diff options
Diffstat (limited to '3rdparty/lua/src/lstrlib.c')
-rw-r--r-- | 3rdparty/lua/src/lstrlib.c | 1584 |
1 files changed, 1584 insertions, 0 deletions
diff --git a/3rdparty/lua/src/lstrlib.c b/3rdparty/lua/src/lstrlib.c new file mode 100644 index 0000000..c7aa755 --- /dev/null +++ b/3rdparty/lua/src/lstrlib.c @@ -0,0 +1,1584 @@ +/* +** $Id: lstrlib.c,v 1.254 2016/12/22 13:08:50 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 'inf' or 'NaN', format it like '%g' */ + if (x != x || x == (lua_Number)HUGE_VAL || x == -(lua_Number)HUGE_VAL) + return l_sprintf(buff, sz, LUA_NUMBER_FMT, (LUAI_UACNUMBER)x); + else if (x == 0) { /* can be -0... */ + /* create "0" or "-0" followed by exponent */ + return l_sprintf(buff, sz, LUA_NUMBER_FMT "x0p+0", (LUAI_UACNUMBER)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 = (char *)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, (LUAI_UACINT)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, (LUAI_UACINT)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': { + lua_Number n = luaL_checknumber(L, arg); + addlenmod(form, LUA_NUMBER_FRMLEN); + nb = l_sprintf(buff, MAX_ITEM, form, (LUAI_UACNUMBER)n); + 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; +} + |