1655 lines
46 KiB
C++
1655 lines
46 KiB
C++
|
// This file is part of the Luau programming language and is licensed under MIT License; see LICENSE.txt for details
|
||
|
|
// This code is based on Lua 5.x implementation licensed under MIT License; see lua_LICENSE.txt for details
|
||
|
|
#include "lualib.h"
|
||
|
|
|
||
|
|
#include "lstring.h"
|
||
|
|
|
||
|
|
#include <ctype.h>
|
||
|
|
#include <string.h>
|
||
|
|
#include <stdio.h>
|
||
|
|
|
||
|
|
/* macro to `unsign' a character */
|
||
|
|
#define uchar(c) ((unsigned char)(c))
|
||
|
|
|
||
|
|
static int str_len(lua_State* L)
|
||
|
|
{
|
||
|
|
size_t l;
|
||
|
|
luaL_checklstring(L, 1, &l);
|
||
|
|
lua_pushinteger(L, (int)l);
|
||
|
|
return 1;
|
||
|
|
}
|
||
|
|
|
||
|
|
static int posrelat(int pos, size_t len)
|
||
|
|
{
|
||
|
|
/* relative string position: negative means back from end */
|
||
|
|
if (pos < 0)
|
||
|
|
pos += (int)len + 1;
|
||
|
|
return (pos >= 0) ? pos : 0;
|
||
|
|
}
|
||
|
|
|
||
|
|
static int str_sub(lua_State* L)
|
||
|
|
{
|
||
|
|
size_t l;
|
||
|
|
const char* s = luaL_checklstring(L, 1, &l);
|
||
|
|
int start = posrelat(luaL_checkinteger(L, 2), l);
|
||
|
|
int end = posrelat(luaL_optinteger(L, 3, -1), l);
|
||
|
|
if (start < 1)
|
||
|
|
start = 1;
|
||
|
|
if (end > (int)l)
|
||
|
|
end = (int)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;
|
||
|
|
const char* s = luaL_checklstring(L, 1, &l);
|
||
|
|
luaL_Buffer b;
|
||
|
|
char* ptr = luaL_buffinitsize(L, &b, l);
|
||
|
|
while (l--)
|
||
|
|
*ptr++ = s[l];
|
||
|
|
luaL_pushresultsize(&b, ptr - b.p);
|
||
|
|
return 1;
|
||
|
|
}
|
||
|
|
|
||
|
|
static int str_lower(lua_State* L)
|
||
|
|
{
|
||
|
|
size_t l;
|
||
|
|
const char* s = luaL_checklstring(L, 1, &l);
|
||
|
|
luaL_Buffer b;
|
||
|
|
char* ptr = luaL_buffinitsize(L, &b, l);
|
||
|
|
for (size_t i = 0; i < l; i++)
|
||
|
|
*ptr++ = tolower(uchar(s[i]));
|
||
|
|
luaL_pushresultsize(&b, l);
|
||
|
|
return 1;
|
||
|
|
}
|
||
|
|
|
||
|
|
static int str_upper(lua_State* L)
|
||
|
|
{
|
||
|
|
size_t l;
|
||
|
|
const char* s = luaL_checklstring(L, 1, &l);
|
||
|
|
luaL_Buffer b;
|
||
|
|
char* ptr = luaL_buffinitsize(L, &b, l);
|
||
|
|
for (size_t i = 0; i < l; i++)
|
||
|
|
*ptr++ = toupper(uchar(s[i]));
|
||
|
|
luaL_pushresultsize(&b, l);
|
||
|
|
return 1;
|
||
|
|
}
|
||
|
|
|
||
|
|
static int str_rep(lua_State* L)
|
||
|
|
{
|
||
|
|
size_t l;
|
||
|
|
const char* s = luaL_checklstring(L, 1, &l);
|
||
|
|
int n = luaL_checkinteger(L, 2);
|
||
|
|
|
||
|
|
if (n <= 0)
|
||
|
|
{
|
||
|
|
lua_pushliteral(L, "");
|
||
|
|
return 1;
|
||
|
|
}
|
||
|
|
|
||
|
|
if (l > MAXSSIZE / (size_t)n) // may overflow?
