#define lstrlib_c

#define LUA_LIB

#include "lprefix.h"

#include <ctype.h>

#include <float.h>

#include <limits.h>

#include <locale.h>

#include <math.h>

#include <stddef.h>

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#include "lua.h"

#include "lauxlib.h"

#include "lualib.h"

#if !defined(LUA_MAXCAPTURES)

#define LUA_MAXCAPTURES 32

#define uchar(c) ((unsigned char)(c))

#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;

}

static size_t posrelatI (lua_Integer pos, size_t len) {

if (pos > 0)

return (size_t)pos;

else if (pos == 0)

return 1;

else if (pos < -(lua_Integer)len) /* inverted comparison */

return 1; /* clip to 1 */

else return len + (size_t)pos + 1;

}

static size_t getendpos (lua_State *L, int arg, lua_Integer def,

size_t len) {

lua_Integer pos = luaL_optinteger(L, arg, def);

if (pos > (lua_Integer)len)

return len;

else if (pos >= 0)

return (size_t)pos;

else if (pos < -(lua_Integer)len)

return 0;

else return len + (size_t)pos + 1;

}

static int str_sub (lua_State *L) {

size_t l;

const char *s = luaL_checklstring(L, 1, &l);

size_t start = posrelatI(luaL_checkinteger(L, 2), l);

size_t end = getendpos(L, 3, -1, l);

if (start <= end)

lua_pushlstring(L, s + start - 1, (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 pi = luaL_optinteger(L, 2, 1);

size_t posi = posrelatI(pi, l);

size_t pose = getendpos(L, 3, pi, l);

int n, i;

if (posi > pose) return 0; /* empty interval; return no values */

if (pose - posi >= (size_t)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_Unsigned c = (lua_Unsigned)luaL_checkinteger(L, i);

luaL_argcheck(L, c <= (lua_Unsigned)UCHAR_MAX, i, "value out of range");

p[i - 1] = uchar(c);

}

luaL_pushresultsize(&b, n);

return 1;

}

struct str_Writer {

int init; /* true iff buffer has been initialized */

luaL_Buffer B;

};

static int writer (lua_State *L, const void *b, size_t size, void *ud) {

struct str_Writer *state = (struct str_Writer *)ud;

if (!state->init) {

state->init = 1;

luaL_buffinit(L, &state->B);

}

luaL_addlstring(&state->B, (const char *)b, size);

return 0;

}

static int str_dump (lua_State *L) {

struct str_Writer state;

int strip = lua_toboolean(L, 2);

luaL_checktype(L, 1, LUA_TFUNCTION);

lua_settop(L, 1); /* ensure function is on the top of the stack */

state.init = 0;

if (lua_dump(L, writer, &state, strip) != 0)

return luaL_error(L, "unable to dump given function");

luaL_pushresult(&state.B);

return 1;

}

#if defined(LUA_NOCVTS2N) /* { */

static const luaL_Reg stringmetamethods[] = {

{"__index", NULL}, /* placeholder */

{NULL, NULL}

};

#else /* }{ */

static int tonum (lua_State *L, int arg) {

if (lua_type(L, arg) == LUA_TNUMBER) { /* already a number? */

lua_pushvalue(L, arg);

return 1;

}

else { /* check whether it is a numerical string */

size_t len;

const char *s = lua_tolstring(L, arg, &len);

return (s != NULL && lua_stringtonumber(L, s) == len + 1);

}

}

static void trymt (lua_State *L, const char *mtname) {

lua_settop(L, 2); /* back to the original arguments */

if (lua_type(L, 2) == LUA_TSTRING || !luaL_getmetafield(L, 2, mtname))

luaL_error(L, "attempt to %s a '%s' with a '%s'", mtname + 2,

luaL_typename(L, -2), luaL_typename(L, -1));

lua_insert(L, -3); /* put metamethod before arguments */

lua_call(L, 2, 1); /* call metamethod */

}

static int arith (lua_State *L, int op, const char *mtname) {

if (tonum(L, 1) && tonum(L, 2))

lua_arith(L, op); /* result will be on the top */

else

trymt(L, mtname);

return 1;

}

static int arith_add (lua_State *L) {

return arith(L, LUA_OPADD, "__add");

}

static int arith_sub (lua_State *L) {

return arith(L, LUA_OPSUB, "__sub");

}

static int arith_mul (lua_State *L) {

return arith(L, LUA_OPMUL, "__mul");

}

static int arith_mod (lua_State *L) {

return arith(L, LUA_OPMOD, "__mod");

}

static int arith_pow (lua_State *L) {

return arith(L, LUA_OPPOW, "__pow");

}

static int arith_div (lua_State *L) {

return arith(L, LUA_OPDIV, "__div");

}

static int arith_idiv (lua_State *L) {

return arith(L, LUA_OPIDIV, "__idiv");

}

static int arith_unm (lua_State *L) {

return arith(L, LUA_OPUNM, "__unm");

