diff options
Diffstat (limited to 'src/lib/lualib/lstrlib.c')
-rw-r--r-- | src/lib/lualib/lstrlib.c | 1582 |
1 files changed, 0 insertions, 1582 deletions
diff --git a/src/lib/lualib/lstrlib.c b/src/lib/lualib/lstrlib.c deleted file mode 100644 index 12264f8..0000000 --- a/src/lib/lualib/lstrlib.c +++ /dev/null @@ -1,1582 +0,0 @@ -/* -** $Id: lstrlib.c,v 1.251 2016/05/20 14:13:21 roberto Exp $ -** Standard library for string operations and pattern-matching -** See Copyright Notice in lua.h -*/ - -#define lstrlib_c -#define LUA_LIB - -#include "lprefix.h" - - -#include <ctype.h> -#include <float.h> -#include <limits.h> -#include <locale.h> -#include <stddef.h> -#include <stdio.h> -#include <stdlib.h> -#include <string.h> - -#include "lua.h" - -#include "lauxlib.h" -#include "lualib.h" - - -/* -** maximum number of captures that a pattern can do during -** pattern-matching. This limit is arbitrary, but must fit in -** an unsigned char. -*/ -#if !defined(LUA_MAXCAPTURES) -#define LUA_MAXCAPTURES 32 -#endif - - -/* macro to 'unsign' a character */ -#define uchar(c) ((unsigned char)(c)) - - -/* -** Some sizes are better limited to fit in 'int', but must also fit in -** 'size_t'. (We assume that 'lua_Integer' cannot be smaller than 'int'.) -*/ -#define MAX_SIZET ((size_t)(~(size_t)0)) - -#define MAXSIZE \ - (sizeof(size_t) < sizeof(int) ? MAX_SIZET : (size_t)(INT_MAX)) - - - - -static int str_len (lua_State *L) { - size_t l; - luaL_checklstring(L, 1, &l); - lua_pushinteger(L, (lua_Integer)l); - return 1; -} - - -/* translate a relative string position: negative means back from end */ -static lua_Integer posrelat (lua_Integer pos, size_t len) { - if (pos >= 0) return pos; - else if (0u - (size_t)pos > len) return 0; - else return (lua_Integer)len + pos + 1; -} - - -static int str_sub (lua_State *L) { - size_t l; - const char *s = luaL_checklstring(L, 1, &l); - lua_Integer start = posrelat(luaL_checkinteger(L, 2), l); - lua_Integer end = posrelat(luaL_optinteger(L, 3, -1), l); - if (start < 1) start = 1; - if (end > (lua_Integer)l) end = l; - if (start <= end) - lua_pushlstring(L, s + start - 1, (size_t)(end - start) + 1); - else lua_pushliteral(L, ""); - return 1; -} - - -static int str_reverse (lua_State *L) { - size_t l, i; - luaL_Buffer b; - const char *s = luaL_checklstring(L, 1, &l); - char *p = luaL_buffinitsize(L, &b, l); - for (i = 0; i < l; i++) - p[i] = s[l - i - 1]; - luaL_pushresultsize(&b, l); - return 1; -} - - -static int str_lower (lua_State *L) { - size_t l; - size_t i; - luaL_Buffer b; - const char *s = luaL_checklstring(L, 1, &l); - char *p = luaL_buffinitsize(L, &b, l); - for (i=0; i<l; i++) - p[i] = tolower(uchar(s[i])); - luaL_pushresultsize(&b, l); - return 1; -} - - -static int str_upper (lua_State *L) { - size_t l; - size_t i; - luaL_Buffer b; - const char *s = luaL_checklstring(L, 1, &l); - char *p = luaL_buffinitsize(L, &b, l); - for (i=0; i<l; i++) - p[i] = toupper(uchar(s[i])); - luaL_pushresultsize(&b, l); - return 1; -} - - -static int str_rep (lua_State *L) { - size_t l, lsep; - const char *s = luaL_checklstring(L, 1, &l); - lua_Integer n = luaL_checkinteger(L, 2); - const char *sep = luaL_optlstring(L, 3, "", &lsep); - if (n <= 0) lua_pushliteral(L, ""); - else if (l + lsep < l || l + lsep > MAXSIZE / n) /* may overflow? */ - return luaL_error(L, "resulting string too large"); - else { - size_t totallen = (size_t)n * l + (size_t)(n - 1) * lsep; - luaL_Buffer b; - char *p = luaL_buffinitsize(L, &b, totallen); - while (n-- > 1) { /* first n-1 copies (followed by separator) */ - memcpy(p, s, l * sizeof(char)); p += l; - if (lsep > 0) { /* empty 'memcpy' is not that cheap */ - memcpy(p, sep, lsep * sizeof(char)); - p += lsep; - } - } - memcpy(p, s, l * sizeof(char)); /* last copy (not followed by separator) */ - luaL_pushresultsize(&b, totallen); - } - return 1; -} - - -static int str_byte (lua_State *L) { - size_t l; - const char *s = luaL_checklstring(L, 1, &l); - lua_Integer posi = posrelat(luaL_optinteger(L, 2, 1), l); - lua_Integer pose = posrelat(luaL_optinteger(L, 3, posi), l); - int n, i; - if (posi < 1) posi = 1; - if (pose > (lua_Integer)l) pose = l; - if (posi > pose) return 0; /* empty interval; return no values */ - if (pose - posi >= INT_MAX) /* arithmetic overflow? */ - return luaL_error(L, "string slice too long"); - n = (int)(pose - posi) + 1; - luaL_checkstack(L, n, "string slice too long"); - for (i=0; i<n; i++) - lua_pushinteger(L, uchar(s[posi+i-1])); - return n; -} - - -static int str_char (lua_State *L) { - int n = lua_gettop(L); /* number of arguments */ - int i; - luaL_Buffer b; - char *p = luaL_buffinitsize(L, &b, n); - for (i=1; i<=n; i++) { - lua_Integer c = luaL_checkinteger(L, i); - luaL_argcheck(L, uchar(c) == c, i, "value out of range"); - p[i - 1] = uchar(c); - } - luaL_pushresultsize(&b, n); - return 1; -} - - -static int writer (lua_State *L, const void *b, size_t size, void *B) { - (void)L; - luaL_addlstring((luaL_Buffer *) B, (const char *)b, size); - return 0; -} - - -static int str_dump (lua_State *L) { - luaL_Buffer b; - int strip = lua_toboolean(L, 2); - luaL_checktype(L, 1, LUA_TFUNCTION); - lua_settop(L, 1); - luaL_buffinit(L,&b); - if (lua_dump(L, writer, &b, strip) != 0) - return luaL_error(L, "unable to dump given function"); - luaL_pushresult(&b); - return 1; -} - - - -/* -** {====================================================== -** PATTERN MATCHING -** ======================================================= -*/ - - -#define CAP_UNFINISHED (-1) -#define CAP_POSITION (-2) - - -typedef struct MatchState { - const char *src_init; /* init of source string */ - const char *src_end; /* end ('\0') of source string */ - const char *p_end; /* end ('\0') of pattern */ - lua_State *L; - int matchdepth; /* control for recursive depth (to avoid C stack overflow) */ - unsigned char level; /* total number of captures (finished or unfinished) */ - struct { - const char *init; - ptrdiff_t len; - } capture[LUA_MAXCAPTURES]; -} MatchState; - - -/* recursive function */ -static const char *match (MatchState *ms, const char *s, const char *p); - - -/* maximum recursion depth for 'match' */ -#if !defined(MAXCCALLS) -#define MAXCCALLS 200 -#endif - - -#define L_ESC '%' -#define SPECIALS "^$*+?.