Mercurial > vba-clojure
view src/lua/lstrlib.c @ 389:bb8978d370d8
saving progress.
author | Robert McIntyre <rlm@mit.edu> |
---|---|
date | Thu, 12 Apr 2012 12:08:36 -0500 |
parents | 27763b933818 |
children |
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1 /*2 ** $Id: lstrlib.c,v 1.132.1.4 2008/07/11 17:27:21 roberto Exp $3 ** Standard library for string operations and pattern-matching4 ** See Copyright Notice in lua.h5 */8 #include <ctype.h>9 #include <stddef.h>10 #include <stdio.h>11 #include <stdlib.h>12 #include <string.h>14 #define lstrlib_c15 #define LUA_LIB17 #include "lua.h"19 #include "lauxlib.h"20 #include "lualib.h"23 /* macro to `unsign' a character */24 #define uchar(c) ((unsigned char)(c))28 static int str_len (lua_State *L) {29 size_t l;30 luaL_checklstring(L, 1, &l);31 lua_pushinteger(L, l);32 return 1;33 }36 static ptrdiff_t posrelat (ptrdiff_t pos, size_t len) {37 /* relative string position: negative means back from end */38 if (pos < 0) pos += (ptrdiff_t)len + 1;39 return (pos >= 0) ? pos : 0;40 }43 static int str_sub (lua_State *L) {44 size_t l;45 const char *s = luaL_checklstring(L, 1, &l);46 ptrdiff_t start = posrelat(luaL_checkinteger(L, 2), l);47 ptrdiff_t end = posrelat(luaL_optinteger(L, 3, -1), l);48 if (start < 1) start = 1;49 if (end > (ptrdiff_t)l) end = (ptrdiff_t)l;50 if (start <= end)51 lua_pushlstring(L, s+start-1, end-start+1);52 else lua_pushliteral(L, "");53 return 1;54 }57 static int str_reverse (lua_State *L) {58 size_t l;59 luaL_Buffer b;60 const char *s = luaL_checklstring(L, 1, &l);61 luaL_buffinit(L, &b);62 while (l--) luaL_addchar(&b, s[l]);63 luaL_pushresult(&b);64 return 1;65 }68 static int str_lower (lua_State *L) {69 size_t l;70 size_t i;71 luaL_Buffer b;72 const char *s = luaL_checklstring(L, 1, &l);73 luaL_buffinit(L, &b);74 for (i=0; i<l; i++)75 luaL_addchar(&b, tolower(uchar(s[i])));76 luaL_pushresult(&b);77 return 1;78 }81 static int str_upper (lua_State *L) {82 size_t l;83 size_t i;84 luaL_Buffer b;85 const char *s = luaL_checklstring(L, 1, &l);86 luaL_buffinit(L, &b);87 for (i=0; i<l; i++)88 luaL_addchar(&b, toupper(uchar(s[i])));89 luaL_pushresult(&b);90 return 1;91 }93 static int str_rep (lua_State *L) {94 size_t l;95 luaL_Buffer b;96 const char *s = luaL_checklstring(L, 1, &l);97 int n = luaL_checkint(L, 2);98 luaL_buffinit(L, &b);99 while (n-- > 0)100 luaL_addlstring(&b, s, l);101 luaL_pushresult(&b);102 return 1;103 }106 static int str_byte (lua_State *L) {107 size_t l;108 const char *s = luaL_checklstring(L, 1, &l);109 ptrdiff_t posi = posrelat(luaL_optinteger(L, 2, 1), l);110 ptrdiff_t pose = posrelat(luaL_optinteger(L, 3, posi), l);111 int n, i;112 if (posi <= 0) posi = 1;113 if ((size_t)pose > l) pose = l;114 if (posi > pose) return 0; /* empty interval; return no values */115 n = (int)(pose - posi + 1);116 if (posi + n <= pose) /* overflow? */117 luaL_error(L, "string slice too long");118 luaL_checkstack(L, n, "string slice too long");119 for (i=0; i<n; i++)120 lua_pushinteger(L, uchar(s[posi+i-1]));121 return n;122 }125 static int str_char (lua_State *L) {126 int n = lua_gettop(L); /* number of arguments */127 int i;128 luaL_Buffer b;129 luaL_buffinit(L, &b);130 for (i=1; i<=n; i++) {131 