|
||
|
|
luaL_error(L, "resulting string too large");
|
||
|
|
|
||
|
|
luaL_Buffer b;
|
||
|
|
char* ptr = luaL_buffinitsize(L, &b, l * n);
|
||
|
|
|
||
|
|
const char* start = ptr;
|
||
|
|
|
||
|
|
size_t left = l * n;
|
||
|
|
size_t step = l;
|
||
|
|
|
||
|
|
memcpy(ptr, s, l);
|
||
|
|
ptr += l;
|
||
|
|
left -= l;
|
||
|
|
|
||
|
|
// use the increasing 'pattern' inside our target buffer to fill the next part
|
||
|
|
while (step < left)
|
||
|
|
{
|
||
|
|
memcpy(ptr, start, step);
|
||
|
|
ptr += step;
|
||
|
|
left -= step;
|
||
|
|
step <<= 1;
|
||
|
|
}
|
||
|
|
|
||
|
|
// fill tail
|
||
|
|
memcpy(ptr, start, left);
|
||
|
|
ptr += left;
|
||
|
|
|
||
|
|
luaL_pushresultsize(&b, l * n);
|
||
|
|
|
||
|
|
return 1;
|
||
|
|
}
|
||
|
|
|
||
|
|
static int str_byte(lua_State* L)
|
||
|
|
{
|
||
|
|
size_t l;
|
||
|
|
const char* s = luaL_checklstring(L, 1, &l);
|
||
|
|
int posi = posrelat(luaL_optinteger(L, 2, 1), l);
|
||
|
|
int pose = posrelat(luaL_optinteger(L, 3, posi), l);
|
||
|
|
int n, i;
|
||
|
|
if (posi <= 0)
|
||
|
|
posi = 1;
|
||
|
|
if ((size_t)pose > l)
|
||
|
|
pose = (int)l;
|
||
|
|
if (posi > pose)
|
||
|
|
return 0; /* empty interval; return no values */
|
||
|
|
n = (int)(pose - posi + 1);
|
||
|
|
if (posi + n <= pose) /* overflow? */
|
||
|
|
luaL_error(L, "string slice too long");
|
||
|
|
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 */
|
||
|
|
|
||
|
|
luaL_Buffer b;
|
||
|
|
char* ptr = luaL_buffinitsize(L, &b, n);
|
||
|
|
|
||
|
|
for (int i = 1; i <= n; i++)
|
||
|
|
{
|
||
|
|
int c = luaL_checkinteger(L, i);
|
||
|
|
luaL_argcheck(L, uchar(c) == c, i, "invalid value");
|
||
|
|
|
||
|
|
*ptr++ = uchar(c);
|
||
|
|
}
|
||
|
|
luaL_pushresultsize(&b, n);
|
||
|
|
return 1;
|
||
|
|
}
|
||
|
|
|
||
|
|
/*
|
||
|
|
** {======================================================
|
||
|
|
** PATTERN MATCHING
|
||
|
|
** =======================================================
|
||
|
|
*/
|
||
|
|
|
||
|
|
#define CAP_UNFINISHED (-1)
|
||
|
|
#define CAP_POSITION (-2)
|
||
|
|
|
||
|
|
typedef struct MatchState
|
||
|
|
{
|
||
|
|
int matchdepth; /* control for recursive depth (to avoid C stack overflow) */
|
||
|
|
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 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);
|
||
|
|
|
||
|
|
#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)
|
||
|
|
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;
|
||
|
|
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 */
|
||
|
|
/* go through */
|
||
|
|
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");
|
||
|
|
}
|
||
|
|
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, (int)(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 = LUAI_MAXCCALLS;
|
||
|
|
ms->src_init = s;
|
||
|
|
ms->src_end = s + ls;
|
||
|
|
ms->p_end = p + lp;
|
||
|
|
}
|
||
|
|
|
||
|
|
static void reprepstate(MatchState* ms)
|
||
|
|
{
|
||
|
|
ms->level = 0;
|
||
|
|
LUAU_ASSERT(ms->matchdepth == LUAI_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);
|
||
|
|
int init = posrelat(luaL_optinteger(L, 3, 1), ls);
|
||
|
|
if (init < 1)
|
||
|
|
init = 1;
|
||
|
|
else if (init > (int)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 - init + 1, p, lp);
|
||
|
|
if (s2)
|
||
|
|
{
|
||
|
|
lua_pushinteger(L, (int)(s2 - s + 1));
|
||
|
|