([%-" - - -static int check_capture (MatchState *ms, int l) { - l -= '1'; - if (l < 0 || l >= ms->level || ms->capture[l].len == CAP_UNFINISHED) - return luaL_error(ms->L, "invalid capture index %%%d", l + 1); - return l; -} - - -static int capture_to_close (MatchState *ms) { - int level = ms->level; - for (level--; level>=0; level--) - if (ms->capture[level].len == CAP_UNFINISHED) return level; - return luaL_error(ms->L, "invalid pattern capture"); -} - - -static const char *classend (MatchState *ms, const char *p) { - switch (*p++) { - case L_ESC: { - if (p == ms->p_end) - luaL_error(ms->L, "malformed pattern (ends with '%%')"); - return p+1; - } - case '[': { - if (*p == '^') p++; - do { /* look for a ']' */ - if (p == ms->p_end) - luaL_error(ms->L, "malformed pattern (missing ']')"); - if (*(p++) == L_ESC && p < ms->p_end) - p++; /* skip escapes (e.g. '%]') */ - } while (*p != ']'); - return p+1; - } - default: { - return p; - } - } -} - - -static int match_class (int c, int cl) { - int res; - switch (tolower(cl)) { - case 'a' : res = isalpha(c); break; - case 'c' : res = iscntrl(c); break; - case 'd' : res = isdigit(c); break; - case 'g' : res = isgraph(c); break; - case 'l' : res = islower(c); break; - case 'p' : res = ispunct(c); break; - case 's' : res = isspace(c); break; - case 'u' : res = isupper(c); break; - case 'w' : res = isalnum(c); break; - case 'x' : res = isxdigit(c); break; - case 'z' : res = (c == 0); break; /* deprecated option */ - default: return (cl == c); - } - return (islower(cl) ? res : !res); -} - - -static int matchbracketclass (int c, const char *p, const char *ec) { - int sig = 1; - if (*(p+1) == '^') { - sig = 0; - p++; /* skip the '^' */ - } - while (++p < ec) { - if (*p == L_ESC) { - p++; - if (match_class(c, uchar(*p))) - return sig; - } - else if ((*(p+1) == '-') && (p+2 < ec)) { - p+=2; - if (uchar(*(p-2)) <= c && c <= uchar(*p)) - return sig; - } - else if (uchar(*p) == c) return sig; - } - return !sig; -} - - -static int singlematch (MatchState *ms, const char *s, const char *p, - const char *ep) { - if (s >= ms->src_end) - return 0; - else { - int c = uchar(*s); - switch (*p) { - case '.': return 1; /* matches any char */ - case L_ESC: return match_class(c, uchar(*(p+1))); - case '[': return matchbracketclass(c, p, ep-1); - default: return (uchar(*p) == c); - } - } -} - - -static const char *matchbalance (MatchState *ms, const char *s, - const char *p) { - if (p >= ms->p_end - 1) - luaL_error(ms->L, "malformed pattern (missing arguments to '%%b')"); - if (*s != *p) return NULL; - else { - int b = *p; - int e = *(p+1); - int cont = 1; - while (++s < ms->src_end) { - if (*s == e) { - if (--cont == 0) return s+1; - } - else if (*s == b) cont++; - } - } - return NULL; /* string ends out of balance */ -} - - -static const char *max_expand (MatchState *ms, const char *s, - const char *p, const char *ep) { - ptrdiff_t i = 0; /* counts maximum expand for item */ - while (singlematch(ms, s + i, p, ep)) - i++; - /* keeps trying to match with the maximum repetitions */ - while (i>=0) { - const char *res = match(ms, (s+i), ep+1); - if (res) return res; - i--; /* else didn't match; reduce 1 repetition to try again */ - } - return NULL; -} - - -static const char *min_expand (MatchState *ms, const char *s, - const char *p, const char *ep) { - for (;;) { - const char *res = match(ms, s, ep+1); - if (res != NULL) - return res; - else if (singlematch(ms, s, p, ep)) - s++; /* try with one more repetition */ - else return NULL; - } -} - - -static const char *start_capture (MatchState *ms, const char *s, - const char *p, int what) { - const char *res; - int level = ms->level; - if (level >= LUA_MAXCAPTURES) luaL_error(ms->L, "too many captures"); - ms->capture[level].init = s; - ms->capture[level].len = what; - ms->level = level+1; - if ((res=match(ms, s, p)) == NULL) /* match failed? */ - ms->level--; /* undo capture */ - return res; -} - - -static const char *end_capture (MatchState *ms, const char *s, - const char *p) { - int l = capture_to_close(ms); - const char *res; - ms->capture[l].len = s - ms->capture[l].init; /* close capture */ - if ((res = match(ms, s, p)) == NULL) /* match failed? */ - ms->capture[l].len = CAP_UNFINISHED; /* undo capture */ - return res; -} - - -static const char *match_capture (MatchState *ms, const char *s, int l) { - size_t len; - l = check_capture(ms, l); - len = ms->capture[l].len; - if ((size_t)(ms->src_end-s) >= len && - memcmp(ms->capture[l].init, s, len) == 0) - return s+len; - else return NULL; -} - - -static const char *match (MatchState *ms, const char *s, const char *p) { - if (ms->matchdepth-- == 0) - luaL_error(ms->L, "pattern too complex"); - init: /* using goto's to optimize tail recursion */ - if (p != ms->p_end) { /* end of pattern? */ - switch (*p) { - case '(': { /* start capture */ - if (*(p + 1) == ')') /* position capture? */ - s = start_capture(ms, s, p + 2, CAP_POSITION); - else - s = start_capture(ms, s, p + 1, CAP_UNFINISHED); - break; - } - case ')': { /* end capture */ - s = end_capture(ms, s, p + 1); - break; - } - case '$': { - if ((p + 1) != ms->p_end) /* is the '$' the last char in pattern? */ - goto dflt; /* no; go to default */ - s = (s == ms->src_end) ? s : NULL; /* check end of string */ - break; - } - case L_ESC: { /* escaped sequences not in the format class[*+?