int c = luaL_checkint(L, i);132 luaL_argcheck(L, uchar(c) == c, i, "invalid value");133 luaL_addchar(&b, uchar(c));134 }135 luaL_pushresult(&b);136 return 1;137 }140 static int writer (lua_State *L, const void* b, size_t size, void* B) {141 (void)L;142 luaL_addlstring((luaL_Buffer*) B, (const char *)b, size);143 return 0;144 }147 static int str_dump (lua_State *L) {148 luaL_Buffer b;149 luaL_checktype(L, 1, LUA_TFUNCTION);150 lua_settop(L, 1);151 luaL_buffinit(L,&b);152 if (lua_dump(L, writer, &b) != 0)153 luaL_error(L, "unable to dump given function");154 luaL_pushresult(&b);155 return 1;156 }160 /*161 ** {======================================================162 ** PATTERN MATCHING163 ** =======================================================164 */167 #define CAP_UNFINISHED (-1)168 #define CAP_POSITION (-2)170 typedef struct MatchState {171 const char *src_init; /* init of source string */172 const char *src_end; /* end (`\0') of source string */173 lua_State *L;174 int level; /* total number of captures (finished or unfinished) */175 struct {176 const char *init;177 ptrdiff_t len;178 } capture[LUA_MAXCAPTURES];179 } MatchState;182 #define L_ESC '%'183 #define SPECIALS "^$*+?.([%-"186 static int check_capture (MatchState *ms, int l) {187 l -= '1';188 if (l < 0 || l >= ms->level || ms->capture[l].len == CAP_UNFINISHED)189 return luaL_error(ms->L, "invalid capture index");190 return l;191 }194 static int capture_to_close (MatchState *ms) {195 int level = ms->level;196 for (level--; level>=0; level--)197 if (ms->capture[level].len == CAP_UNFINISHED) return level;198 return luaL_error(ms->L, "invalid pattern capture");199 }202 static const char *classend (MatchState *ms, const char *p) {203 switch (*p++) {204 case L_ESC: {205 if (*p == '\0')206 luaL_error(ms->L, "malformed pattern (ends with " LUA_QL("%%") ")");207 return p+1;208 }209 case '[': {210 if (*p == '^') p++;211 do { /* look for a `]' */212 if (*p == '\0')213 luaL_error(ms->L, "malformed pattern (missing " LUA_QL("]") ")");214 if (*(p++) == L_ESC && *p != '\0')215 p++; /* skip escapes (e.g. `%]') */216 } while (*p != ']');217 return p+1;218 }219 default: {220 return p;221 }222 }223 }226 static int match_class (int c, int cl) {227 int res;228 switch (tolower(cl)) {229 case 'a' : res = isalpha(c); break;230 case 'c' : res = iscntrl(c); break;231 case 'd' : res = isdigit(c); break;232 case 'l' : res = islower(c); break;233 case 'p' : res = ispunct(c); break;234 case 's' : res = isspace(c); break;235 case 'u' : res = isupper(c); break;236 case 'w' : res = isalnum(c); break;237 case 'x' : res = isxdigit(c); break;238 case 'z' : res = (c == 0); break;239 default: return (cl == c);240 }241 return (islower(cl) ? res : !res);242 }245 static int matchbracketclass (int c, const char *p, const char *ec) {246 int sig = 1;247 if (*(p+1) == '^') {248 sig = 0;249 p++; /* skip the `^' */250 }251 while (++p < ec) {252 if (*p == L_ESC) {253 p++;254 if (match_class(c, uchar(*p)))255 return sig;256 }257 else if ((*(p+1) == '-') && (p+2 < ec)) {258 p+=2;259 if (uchar(*(p-2)) <= c && c <= uchar(*p))260 return sig;261 }262 else if (uchar(*p) == c) return sig;263 }264 return !sig;265 }268 static int singlematch (int c, const