lua_pushinteger(L, (int)(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, (int)(s1 - s + 1)); /* start */
|
||
|
|
lua_pushinteger(L, (int)(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);
|
||
|
|
}
|
||
|
|
|
||
|
|
static int gmatch_aux(lua_State* L)
|
||
|
|
{
|
||
|
|
MatchState ms;
|
||
|
|
size_t ls, lp;
|
||
|
|
const char* s = lua_tolstring(L, lua_upvalueindex(1), &ls);
|
||
|
|
const char* p = lua_tolstring(L, lua_upvalueindex(2), &lp);
|
||
|
|
const char* src;
|
||
|
|
prepstate(&ms, L, s, ls, p, lp);
|
||
|
|
for (src = s + (size_t)lua_tointeger(L, lua_upvalueindex(3)); src <= ms.src_end; src++)
|
||
|
|
{
|
||
|
|
const char* e;
|
||
|
|
reprepstate(&ms);
|
||
|
|
if ((e = match(&ms, src, p)) != NULL)
|
||
|
|
{
|
||
|
|
int newstart = (int)(e - s);
|
||
|
|
if (e == src)
|
||
|
|
newstart++; /* empty match? go at least one position */
|
||
|
|
lua_pushinteger(L, newstart);
|
||
|
|
lua_replace(L, lua_upvalueindex(3));
|
||
|
|
return push_captures(&ms, src, e);
|
||
|
|
}
|
||
|
|
}
|
||
|
|
return 0; /* not found */
|
||
|
|
}
|
||
|
|
|
||
|
|
static int gmatch(lua_State* L)
|
||
|
|
{
|
||
|
|
luaL_checkstring(L, 1);
|
||
|
|
luaL_checkstring(L, 2);
|
||
|
|
lua_settop(L, 2);
|
||
|
|
lua_pushinteger(L, 0);
|
||
|
|
lua_pushcclosure(L, gmatch_aux, NULL, 3);
|
||
|
|
return 1;
|
||
|
|
}
|
||
|
|
|
||
|
|
static void add_s(MatchState* ms, luaL_Buffer* b, const char* s, const char* e)
|
||
|
|
{
|
||
|
|
size_t l, i;
|
||
|
|
const char* news = lua_tolstring(ms->L, 3, &l);
|
||
|
|
|
||
|
|
luaL_reservebuffer(b, l, -1);
|
||
|
|
|
||
|
|
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(ms->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_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);
|
||
|
|
const char* p = luaL_checklstring(L, 2, &lp);
|
||
|
|
int tr = lua_type(L, 3);
|
||
|
|
int max_s = luaL_optinteger(L, 4, (int)srcl + 1);
|
||
|
|
int anchor = (*p == '^');
|
||
|
|
int n = 0;
|
||
|
|
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);
|
||
|
|
e = match(&ms, src, p);
|
||
|
|
if (e)
|
||
|
|
{
|
||
|
|
n++;
|
||
|
|
add_value(&ms, &b, src, e, tr);
|
||
|
|
}
|
||
|
|
if (e && e > src) /* non empty match? */
|
||
|
|
src = e; /* skip it */
|
||
|
|
else if (src < ms.src_end)
|
||
|
|
luaL_addchar(&b, *src++);
|
||
|
|
else
|
||
|
|
break;
|
||
|
|
if (anchor)
|
||
|
|
break;
|
||
|
|
}
|
||
|
|
luaL_addlstring(&b, src, ms.src_end - src);
|
||
|
|
luaL_pushresult(&b);
|
||
|
|
lua_pushinteger(L, n); /* number of substitutions */
|
||
|
|
return 2;
|
||
|
|
}
|
||
|
|
|
||
|
|
/* }====================================================== */
|
||
|
|
|
||
|
|
/* valid flags in a format specification */
|
||
|
|
#define FLAGS "-+ #0"
|
||
|
|
/* maximum size of each formatted item (> len(format('%99.99f', -1e308))) */
|
||
|
|
#define MAX_ITEM 512
|
||
|
|
/* maximum size of each format specification (such as '%-099.99d') */
|
||
|
|
#define MAX_FORMAT 32
|
||
|
|
|
||
|
|
static void addquoted(lua_State* L, luaL_Buffer* b, int arg)
|
||
|
|
{
|
||
|
|
size_t l;
|
||
|
|
const char* s = luaL_checklstring(L, arg, &l);
|
||
|
|
|
||
|
|
luaL_reservebuffer(b, l + 2, -1);
|
||
|
|
|
||
|
|
luaL_addchar(b, '"');
|
||
|
|
while (l--)
|
||
|
|
{
|
||
|
|
switch (*s)
|
||
|
|
{
|
||
|
|
case '"':
|
||
|
|
case '\\':
|
||
|
|
case '\n':
|
||
|
|
{
|
||
|
|
luaL_addchar(b, '\\');
|
||
|
|