-]? */ - switch (*(p + 1)) { - case 'b': { /* balanced string? */ - s = matchbalance(ms, s, p + 2); - if (s != NULL) { - p += 4; goto init; /* return match(ms, s, p + 4); */ - } /* else fail (s == NULL) */ - break; - } - case 'f': { /* frontier? */ - const char *ep; char previous; - p += 2; - if (*p != '[') - luaL_error(ms->L, "missing '[' after '%%f' in pattern"); - ep = classend(ms, p); /* points to what is next */ - previous = (s == ms->src_init) ? '\0' : *(s - 1); - if (!matchbracketclass(uchar(previous), p, ep - 1) && - matchbracketclass(uchar(*s), p, ep - 1)) { - p = ep; goto init; /* return match(ms, s, ep); */ - } - s = NULL; /* match failed */ - break; - } - case '0': case '1': case '2': case '3': - case '4': case '5': case '6': case '7': - case '8': case '9': { /* capture results (%0-%9)? */ - s = match_capture(ms, s, uchar(*(p + 1))); - if (s != NULL) { - p += 2; goto init; /* return match(ms, s, p + 2) */ - } - break; - } - default: goto dflt; - } - break; - } - default: dflt: { /* pattern class plus optional suffix */ - const char *ep = classend(ms, p); /* points to optional suffix */ - /* does not match at least once? */ - if (!singlematch(ms, s, p, ep)) { - if (*ep == '*' || *ep == '?' || *ep == '-') { /* accept empty? */ - p = ep + 1; goto init; /* return match(ms, s, ep + 1); */ - } - else /* '+' or no suffix */ - s = NULL; /* fail */ - } - else { /* matched once */ - switch (*ep) { /* handle optional suffix */ - case '?': { /* optional */ - const char *res; - if ((res = match(ms, s + 1, ep + 1)) != NULL) - s = res; - else { - p = ep + 1; goto init; /* else return match(ms, s, ep + 1); */ - } - break; - } - case '+': /* 1 or more repetitions */ - s++; /* 1 match already done */ - /* FALLTHROUGH */ - case '*': /* 0 or more repetitions */ - s = max_expand(ms, s, p, ep); - break; - case '-': /* 0 or more repetitions (minimum) */ - s = min_expand(ms, s, p, ep); - break; - default: /* no suffix */ - s++; p = ep; goto init; /* return match(ms, s + 1, ep); */ - } - } - break; - } - } - } - ms->matchdepth++; - return s; -} - - - -static const char *lmemfind (const char *s1, size_t l1, - const char *s2, size_t l2) { - if (l2 == 0) return s1; /* empty strings are everywhere */ - else if (l2 > l1) return NULL; /* avoids a negative 'l1' */ - else { - const char *init; /* to search for a '*s2' inside 's1' */ - l2--; /* 1st char will be checked by 'memchr' */ - l1 = l1-l2; /* 's2' cannot be found after that */ - while (l1 > 0 && (init = (const char *)memchr(s1, *s2, l1)) != NULL) { - init++; /* 1st char is already checked */ - if (memcmp(init, s2+1, l2) == 0) - return init-1; - else { /* correct 'l1' and 's1' to try again */ - l1 -= init-s1; - s1 = init; - } - } - return NULL; /* not found */ - } -} - - -static void push_onecapture (MatchState *ms, int i, const char *s, - const char *e) { - if (i >= ms->level) { - if (i == 0) /* ms->level == 0, too */ - lua_pushlstring(ms->L, s, e - s); /* add whole match */ - else - luaL_error(ms->L, "invalid capture index %%%d", i + 1); - } - else { - ptrdiff_t l = ms->capture[i].len; - if (l == CAP_UNFINISHED) luaL_error(ms->L, "unfinished capture"); - if (l == CAP_POSITION) - lua_pushinteger(ms->L, (ms->capture[i].init - ms->src_init) + 1); - else - lua_pushlstring(ms->L, ms->capture[i].init, l); - } -} - - -static int push_captures (MatchState *ms, const char *s, const char *e) { - int i; - int nlevels = (ms->level == 0 && s) ? 1 : ms->level; - luaL_checkstack(ms->L, nlevels, "too many captures"); - for (i = 0; i < nlevels; i++) - push_onecapture(ms, i, s, e); - return nlevels; /* number of strings pushed */ -} - - -/* check whether pattern has no special characters */ -static int nospecials (const char *p, size_t l) { - size_t upto = 0; - do { - if (strpbrk(p + upto, SPECIALS)) - return 0; /* pattern has a special character */ - upto += strlen(p + upto) + 1; /* may have more after \0 */ - } while (upto <= l); - return 1; /* no special chars found */ -} - - -static void prepstate (MatchState *ms, lua_State *L, - const char *s, size_t ls, const char *p, size_t lp) { - ms->L = L; - ms->matchdepth = MAXCCALLS; - ms->src_init = s; - ms->src_end = s + ls; - ms->p_end = p + lp; -} - - -static void reprepstate (MatchState *ms) { - ms->level = 0; - lua_assert(ms->matchdepth == MAXCCALLS); -} - - -static int str_find_aux (lua_State *L, int find) { - size_t ls, lp; - const char *s = luaL_checklstring(L, 1, &ls); - const char *p = luaL_checklstring(L, 2, &lp); - lua_Integer init = posrelat(luaL_optinteger(L, 3, 1), ls); - if (init < 1) init = 1; - else if (init > (lua_Integer)ls + 1) { /* start after string's end? */ - lua_pushnil(L); /* cannot find anything */ - return 1; - } - /* explicit request or no special characters? */ - if (find && (lua_toboolean(L, 4) || nospecials(p, lp))) { - /* do a plain search */ - const char *s2 = lmemfind(s + init - 1, ls - (size_t)init + 1, p, lp); - if (s2) { - lua_pushinteger(L, (s2 - s) + 1); - lua_pushinteger(L, (s2 - s) + lp); - return 2; - } - } - else { - MatchState ms; - const char *s1 = s + init - 1; - int anchor = (*p == '^'); - if (anchor) { - p++; lp--; /* skip anchor character */ - } - prepstate(&ms, L, s, ls, p, lp); - do { - const char *res; - reprepstate(&ms); - if ((res=match(&ms, s1, p)) != NULL) { - if (find) { - lua_pushinteger(L, (s1 - s) + 1); /* start */ - lua_pushinteger(L, res - s); /* end */ - return push_captures(&ms, NULL, 0) + 2; - } - else - return push_captures(&ms, s1, res); - } - } while (s1++ < ms.src_end && !anchor); - } - lua_pushnil(L); /* not found */ - return 1; -} - - -static int str_find (lua_State *L) { - return str_find_aux(L, 1); -} - - -static int str_match (lua_State *L) { - return str_find_aux(L, 0); -} - - -/* state for 'gmatch' */ -typedef struct GMatchState { - const char *src; /* current position */ - const char *p; /* pattern */ - const char *lastmatch; /* end of last match */ - MatchState ms; /* match state */ -} GMatchState; - - -static int gmatch_aux (lua_State *L) { - GMatchState *gm = (GMatchState *)lua_touserdata(L, lua_upvalueindex(3)); - const char *src; - gm->ms.L = L; - for (src = gm->src; src <= gm->ms.src_end; src++) { - const char *e; - reprepstate(&gm->ms); - if ((e = match(&gm->ms, src, gm->p)) != NULL && e != gm->lastmatch) { - gm->src = gm->lastmatch = e; - return push_captures(&gm->ms, src, e); - } - } - return 0; /* not found */ -} - - -static int gmatch (lua_State *L) { - size_t ls, lp; - const char *s = luaL_checklstring(L, 1, &ls); - const char *p = luaL_checklstring(L, 2, &lp); - GMatchState *gm; - lua_settop(L, 2); /* keep them on closure to avoid being collected */ - gm = (GMatchState *)lua_newuserdata(L, sizeof(GMatchState)); - prepstate(&gm->ms, L, s, ls, p, lp); - gm->src = s; gm->p = p; gm->lastmatch = NULL; - lua_pushcclosure(L, gmatch_aux, 3); - return 1; -} - - -static void add_s (MatchState *ms, luaL_Buffer *b, const char *s, - const char *e) { - size_t l, i; - lua_State *L = ms->L; - const char *news = lua_tolstring(L, 3, &l); - for (i = 0; i < l; i++) { - if (news[i] != L_ESC) - luaL_addchar(b, news[i]); - else { - i++; /* skip ESC */ - if (!isdigit(uchar(news[i]))) { - if (news[i] != L_ESC) - luaL_error(L, "invalid use of '%c' in replacement string", L_ESC); - luaL_addchar(b, news[i]); - } - else if (news[i] == '0') - luaL_addlstring(b, s, e - s); - else { - push_onecapture(ms, news[i] - '1', s, e); - luaL_tolstring(L, -1, NULL); /* if number, convert it to string */ - lua_remove(L, -2); /* remove original value */ - luaL_addvalue(b); /* add capture to accumulated result */ - } - } - } -} - - -static void add_value (MatchState *ms, luaL_Buffer *b, const char *s, - const char *e, int tr) { - lua_State *L = ms->L; - switch (tr) { - case LUA_TFUNCTION: { - int n; - lua_pushvalue(L, 3); - n = push_captures(ms, s, e); - lua_call(L, n, 1); - break; - } - case LUA_TTABLE: { - push_onecapture(ms, 0, s, e); - lua_gettable(L, 3); - break; - } - default: { /* LUA_TNUMBER or LUA_TSTRING */ - add_s(ms, b, s, e); - return; - } - } - if (!lua_toboolean(L, -1)) { /* nil or false? */ - lua_pop(L, 1); - lua_pushlstring(L, s, e - s); /* keep original text */ - } - else if (!lua_isstring(L, -1)) - luaL_error(L, "invalid replacement value (a %s)", luaL_typename(L, -1)); - luaL_addvalue(b); /* add result to accumulator */ -} - - -static int str_gsub (lua_State *L) { - size_t srcl, lp; - const char *src = luaL_checklstring(L, 1, &srcl); /* subject */ - const char *p = luaL_checklstring(L, 2, &lp); /* pattern */ - const char *lastmatch = NULL; /* end of last match */ - int tr = lua_type(L, 3); /* replacement type */ - lua_Integer max_s = luaL_optinteger(L, 4, srcl + 1); /* max replacements */ - int anchor = (*p == '^'); - lua_Integer n = 0; /* replacement count */ - MatchState ms; - luaL_Buffer b; - luaL_argcheck(L, tr == LUA_TNUMBER || tr == LUA_TSTRING || - tr == LUA_TFUNCTION || tr == LUA_TTABLE, 3, - "string/function/table expected"); - luaL_buffinit(L, &b); - if (anchor) { - p++; lp--; /* skip anchor character */ - } - prepstate(&ms, L, src, srcl, p, lp); - while (n < max_s) { - const char *e; - reprepstate(&ms); /* (re)prepare state for new match */ - if ((e = match(&ms, src, p)) != NULL && e != lastmatch) { /* match? */ - n++; - add_value(&ms, &b, src, e, tr); /* add replacement to buffer */ - src = lastmatch = e; - } - else if (src < ms.src_end) /* otherwise, skip one character */ - luaL_addchar(&b, *src++); - else break; /* end of subject */ - if (anchor) break; - } - luaL_addlstring(&b, src, ms.src_end-src); - luaL_pushresult(&b); - lua_pushinteger(L, n); /* number of substitutions */ - return 2; -} - -/* }====================================================== */ - - - -/* -** {====================================================== -** STRING FORMAT -** ======================================================= -*/ - -#if !defined(lua_number2strx) /* { */ - -/* -** Hexadecimal floating-point formatter -*/ - -#include <math.h> - -#define SIZELENMOD (sizeof(LUA_NUMBER_FRMLEN)/sizeof(char)) - - -/* -** Number of bits that goes into the first digit. It can be any value -** between 1 and 4; the following definition tries to align the number -** to nibble boundaries by making what is left after that first digit a -** multiple of 4. -*/ -#define L_NBFD ((l_mathlim(MANT_DIG) - 1)%4 + 1) - - -/* -** Add integer part