char *p, const char *ep) {269 switch (*p) {270 case '.': return 1; /* matches any char */271 case L_ESC: return match_class(c, uchar(*(p+1)));272 case '[': return matchbracketclass(c, p, ep-1);273 default: return (uchar(*p) == c);274 }275 }278 static const char *match (MatchState *ms, const char *s, const char *p);281 static const char *matchbalance (MatchState *ms, const char *s,282 const char *p) {283 if (*p == 0 || *(p+1) == 0)284 luaL_error(ms->L, "unbalanced pattern");285 if (*s != *p) return NULL;286 else {287 int b = *p;288 int e = *(p+1);289 int cont = 1;290 while (++s < ms->src_end) {291 if (*s == e) {292 if (--cont == 0) return s+1;293 }294 else if (*s == b) cont++;295 }296 }297 return NULL; /* string ends out of balance */298 }301 static const char *max_expand (MatchState *ms, const char *s,302 const char *p, const char *ep) {303 ptrdiff_t i = 0; /* counts maximum expand for item */304 while ((s+i)<ms->src_end && singlematch(uchar(*(s+i)), p, ep))305 i++;306 /* keeps trying to match with the maximum repetitions */307 while (i>=0) {308 const char *res = match(ms, (s+i), ep+1);309 if (res) return res;310 i--; /* else didn't match; reduce 1 repetition to try again */311 }312 return NULL;313 }316 static const char *min_expand (MatchState *ms, const char *s,317 const char *p, const char *ep) {318 for (;;) {319 const char *res = match(ms, s, ep+1);320 if (res != NULL)321 return res;322 else if (s<ms->src_end && singlematch(uchar(*s), p, ep))323 s++; /* try with one more repetition */324 else return NULL;325 }326 }329 static const char *start_capture (MatchState *ms, const char *s,330 const char *p, int what) {331 const char *res;332 int level = ms->level;333 if (level >= LUA_MAXCAPTURES) luaL_error(ms->L, "too many captures");334 ms->capture[level].init = s;335 ms->capture[level].len = what;336 ms->level = level+1;337 if ((res=match(ms, s, p)) == NULL) /* match failed? */338 ms->level--; /* undo capture */339 return res;340 }343 static const char *end_capture (MatchState *ms, const char *s,344 const char *p) {345 int l = capture_to_close(ms);346 const char *res;347 ms->capture[l].len = s - ms->capture[l].init; /* close capture */348 if ((res = match(ms, s, p)) == NULL) /* match failed? */349 ms->capture[l].len = CAP_UNFINISHED; /* undo capture */350 return res;351 }354 static const char *match_capture (MatchState *ms, const char *s, int l) {355 size_t len;356 l = check_capture(ms, l);357 len = ms->capture[l].len;358 if ((size_t)(ms->src_end-s) >= len &&359 memcmp(ms->capture[l].init, s, len) == 0)360 return s+len;361 else return NULL;362 }365 static const char *match (MatchState *ms, const char *s, const char *p) {366 init: /* using goto's to optimize tail recursion */367 switch (*p) {368 case '(': { /* start capture */369 if (*(p+1) == ')') /* position capture? */370 return start_capture(ms, s, p+2, CAP_POSITION);371 else372 return start_capture(ms, s, p+1, CAP_UNFINISHED);373 }374 case ')': { /* end capture */375 return end_capture(ms, s, p+1);376 }377 case L_ESC: {378 switch (*(p+1)) {379 case 'b': { /* balanced string? */380 s = matchbalance(ms, s, p+2);381 if (s == NULL) return NULL;382 p+=4; goto init; /* else return match(ms, s, p+4); */383 }384 