}

static const luaL_Reg stringmetamethods[] = {

{"__add", arith_add},

{"__sub", arith_sub},

{"__mul", arith_mul},

{"__mod", arith_mod},

{"__pow", arith_pow},

{"__div", arith_div},

{"__idiv", arith_idiv},

{"__unm", arith_unm},

{"__index", NULL}, /* placeholder */

{NULL, NULL}

};

#endif /* } */

#define CAP_UNFINISHED (-1)

#define CAP_POSITION (-2)

typedef struct MatchState {

} MatchState;

static const char *match (MatchState *ms, const char *s, const char *p);

#if !defined(MAXCCALLS)

#define MAXCCALLS 200

#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 size_t get_onecapture (MatchState *ms, int i, const char *s,

const char *e, const char **cap) {

if (i >= ms->level) {

if (i != 0)

luaL_error(ms->L, "invalid capture index %%%d", i + 1);

*cap = s;

return e - s;

}

else {

ptrdiff_t capl = ms->capture[i].len;

*cap = ms->capture[i].init;

if (capl == CAP_UNFINISHED)

luaL_error(ms->L, "unfinished capture");

else if (capl == CAP_POSITION)

lua_pushinteger(ms->L, (ms->capture[i].init - ms->src_init) + 1);

return capl;

}

}

static void push_onecapture (MatchState *ms, int i, const char *s,

const char *e) {

const char *cap;

ptrdiff_t l = get_onecapture(ms, i, s, e, &cap);

if (l != CAP_POSITION)

lua_pushlstring(ms->L, cap, l);

/* else position was already pushed */

}

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 */

}

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);

size_t init = posrelatI(luaL_optinteger(L, 3, 1), ls) - 1;

if (init > ls) { /* start after string's end? */

luaL_pushfail(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, ls - init, 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;

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);

}

luaL_pushfail(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);

}

typedef struct GMatchState {

} 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);

size_t init = posrelatI(luaL_optinteger(L, 3, 1), ls) - 1;

GMatchState *gm;

lua_settop(L, 2); /* keep strings on closure to avoid being collected */

gm = (GMatchState *)lua_newuserdatauv(L, sizeof(GMatchState), 0);

if (init > ls) /* start after string's end? */

init = ls + 1; /* avoid overflows in 's + init' */

prepstate(&gm->ms, L, s, ls, p, lp);

gm->src = s + init; 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;

lua_State *L = ms->L;

const char *news = lua_tolstring(L, 3, &l);

const char *p;

while ((p = (char *)memchr(news, L_ESC, l)) != NULL) {

luaL_addlstring(b, news, p - news);

p++; /* skip ESC */

if (*p == L_ESC) /* '%%' */

luaL_addchar(b, *p);

else if (*p == '0') /* '%0' */

luaL_addlstring(b, s, e - s);

else if (isdigit(uchar(*p))) { /* '%n' */

const char *cap;

ptrdiff_t resl = get_onecapture(ms, *p - '1', s, e, &cap);

if (resl == CAP_POSITION)

luaL_addvalue(b); /* add position to accumulated result */

else

luaL_addlstring(b, cap, resl);

}

else

luaL_error(L, "invalid use of '%c' in replacement string", L_ESC);

l -= p + 1 - news;

news = p + 1;

}

luaL_addlstring(b, news, l);

}

static int 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: { /* call the function */

int n;

lua_pushvalue(L, 3); /* push the function */

n = push_captures(ms, s, e); /* all captures as arguments */

lua_call(L, n, 1); /* call it */

break;

}

case LUA_TTABLE: { /* index the table */

push_onecapture(ms, 0, s, e); /* first capture is the index */

lua_gettable(L, 3);

break;

}

default: { /* LUA_TNUMBER or LUA_TSTRING */

add_s(ms, b, s, e); /* add value to the buffer */

return 1; /* something changed */

}

}

if (!lua_toboolean(L, -1)) { /* nil or false? */

lua_pop(L, 1); /* remove value */

luaL_addlstring(b, s, e - s); /* keep original text */

return 0; /* no changes */

}

else if (!lua_isstring(L, -1))

return luaL_error(L, "invalid replacement value (a %s)",

luaL_typename(L, -1));

else {

luaL_addvalue(b); /* add result to accumulator */

return 1; /* something changed */

}

}

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 */

int changed = 0; /* change flag */

MatchState ms;

luaL_Buffer b;

luaL_argexpected(L, tr == LUA_TNUMBER || tr == LUA_TSTRING ||

tr == LUA_TFUNCTION || tr == LUA_TTABLE, 3,

"string/function/table");

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++;

changed = add_value(&ms, &b, src, e, tr) | changed;

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;

}

if (!changed) /* no changes? */

lua_pushvalue(L, 1); /* return original string */

else { /* something changed */

luaL_addlstring(&b, src, ms.src_end-src);

luaL_pushresult(&b); /* create and return new string */

}

lua_pushinteger(L, n); /* number of substitutions */

return 2;

}

#if !defined(lua_number2strx) /* { */

#define SIZELENMOD (sizeof(LUA_NUMBER_FRMLEN)/sizeof(char))