of 'x' to buffer and return new 'x' -*/ -static lua_Number adddigit (char *buff, int n, lua_Number x) { - lua_Number dd = l_mathop(floor)(x); /* get integer part from 'x' */ - int d = (int)dd; - buff[n] = (d < 10 ? d + '0' : d - 10 + 'a'); /* add to buffer */ - return x - dd; /* return what is left */ -} - - -static int num2straux (char *buff, int sz, lua_Number x) { - if (x != x || x == HUGE_VAL || x == -HUGE_VAL) /* inf or NaN? */ - return l_sprintf(buff, sz, LUA_NUMBER_FMT, x); /* equal to '%g' */ - else if (x == 0) { /* can be -0... */ - /* create "0" or "-0" followed by exponent */ - return l_sprintf(buff, sz, LUA_NUMBER_FMT "x0p+0", x); - } - else { - int e; - lua_Number m = l_mathop(frexp)(x, &e); /* 'x' fraction and exponent */ - int n = 0; /* character count */ - if (m < 0) { /* is number negative? */ - buff[n++] = '-'; /* add signal */ - m = -m; /* make it positive */ - } - buff[n++] = '0'; buff[n++] = 'x'; /* add "0x" */ - m = adddigit(buff, n++, m * (1 << L_NBFD)); /* add first digit */ - e -= L_NBFD; /* this digit goes before the radix point */ - if (m > 0) { /* more digits? */ - buff[n++] = lua_getlocaledecpoint(); /* add radix point */ - do { /* add as many digits as needed */ - m = adddigit(buff, n++, m * 16); - } while (m > 0); - } - n += l_sprintf(buff + n, sz - n, "p%+d", e); /* add exponent */ - lua_assert(n < sz); - return n; - } -} - - -static int lua_number2strx (lua_State *L, char *buff, int sz, - const char *fmt, lua_Number x) { - int n = num2straux(buff, sz, x); - if (fmt[SIZELENMOD] == 'A') { - int i; - for (i = 0; i < n; i++) - buff[i] = toupper(uchar(buff[i])); - } - else if (fmt[SIZELENMOD] != 'a') - luaL_error(L, "modifiers for format '%%a'/'%%A' not implemented"); - return n; -} - -#endif /* } */ - - -/* -** Maximum size of each formatted item. This maximum size is produced -** by format('%.99f', -maxfloat), and is equal to 99 + 3 ('-', '.', -** and '\0') + number of decimal digits to represent maxfloat (which -** is maximum exponent + 1). (99+3+1 then rounded to 120 for "extra -** expenses", such as locale-dependent stuff) -*/ -#define MAX_ITEM (120 + l_mathlim(MAX_10_EXP)) - - -/* valid flags in a format specification */ -#define FLAGS "-+ #0" - -/* -** maximum size of each format specification (such as "%-099.99d") -*/ -#define MAX_FORMAT 32 - - -static void addquoted (luaL_Buffer *b, const char *s, size_t len) { - luaL_addchar(b, '"'); - while (len--) { - if (*s == '"' || *s == '\\' || *s == '\n') { - luaL_addchar(b, '\\'); - luaL_addchar(b, *s); - } - else if (iscntrl(uchar(*s))) { - char buff[10]; - if (!isdigit(uchar(*(s+1)))) - l_sprintf(buff, sizeof(buff), "\\%d", (int)uchar(*s)); - else - l_sprintf(buff, sizeof(buff), "\\%03d", (int)uchar(*s)); - luaL_addstring(b, buff); - } - else - luaL_addchar(b, *s); - s++; - } - luaL_addchar(b, '"'); -} - - -/* -** Ensures the 'buff' string uses a dot as the radix character. -*/ -static void checkdp (char *buff, int nb) { - if (memchr(buff, '.', nb) == NULL) { /* no dot? */ - char point = lua_getlocaledecpoint(); /* try locale point */ - char *ppoint = memchr(buff, point, nb); - if (ppoint) *ppoint = '.'; /* change it to a dot */ - } -} - - -static void addliteral (lua_State *L, luaL_Buffer *b, int arg) { - switch (lua_type(L, arg)) { - case LUA_TSTRING: { - size_t len; - const char *s = lua_tolstring(L, arg, &len); - addquoted(b, s, len); - break; - } - case LUA_TNUMBER: { - char *buff = luaL_prepbuffsize(b, MAX_ITEM); - int nb; - if (!lua_isinteger(L, arg)) { /* float? */ - lua_Number n = lua_tonumber(L, arg); /* write as hexa ('%a') */ - nb = lua_number2strx(L, buff, MAX_ITEM, "%" LUA_NUMBER_FRMLEN "a", n); - checkdp(buff, nb); /* ensure it uses a dot */ - } - else { /* integers */ - lua_Integer n = lua_tointeger(L, arg); - const char *format = (n == LUA_MININTEGER) /* corner case? */ - ? "0x%" LUA_INTEGER_FRMLEN "x" /* use hexa */ - : LUA_INTEGER_FMT; /* else use default format */ - nb = l_sprintf(buff, MAX_ITEM, format, n); - } - luaL_addsize(b, nb); - break; - } - case LUA_TNIL: case LUA_TBOOLEAN: { - luaL_tolstring(L, arg, NULL); - luaL_addvalue(b); - break; - } - default: { - luaL_argerror(L, arg, "value has no literal form"); - } - } -} - - -static const char *scanformat (lua_State *L, const char *strfrmt, char *form) { - const char *p = strfrmt; - while (*p != '\0' && strchr(FLAGS, *p) != NULL) p++; /* skip flags */ - if ((size_t)(p - strfrmt) >= sizeof(FLAGS)/sizeof(char)) - luaL_error(L, "invalid format (repeated flags)"); - if (isdigit(uchar(*p))) p++; /* skip width */ - if (isdigit(uchar(*p))) p++; /* (2 digits at most) */ - if (*p == '.') { - p++; - if (isdigit(uchar(*p))) p++; /* skip precision */ - if (isdigit(uchar(*p))) p++; /* (2 digits at most) */ - } - if (isdigit(uchar(*p))) - luaL_error(L, "invalid format (width or precision too long)"); - *(form++) = '%'; - memcpy(form, strfrmt, ((p - strfrmt) + 1) * sizeof(char)); - form += (p - strfrmt) + 1; - *form = '\0'; - return p; -} - - -/* -** add length modifier into formats -*/ -static void addlenmod (char *form, const char *lenmod) { - size_t l = strlen(form); - size_t lm = strlen(lenmod); - char spec = form[l - 1]; - strcpy(form + l - 1, lenmod); - form[l + lm - 1] = spec; - form[l + lm] = '\0'; -} - - -static int str_format (lua_State *L) { - int top = lua_gettop(L); - int arg = 1; - size_t sfl; - const char *strfrmt = luaL_checklstring(L, arg, &sfl); - const char *strfrmt_end = strfrmt+sfl; - luaL_Buffer b; - luaL_buffinit(L, &b); - while (strfrmt < strfrmt_end) { - if (*strfrmt != L_ESC) - luaL_addchar(&b, *strfrmt++); - else if (*++strfrmt == L_ESC) - luaL_addchar(&b, *strfrmt++); /* %% */ - else { /* format item */ - char form[MAX_FORMAT]; /* to store the format ('%...') */ - char *buff = luaL_prepbuffsize(&b, MAX_ITEM); /* to put formatted item */ - int nb = 0; /* number of bytes in added item */ - if (++arg > top) - luaL_argerror(L, arg, "no value"); - strfrmt = scanformat(L, strfrmt, form); - switch (*strfrmt++) { - case 'c': { - nb = l_sprintf(buff, MAX_ITEM, form, (int)luaL_checkinteger(L, arg)); - break; - } - case 'd': case 'i': - case 'o': case 'u': case 'x': case 'X': { - lua_Integer n = luaL_checkinteger(L, arg); - addlenmod(form, LUA_INTEGER_FRMLEN); - nb = l_sprintf(buff, MAX_ITEM, form, n); - break; - } - case 'a': case 'A': - addlenmod(form, LUA_NUMBER_FRMLEN); - nb = lua_number2strx(L, buff, MAX_ITEM, form, - luaL_checknumber(L, arg)); - break; - case 'e': case 'E': case 'f': - case 'g': case 'G': { - addlenmod(form, LUA_NUMBER_FRMLEN); - nb = l_sprintf(buff, MAX_ITEM, form, luaL_checknumber(L, arg)); - break; - } - case 'q': { - addliteral(L, &b, arg); - break; - } - case 's': { - size_t l; - const char *s = luaL_tolstring(L, arg, &l); - if (form[2] == '\0') /* no modifiers? */ - luaL_addvalue(&b); /* keep entire string */ - else { - luaL_argcheck(L, l == strlen(s), arg, "string contains zeros"); - if (!strchr(form, '.') && l >= 100) { - /* no precision and string is too long to be formatted */ - luaL_addvalue(&b); /* keep entire string */ - } - else { /* format the string into 'buff' */ - nb = l_sprintf(buff, MAX_ITEM, form, s); - lua_pop(L, 1); /* remove result from 'luaL_tolstring' */ - } - } - break; - } - default: { /* also treat cases 'pnLlh' */ - return luaL_error(L, "invalid option '%%%c' to 'format'", - *(strfrmt - 1)); - } - } - lua_assert(nb < MAX_ITEM); - luaL_addsize(&b, nb); - } - } - luaL_pushresult(&b); - return 1; -} - -/* }====================================================== */ - - -/* -** {====================================================== -** PACK/UNPACK -** ======================================================= -*/ - - -/* value used for padding */ -#if !defined(LUAL_PACKPADBYTE) -#define LUAL_PACKPADBYTE 0x00 -#endif - -/* maximum size for the binary representation of an integer */ -#define MAXINTSIZE 16 - -/* number of bits in a character */ -#define NB CHAR_BIT - -/* mask for one character (NB 1's) */ -#define MC ((1 << NB) - 1) - -/* size of a lua_Integer */ -#define SZINT ((int)sizeof(lua_Integer)) - - -/* dummy union to get native endianness */ -static const union { - int dummy; - char little; /* true iff machine is little endian */ -} nativeendian = {1}; - - -/* dummy structure to get native alignment requirements */ -struct cD { - char c; - union { double d; void *p; lua_Integer i; lua_Number n; } u; -}; - -#define MAXALIGN (offsetof(struct cD, u)) - - -/* -** Union for serializing floats -*/ -typedef union Ftypes { - float f; - double d; - lua_Number n; - char buff[5 * sizeof(lua_Number)]; /* enough for any float type */ -} Ftypes; - - -/* -** information to pack/unpack stuff -*/ -typedef struct Header { - lua_State *L; - int islittle; - int maxalign; -} Header; - - -/* -** options for pack/unpack -*/ -typedef enum KOption { - Kint, /* signed integers */ - Kuint, /* unsigned integers */ - Kfloat, /* floating-point numbers */ - Kchar, /* fixed-length strings */ - Kstring, /* strings with prefixed length */ - Kzstr, /* zero-terminated strings */ - Kpadding, /* padding */ - Kpaddalign, /* padding for alignment */ - Knop /* no-op (configuration or spaces) */ -} KOption; - - -/* -** Read an integer numeral from string 'fmt' or return 'df' if -** there is no numeral -*/ -static int digit (int c) { return '0' <= c && c <= '9'; } - -static int getnum (const char **fmt, int df) { - if (!digit(**fmt)) /* no number? */ - return df; /* return default value */ - else { - int a = 0; - do { - a = a*10 + (*((*fmt)++) - '0'); - } while (digit(**fmt) && a <= ((int)MAXSIZE - 9)/10); - return a; - } -} - - -/* -** Read an integer numeral and raises an error if it is larger -** than the maximum size for integers. -*/ -static int getnumlimit (Header *h, const char **fmt, int df) { - int sz = getnum(fmt, df); - if (sz > MAXINTSIZE || sz <= 0) - luaL_error(h->L, "integral size (%d) out of limits [1,%d]", - sz, MAXINTSIZE); - return sz; -} - - -/* -** Initialize Header -*/ -static void initheader (lua_State *L, Header *h) { - h->L = L; - h->islittle = nativeendian.little; - h->maxalign = 1; -} - - -/* -** Read and classify next option. 'size' is filled with option's size. -*/ -static KOption getoption (Header *h, const char **fmt, int *size) { - int opt = *((*fmt)++); - *size = 0; /* default */ - switch (opt) { - case 'b': *size = sizeof(char); return Kint; - case 'B': *size = sizeof(char); return Kuint; - case 'h': *size = sizeof(short); return Kint; - case 'H': *size = sizeof(short); return Kuint; - case 'l': *size = sizeof(long); return Kint; - case 'L': *size = sizeof(long); return Kuint; - case 'j': *size = sizeof(lua_Integer); return Kint; - case 'J': *size = sizeof(lua_Integer); return Kuint; - case 'T': *size = sizeof(size_t); return Kuint; - case 'f': *size = sizeof(float); return Kfloat; - case 'd': *size = sizeof(double); return Kfloat; - case 'n': *size = sizeof(lua_Number); return Kfloat; - case 'i': *size = getnumlimit(h, fmt, sizeof(int)); return Kint; - case 'I': *size = getnumlimit(h, fmt, sizeof(int)); return Kuint; - case 's': *size = getnumlimit(h, fmt, sizeof(size_t)); return Kstring; - case 'c': - *size = getnum(fmt, -1); - if (*size == -1) - luaL_error(h->L, "missing size for format option 'c'"); - return Kchar; - case 'z': return Kzstr; - case 'x': *size = 1; return Kpadding; - case 'X': return Kpaddalign; - case ' ': break; - case '<': h->islittle = 1; break; - case '>': h->islittle = 0; break; - case '=': h->islittle = nativeendian.little; break; - case '!': h->maxalign = getnumlimit(h, fmt, MAXALIGN); break; - default: luaL_error(h->L, "invalid format option '%c'", opt); - } - return Knop; -} - - -/* -** Read, classify, and fill other details about the next option. -** 'psize' is filled with option's size, 'notoalign' with its -** alignment requirements. -** Local variable 'size' gets the size to be aligned. (Kpadal option -** always gets its full alignment, other options are limited by -** the maximum alignment ('maxalign'). Kchar option needs no alignment -** despite its size. -*/ -static KOption getdetails (Header *h, size_t totalsize, - const char **fmt, int *psize, int *ntoalign) { - KOption opt = getoption(h, fmt, psize); - int align = *psize; /* usually, alignment follows size */ - if (opt == Kpaddalign) { /* 'X' gets alignment from following option */ - if (**fmt == '\0' || getoption(h, fmt, &align) == Kchar || align == 0) - luaL_argerror(h->L, 1, "invalid next option for option 'X'"); - } - if (align <= 1 || opt == Kchar) /* need no alignment? */ - *ntoalign = 0; - else { - if (align > h->maxalign) /* enforce maximum alignment */ - align = h->maxalign; - if ((align & (align - 1)) != 0) /* is 'align' not a power of 2? */ - luaL_argerror(h->L, 1, "format asks for alignment not power of 2"); - *ntoalign = (align - (int)(totalsize & (align - 1))) & (align - 1); - } - return opt; -} - - -/* -** Pack integer 'n' with 'size' bytes and 'islittle' endianness. -** The final 'if' handles the case when 'size' is larger than -** the size of a Lua integer, correcting the extra sign-extension -** bytes if necessary (by default they would be zeros). -*/ -static void packint (luaL_Buffer *b, lua_Unsigned n, - int islittle, int size, int neg) { - char *buff = luaL_prepbuffsize(b, size); - int i; - buff[islittle ? 0 : size - 1] = (char)(n & MC); /* first byte */ - for (i = 1; i < size; i++) { - n >>= NB; - buff[islittle ? i : size - 1 - i] = (char)(n & MC); - } - if (neg && size > SZINT) { /* negative number need sign extension? */ - for (i = SZINT; i < size; i++) /* correct extra bytes */ - buff[islittle ? i : size - 1 - i] = (char)MC; - } - luaL_addsize(b, size); /* add result to buffer */ -} - - -/* -** Copy 'size' bytes from 'src' to 'dest', correcting endianness if -** given 'islittle' is different from native endianness. -*/ -static void copywithendian (volatile char *dest, volatile const char *src, - int size, int islittle) { - if (islittle == nativeendian.little) { - while (size-- != 0) - *(dest++) = *(src++); - } - else { - dest += size - 1; - while (size-- != 0) - *(dest--) = *(src++); - } -} - - -static int str_pack (lua_State *L) { - luaL_Buffer b; - Header h; - const char *fmt = luaL_checkstring(L, 1); /* format string */ - int arg = 1; /* current argument to pack */ - size_t totalsize = 0; /* accumulate total size of result */ - initheader(L, &h); - lua_pushnil(L); /* mark to separate arguments from string buffer */ - luaL_buffinit(L, &b); - while (*fmt != '\0') { - int size, ntoalign; - KOption opt = getdetails(&h, totalsize, &fmt, &size, &ntoalign); - totalsize += ntoalign + size; - while (ntoalign-- > 0) - luaL_addchar(&b, LUAL_PACKPADBYTE); /* fill alignment */ - arg++; - switch (opt) { - case Kint: { /* signed integers */ - lua_Integer n = luaL_checkinteger(L, arg); - if (size < SZINT) { /* need overflow check? */ - lua_Integer lim = (lua_Integer)1 << ((size * NB) - 1); - luaL_argcheck(L, -lim <= n && n < lim, arg, "integer overflow"); - } - packint(&b, (lua_Unsigned)n, h.islittle, size, (n < 0)); - break; - } - case Kuint: { /* unsigned integers */ - lua_Integer n = luaL_checkinteger(L, arg); - if (size < SZINT) /* need overflow check? */ - luaL_argcheck(L, (lua_Unsigned)n < ((lua_Unsigned)1 << (size * NB)), - arg, "unsigned overflow"); - packint(&b, (lua_Unsigned)n, h.islittle, size, 0); - break; - } - case Kfloat: { /* floating-point options */ - volatile Ftypes u; - char *buff = luaL_prepbuffsize(&b, size); - lua_Number n = luaL_checknumber(L, arg); /* get argument */ - if (size == sizeof(u.f)) u.f = (float)n; /* copy it into 'u' */ - else if (size == sizeof(u.d)) u.d = (double)n; - else u.n = n; - /* move 'u' to final result, correcting endianness if needed */ - copywithendian(buff, u.buff, size, h.islittle); - luaL_addsize(&b, size); - break; - } - case Kchar: { /* fixed-size string */ - size_t len; - const char *s = luaL_checklstring(L, arg, &len); - luaL_argcheck(L, len <= (size_t)size, arg, - "string longer than given size"); - luaL_addlstring(&b, s, len); /* add string */ - while (len++ < (size_t)size) /* pad extra space */ - luaL_addchar(&b, LUAL_PACKPADBYTE); - break; - } - case Kstring: { /* strings with length count */ - size_t len; - const char *s = luaL_checklstring(L, arg, &len); - luaL_argcheck(L, size >= (int)sizeof(size_t) || - len < ((size_t)1 << (size * NB)), - arg, "string length does not fit in given size"); - packint(&b, (lua_Unsigned)len, h.islittle, size, 0); /* pack length */ - luaL_addlstring(&b, s, len); - totalsize += len; - break; - } - case Kzstr: { /* zero-terminated string */ - size_t len; - const char *s = luaL_checklstring(L, arg, &len); - luaL_argcheck(L, strlen(s) == len, arg, "string contains zeros"); - luaL_addlstring(&b, s, len); - luaL_addchar(&b, '\0'); /* add zero at the end */ - totalsize += len + 1; - break; - } - case Kpadding: luaL_addchar(&b, LUAL_PACKPADBYTE); /* FALLTHROUGH */ - case Kpaddalign: case Knop: - arg--; /* undo increment */ - break; - } - } - luaL_pushresult(&b); - return 1; -} - - -static int str_packsize (lua_State *L) { - Header h; - const char *fmt = luaL_checkstring(L, 1); /* format string */ - size_t totalsize = 0; /* accumulate total size of result */ - initheader(L, &h); - while (*fmt != '\0') { - int size, ntoalign; - KOption opt = getdetails(&h, totalsize, &fmt, &size, &ntoalign); - size += ntoalign; /* total space used by option */ - luaL_argcheck(L, totalsize <= MAXSIZE - size, 1, - "format result too large"); - totalsize += size; - switch (opt) { - case Kstring: /* strings with length count */ - case Kzstr: /* zero-terminated string */ - luaL_argerror(L, 1, "variable-length format"); - /* call never return, but to avoid warnings: *//* FALLTHROUGH */ - default: break; - } - } - lua_pushinteger(L, (lua_Integer)totalsize); - return 1; -} - - -/* -** Unpack an integer with 'size' bytes and 'islittle' endianness. -** If size is smaller than the size of a Lua integer and integer -** is signed, must do sign extension (propagating the sign to the -** higher bits); if size is larger than the size of a Lua integer, -** it must check the unread bytes to see whether they do not cause an -** overflow. -*/ -static lua_Integer unpackint (lua_State *L, const char *str, - int islittle, int size, int issigned) { - lua_Unsigned res = 0; - int i; - int limit = (size <= SZINT) ? size : SZINT; - for (i = limit - 1; i >= 0; i--) { - res <<= NB; - res |= (lua_Unsigned)(unsigned char)str[islittle ? i : size - 1 - i]; - } - if (size < SZINT) { /* real size smaller than lua_Integer? */ - if (issigned) { /* needs sign extension? */ - lua_Unsigned mask = (lua_Unsigned)1 << (size*NB - 1); - res = ((res ^ mask) - mask); /* do sign extension */ - } - } - else if (size > SZINT) { /* must check unread bytes */ - int mask = (!issigned || (lua_Integer)res >= 0) ? 0 : MC; - for (i = limit; i < size; i++) { - if ((unsigned char)str[islittle ? i : size - 1 - i] != mask) - luaL_error(L, "%d-byte integer does not fit into Lua Integer", size); - } - } - return (lua_Integer)res; -} - - -static int str_unpack (lua_State *L) { - Header h; - const char *fmt = luaL_checkstring(L, 1); - size_t ld; - const char *data = luaL_checklstring(L, 2, &ld); - size_t pos = (size_t)posrelat(luaL_optinteger(L, 3, 1), ld) - 1; - int n = 0; /* number of results */ - luaL_argcheck(L, pos <= ld, 3, "initial position out of string"); - initheader(L, &h); - while (*fmt != '\0') { - int size, ntoalign; - KOption opt = getdetails(&h, pos, &fmt, &size, &ntoalign); - if ((size_t)ntoalign + size > ~pos || pos + ntoalign + size > ld) - luaL_argerror(L, 2, "data string too short"); - pos += ntoalign; /* skip alignment */ - /* stack space for item + next position */ - luaL_checkstack(L, 2, "too many results"); - n++; - switch (opt) { - case Kint: - case Kuint: { - lua_Integer res = unpackint(L, data + pos, h.islittle, size, - (opt == Kint)); - lua_pushinteger(L, res); - break; - } - case Kfloat: { - volatile Ftypes u; - lua_Number num; - copywithendian(u.buff, data + pos, size, h.islittle); - if (size == sizeof(u.f)) num = (lua_Number)u.f; - else if (size == sizeof(u.d)) num = (lua_Number)u.d; - else num = u.n; - lua_pushnumber(L, num); - break; - } - case Kchar: { - lua_pushlstring(L, data + pos, size); - break; - } - case Kstring: { - size_t len = (size_t)unpackint(L, data + pos, h.islittle, size, 0); - luaL_argcheck(L, pos + len + size <= ld, 2, "data string too short"); - lua_pushlstring(L, data + pos + size, len); - pos += len; /* skip string */ - break; - } - case Kzstr: { - size_t len = (int)strlen(data + pos); - lua_pushlstring(L, data + pos, len); - pos += len + 1; /* skip string plus final '\0' */ - break; - } - case Kpaddalign: case Kpadding: case Knop: - n--; /* undo increment */ - break; - } - pos += size; - } - lua_pushinteger(L, pos + 1); /* next position */ - return n + 1; -} - -/* }====================================================== */ - - -static const luaL_Reg strlib[] = { - {"byte", str_byte}, - {"char", str_char}, - {"dump", str_dump}, - {"find", str_find}, - {"format", str_format}, - {"gmatch", gmatch}, - {"gsub", str_gsub}, - {"len", str_len}, - {"lower", str_lower}, - {"match", str_match}, - {"rep", str_rep}, - {"reverse", str_reverse}, - {"sub", str_sub}, - {"upper", str_upper}, - {"pack", str_pack}, - {"packsize", str_packsize}, - {"unpack", str_unpack}, - {NULL, NULL} -}; - - -static void createmetatable (lua_State *L) { - lua_createtable(L, 0, 1); /* table to be metatable for strings */ - lua_pushliteral(L, ""); /* dummy string */ - lua_pushvalue(L, -2); /* copy table */ - lua_setmetatable(L, -2); /* set table as metatable for strings */ - lua_pop(L, 1); /* pop dummy string */ - lua_pushvalue(L, -2); /* get string library */ - lua_setfield(L, -2, "__index"); /* metatable.__index = string */ - lua_pop(L, 1); /* pop metatable */ -} - - -/* -** Open string library -*/ -LUAMOD_API int luaopen_string (lua_State *L) { - luaL_newlib(L, strlib); - createmetatable(L); - return 1; -} - |