case 'f': { /* frontier? */385 const char *ep; char previous;386 p += 2;387 if (*p != '[')388 luaL_error(ms->L, "missing " LUA_QL("[") " after "389 LUA_QL("%%f") " in pattern");390 ep = classend(ms, p); /* points to what is next */391 previous = (s == ms->src_init) ? '\0' : *(s-1);392 if (matchbracketclass(uchar(previous), p, ep-1) ||393 !matchbracketclass(uchar(*s), p, ep-1)) return NULL;394 p=ep; goto init; /* else return match(ms, s, ep); */395 }396 default: {397 if (isdigit(uchar(*(p+1)))) { /* capture results (%0-%9)? */398 s = match_capture(ms, s, uchar(*(p+1)));399 if (s == NULL) return NULL;400 p+=2; goto init; /* else return match(ms, s, p+2) */401 }402 goto dflt; /* case default */403 }404 }405 }406 case '\0': { /* end of pattern */407 return s; /* match succeeded */408 }409 case '$': {410 if (*(p+1) == '\0') /* is the `$' the last char in pattern? */411 return (s == ms->src_end) ? s : NULL; /* check end of string */412 else goto dflt;413 }414 default: dflt: { /* it is a pattern item */415 const char *ep = classend(ms, p); /* points to what is next */416 int m = s<ms->src_end && singlematch(uchar(*s), p, ep);417 switch (*ep) {418 case '?': { /* optional */419 const char *res;420 if (m && ((res=match(ms, s+1, ep+1)) != NULL))421 return res;422 p=ep+1; goto init; /* else return match(ms, s, ep+1); */423 }424 case '*': { /* 0 or more repetitions */425 return max_expand(ms, s, p, ep);426 }427 case '+': { /* 1 or more repetitions */428 return (m ? max_expand(ms, s+1, p, ep) : NULL);429 }430 case '-': { /* 0 or more repetitions (minimum) */431 return min_expand(ms, s, p, ep);432 }433 default: {434 if (!m) return NULL;435 s++; p=ep; goto init; /* else return match(ms, s+1, ep); */436 }437 }438 }439 }440 }444 static const char *lmemfind (const char *s1, size_t l1,445 const char *s2, size_t l2) {446 if (l2 == 0) return s1; /* empty strings are everywhere */447 else if (l2 > l1) return NULL; /* avoids a negative `l1' */448 else {449 const char *init; /* to search for a `*s2' inside `s1' */450 l2--; /* 1st char will be checked by `memchr' */451 l1 = l1-l2; /* `s2' cannot be found after that */452 while (l1 > 0 && (init = (const char *)memchr(s1, *s2, l1)) != NULL) {453 init++; /* 1st char is already checked */454 if (memcmp(init, s2+1, l2) == 0)455 return init-1;456 else { /* correct `l1' and `s1' to try again */457 l1 -= init-s1;458 s1 = init;459 }460 }461 return NULL; /* not found */462 }463 }466 static void push_onecapture (MatchState *ms, int i, const char *s,467 const char *e) {468 if (i >= ms->level) {469 if (i == 0) /* ms->level == 0, too */470 lua_pushlstring(ms->L, s, e - s); /* add whole match */471 else472 luaL_error(ms->L, "invalid capture index");473 }474 else {475 ptrdiff_t l = ms->capture[i].len;476 if (l == CAP_UNFINISHED) luaL_error(ms->L, "unfinished capture");477 if (l == CAP_POSITION)478 lua_pushinteger(ms->L, ms->capture[i].init - ms->src_init + 1);479 else480 lua_pushlstring(ms->L, ms->capture[i].init, l);481 }482 }485 static int push_captures (MatchState *ms, const char *s, const char *e) {486 int i;487 int nlevels = (ms->level == 0 && s) ? 