upper", str_upper},
995 {NULL, NULL}
996};
997
998
999static void createmetatable (lua_State *L) {
1000 lua_createtable(L, 0, 1); /* table to be metatable for strings */
1001 lua_pushliteral(L, ""); /* dummy string */
1002 lua_pushvalue(L, -2); /* copy table */
1003 lua_setmetatable(L, -2); /* set table as metatable for strings */
1004 lua_pop(L, 1); /* pop dummy string */
1005 lua_pushvalue(L, -2); /* get string library */
1006 lua_setfield(L, -2, "__index"); /* metatable.__index = string */
1007 lua_pop(L, 1); /* pop metatable */
1008}
1009
1010
1011/*
1012** Open string library
1013*/
1014LUAMOD_API int luaopen_string (lua_State *L) {
1015 luaL_newlib(L, strlib);
1016 createmetatable(L);
1017 return 1;
1018}
1019
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