1 : ms->level;488 luaL_checkstack(ms->L, nlevels, "too many captures");489 for (i = 0; i < nlevels; i++)490 push_onecapture(ms, i, s, e);491 return nlevels; /* number of strings pushed */492 }495 static int str_find_aux (lua_State *L, int find) {496 size_t l1, l2;497 const char *s = luaL_checklstring(L, 1, &l1);498 const char *p = luaL_checklstring(L, 2, &l2);499 ptrdiff_t init = posrelat(luaL_optinteger(L, 3, 1), l1) - 1;500 if (init < 0) init = 0;501 else if ((size_t)(init) > l1) init = (ptrdiff_t)l1;502 if (find && (lua_toboolean(L, 4) || /* explicit request? */503 strpbrk(p, SPECIALS) == NULL)) { /* or no special characters? */504 /* do a plain search */505 const char *s2 = lmemfind(s+init, l1-init, p, l2);506 if (s2) {507 lua_pushinteger(L, s2-s+1);508 lua_pushinteger(L, s2-s+l2);509 return 2;510 }511 }512 else {513 MatchState ms;514 int anchor = (*p == '^') ? (p++, 1) : 0;515 const char *s1=s+init;516 ms.L = L;517 ms.src_init = s;518 ms.src_end = s+l1;519 do {520 const char *res;521 ms.level = 0;522 if ((res=match(&ms, s1, p)) != NULL) {523 if (find) {524 lua_pushinteger(L, s1-s+1); /* start */525 lua_pushinteger(L, res-s); /* end */526 return push_captures(&ms, NULL, 0) + 2;527 }528 else529 return push_captures(&ms, s1, res);530 }531 } while (s1++ < ms.src_end && !anchor);532 }533 lua_pushnil(L); /* not found */534 return 1;535 }538 static int str_find (lua_State *L) {539 return str_find_aux(L, 1);540 }543 static int str_match (lua_State *L) {544 return str_find_aux(L, 0);545 }548 static int gmatch_aux (lua_State *L) {549 MatchState ms;550 size_t ls;551 const char *s = lua_tolstring(L, lua_upvalueindex(1), &ls);552 const char *p = lua_tostring(L, lua_upvalueindex(2));553 const char *src;554 ms.L = L;555 ms.src_init = s;556 ms.src_end = s+ls;557 for (src = s + (size_t)lua_tointeger(L, lua_upvalueindex(3));558 src <= ms.src_end;559 src++) {560 const char *e;561 ms.level = 0;562 if ((e = match(&ms, src, p)) != NULL) {563 lua_Integer newstart = e-s;564 if (e == src) newstart++; /* empty match? go at least one position */565 lua_pushinteger(L, newstart);566 lua_replace(L, lua_upvalueindex(3));567 return push_captures(&ms, src, e);568 }569 }570 return 0; /* not found */571 }574 static int gmatch (lua_State *L) {575 luaL_checkstring(L, 1);576 luaL_checkstring(L, 2);577 lua_settop(L, 2);578 lua_pushinteger(L, 0);579 lua_pushcclosure(L, gmatch_aux, 3);580 return 1;581 }584 static int gfind_nodef (lua_State *L) {585 return luaL_error(L, LUA_QL("string.gfind") " was renamed to "586 LUA_QL("string.gmatch"));587 }590 static void add_s (MatchState *ms, luaL_Buffer *b, const char *s,591 const char *e) {592 size_t l, i;593 const char *news = lua_tolstring(ms->L, 3, &l);594 for (i = 0; i < l; i++) {595 if (news[i] != L_ESC)596 luaL_addchar(b, news[i]);597 else {598 i++; /* skip ESC */599 if (!isdigit(uchar(news[i])))600 luaL_addchar(b, news[i]);601 else if (news[i] == '0')602 luaL_addlstring(b, s, e - s);603 else {604 push_onecapture(ms, news[i] - '1', s, e);605 luaL_addvalue(b); /* add capture to accumulated result */606 }607 }608 }609 }612 static void add_value (MatchState *ms, luaL_Buffer *b, const char *s,613 const char *e) {614 lua_State *L = ms->L;615 switch (lua_type(L, 3)) {616 case LUA_TNUMBER:617 case LUA_TSTRING: {618 add_s(ms, b, s, e);619 return;620 }621 case LUA_TFUNCTION: {622 int n;623 lua_pushvalue(L, 3);624 n = push_captures(ms, s, e);625 lua_call(L, n, 1);626 break;627 }628 case LUA_TTABLE: {629 push_onecapture(ms, 0, s, e);630 lua_gettable(L, 3);631 break;632 }633 }634 if (!lua_toboolean(L, -1)) { /* nil or false? */635 lua_pop(L, 1);636 lua_pushlstring(L, s, e - s); /* keep original text */637 }638 else if (!lua_isstring(L, -1))639 luaL_error(L, "invalid replacement value (a %s)", luaL_typename(L, -1));640 luaL_addvalue(b); /* add result to accumulator */641 }644 static int str_gsub (lua_State *L) {645 size_t srcl;646 const char *src = luaL_checklstring(L, 1, &srcl);647 const char *p = luaL_checkstring(L, 2);648 int tr = lua_type(L, 3);649 int max_s = luaL_optint(L, 4, srcl+1);650 int anchor = (*p == '^') ? (p++, 1) : 0;651 int n = 0;652 MatchState ms;653 luaL_Buffer b;654 luaL_argcheck(L, tr == LUA_TNUMBER || tr == LUA_TSTRING ||655 tr == LUA_TFUNCTION || tr == LUA_TTABLE, 3,656 "string/function/table expected");657 luaL_buffinit(L, &b);658 ms.L = L;659 ms.src_init = src;660 ms.src_end = src+srcl;661 while (n < max_s) {662 const char *e;663 ms.level = 0;664 e = match(&ms, src, p);665 if (e) {666 n++;667 add_value(&ms, &b, src, e);668 }669 if (e && e>src) /* non empty match? */670 src = e; /* skip it */671 else if (src < ms.src_end)672 luaL_addchar(&b, *src++);673 else break;674 if (anchor) break;675 }676 luaL_addlstring(&b, src, ms.src_end-src);677 luaL_pushresult(&b);678 lua_pushinteger(L, n); /* number of substitutions */679 return 2;680 }682 /* }====================================================== */685 /* maximum size of each formatted item (> len(format('%99.99f', -1e308))) */686 #define MAX_ITEM 512687 /* valid flags in a format specification */688 #define FLAGS "-+ #0"689 /*690 ** maximum size of each format specification (such as '%-099.99d')691 ** (+10 accounts for %99.99x plus margin of error)692 */693 #define MAX_FORMAT (sizeof(FLAGS) + sizeof(LUA_INTFRMLEN) + 10)696 static void addquoted (lua_State *L, luaL_Buffer *b, int arg) {697 size_t l;698 const char *s = luaL_checklstring(L, arg, &l);699 luaL_addchar(b, '"');700 while (l--) {701 switch (*s) {702 case '"': case '\\': case '\n': {703 luaL_addchar(b, '\\');704 luaL_addchar(b, *s);705 break;706 }707 case '\r': {708 luaL_addlstring(b, "\\r", 2);709 break;710 }711 case '\0': {712 luaL_addlstring(b, "\\000", 4);713 break;714 }715 default: {716 luaL_addchar(b, *s);717 break;718 }719 }720 s++;721 }722 luaL_addchar(b, '"');723 }725 static const char *scanformat (lua_State *L, const char *strfrmt, char *form) {726 const char *p = strfrmt;727 while (*p != '\0' && strchr(FLAGS, *p) != NULL) p++; /* skip flags */728 if ((size_t)(p - strfrmt) >= sizeof(FLAGS))729 luaL_error(L, "invalid format (repeated flags)");730 if (isdigit(uchar(*p))) p++; /* skip width */731 if (isdigit(uchar(*p))) p++; /* (2 digits at most) */732 if (*p == '.') {733 p++;734 if (isdigit(uchar(*p))) p++; /* skip precision */735 if (isdigit(uchar(*p))) p++; /* (2 digits at most) */736 }737 if (isdigit(uchar(*p)))738 luaL_error(L, "invalid format (width or precision too long)");739 *(form++) = '%';740 strncpy(form, strfrmt, p - strfrmt + 1);741 form += p - strfrmt + 1;742 *form = '\0';743 return p;744 }747 static void addintlen (char *form) {748 size_t l = strlen(form);749 char spec = form[l - 1];750 strcpy(form + l - 1, LUA_INTFRMLEN);751 form[l + sizeof(LUA_INTFRMLEN) - 2] = spec;752 form[l + sizeof(LUA_INTFRMLEN) - 1] = '\0';753 }756 static int str_format (lua_State *L) {757 int arg = 1;758 size_t sfl;759 const char *strfrmt = luaL_checklstring(L, arg, &sfl);760 const char *strfrmt_end = strfrmt+sfl;761 luaL_Buffer b;762 luaL_buffinit(L, &b);763 while (strfrmt < strfrmt_end) {764 if (*strfrmt != L_ESC)765 luaL_addchar(&b, *strfrmt++);766 else if (*++strfrmt == L_ESC)767 luaL_addchar(&b, *strfrmt++); /* %% */768 else { /* format item */769 char form[MAX_FORMAT]; /* to store the format (`%...') */770 char buff[MAX_ITEM]; /* to store the formatted item */771 arg++;772 strfrmt = scanformat(L, strfrmt, form);773 switch (*strfrmt++) {774 case 'c': {775 sprintf(buff, form, (int)luaL_checknumber(L, arg));776 break;777 }778 case 'd': case 'i': {779 addintlen(form);780 sprintf(buff, form, (LUA_INTFRM_T)luaL_checknumber(L, arg));781 break;782 }783 case 'o': case 'u': case 'x': case 'X': {784 addintlen(form);785 sprintf(buff, form, (unsigned LUA_INTFRM_T)luaL_checknumber(L, arg));786 break;787 }788 case 'e': case 'E': case 'f':789 case 'g': case 'G': {790 sprintf(buff, form, (double)luaL_checknumber(L, arg));791 break;792 }793 case 'q': {794 addquoted(L, &b, arg);795 continue; /* skip the 'addsize' at the end */796 }797 case 's': {798 size_t l;799 const char *s = luaL_checklstring(L, arg, &l);800 if (!strchr(form, '.') && l >= 100) {801 /* no precision and string is too long to be formatted;802 keep original string */803 lua_pushvalue(L, arg);804 luaL_addvalue(&b);805 continue; /* skip the `addsize' at the end */806 }807 else {808 sprintf(buff, form, s);809 break;810 }811 }812 default: { /* also treat cases `pnLlh' */813 return luaL_error(L, "invalid option " LUA_QL("%%%c") " to "814 LUA_QL("format"), *(strfrmt - 1));815 }816 }817 luaL_addlstring(&b, buff, strlen(buff));818 }819 }820 luaL_pushresult(&b);821 return 1;822 }825 static const luaL_Reg strlib[] = {826 {"byte", str_byte},827 {"char", str_char},828 {"dump", str_dump},829 {"find", str_find},830 {"format", str_format},831 {"gfind", gfind_nodef},832 {"gmatch", gmatch},833 {"gsub", str_gsub},834 {"len", str_len},835 {"lower", str_lower},836 {"match", str_match},837 {"rep", str_rep},838 {"reverse", str_reverse},839 {"sub", str_sub},840 {"upper", str_upper},841 {NULL, NULL}842 };845 static void createmetatable (lua_State *L) {846 lua_createtable(L, 0, 1); /* create metatable for strings */847 lua_pushliteral(L, ""); /* dummy string */848 lua_pushvalue(L, -2);849 lua_setmetatable(L, -2); /* set string metatable */850 lua_pop(L, 1); /* pop dummy string */851 lua_pushvalue(L, -2); /* string library... */852 lua_setfield(L, -2, "__index"); /* ...is the __index metamethod */853 lua_pop(L, 1); /* pop metatable */854 }857 /*858 ** Open string library859 */860 LUALIB_API int luaopen_string (lua_State *L) {861 luaL_register(L, LUA_STRLIBNAME, strlib);862 #if defined(LUA_COMPAT_GFIND)863 lua_getfield(L, -1, "gmatch");864 lua_setfield(L, -2, "gfind");865 #endif866 createmetatable(L);867 return 1;868 }