luaL_addchar(b, *s);
|
||
|
|
break;
|
||
|
|
}
|
||
|
|
case '\r':
|
||
|
|
{
|
||
|
|
luaL_addlstring(b, "\\r", 2);
|
||
|
|
break;
|
||
|
|
}
|
||
|
|
case '\0':
|
||
|
|
{
|
||
|
|
luaL_addlstring(b, "\\000", 4);
|
||
|
|
break;
|
||
|
|
}
|
||
|
|
default:
|
||
|
|
{
|
||
|
|
luaL_addchar(b, *s);
|
||
|
|
break;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
s++;
|
||
|
|
}
|
||
|
|
luaL_addchar(b, '"');
|
||
|
|
}
|
||
|
|
|
||
|
|
static const char* scanformat(lua_State* L, const char* strfrmt, char* form, size_t* size)
|
||
|
|
{
|
||
|
|
const char* p = strfrmt;
|
||
|
|
while (*p != '\0' && strchr(FLAGS, *p) != NULL)
|
||
|
|
p++; /* skip flags */
|
||
|
|
if ((size_t)(p - strfrmt) >= sizeof(FLAGS))
|
||
|
|
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++) = '%';
|
||
|
|
*size = p - strfrmt + 1;
|
||
|
|
strncpy(form, strfrmt, *size);
|
||
|
|
form += *size;
|
||
|
|
*form = '\0';
|
||
|
|
return p;
|
||
|
|
}
|
||
|
|
|
||
|
|
static void addInt64Format(char form[MAX_FORMAT], char formatIndicator, size_t formatItemSize)
|
||
|
|
{
|
||
|
|
LUAU_ASSERT((formatItemSize + 3) <= MAX_FORMAT);
|
||
|
|
LUAU_ASSERT(form[0] == '%');
|
||
|
|
LUAU_ASSERT(form[formatItemSize] != 0);
|
||
|
|
LUAU_ASSERT(form[formatItemSize + 1] == 0);
|
||
|
|
form[formatItemSize + 0] = 'l';
|
||
|
|
form[formatItemSize + 1] = 'l';
|
||
|
|
form[formatItemSize + 2] = formatIndicator;
|
||
|
|
form[formatItemSize + 3] = 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[MAX_ITEM]; /* to store the formatted item */
|
||
|
|
if (++arg > top)
|
||
|
|
luaL_error(L, "missing argument #%d", arg);
|
||
|
|
size_t formatItemSize = 0;
|
||
|
|
strfrmt = scanformat(L, strfrmt, form, &formatItemSize);
|
||
|
|
char formatIndicator = *strfrmt++;
|
||
|
|
switch (formatIndicator)
|
||
|
|
{
|
||
|
|
case 'c':
|
||
|
|
{
|
||
|
|
sprintf(buff, form, (int)luaL_checknumber(L, arg));
|
||
|
|
break;
|
||
|
|
}
|
||
|
|
case 'd':
|
||
|
|
case 'i':
|
||
|
|
{
|
||
|
|
addInt64Format(form, formatIndicator, formatItemSize);
|
||
|
|
sprintf(buff, form, (long long)luaL_checknumber(L, arg));
|
||
|
|
break;
|
||
|
|
}
|
||
|
|
case 'o':
|
||
|
|
case 'u':
|
||
|
|
case 'x':
|
||
|
|
case 'X':
|
||
|
|
{
|
||
|
|
double argValue = luaL_checknumber(L, arg);
|
||
|
|
addInt64Format(form, formatIndicator, formatItemSize);
|
||
|
|
unsigned long long v = (argValue < 0) ? (unsigned long long)(long long)argValue : (unsigned long long)argValue;
|
||
|
|
sprintf(buff, form, v);
|
||
|
|
break;
|
||
|
|
}
|
||
|
|
case 'e':
|
||
|
|
case 'E':
|
||
|
|
case 'f':
|
||
|
|
case 'g':
|
||
|
|
case 'G':
|
||
|
|
{
|
||
|
|
sprintf(buff, form, (double)luaL_checknumber(L, arg));
|
||
|
|
break;
|
||
|
|
}
|
||
|
|
case 'q':
|
||
|
|
{
|
||
|
|
addquoted(L, &b, arg);
|
||
|
|
continue; /* skip the 'addsize' at the end */
|
||
|
|
}
|
||
|
|
case 's':
|
||
|
|
{
|
||
|
|
size_t l;
|
||
|
|
const char* s = luaL_checklstring(L, arg, &l);
|
||
|
|
if (!strchr(form, '.') && l >= 100)
|
||
|
|
{
|
||
|
|
/* no precision and string is too long to be formatted;
|
||
|
|
keep original string */
|
||
|
|
lua_pushvalue(L, arg);
|
||
|
|
luaL_addvalue(&b);
|
||
|
|
continue; /* skip the `addsize' at the end */
|
||
|
|
}
|
||
|
|
else
|
||
|
|
{
|
||
|
|
sprintf(buff, form, s);
|
||
|
|
break;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
default:
|
||
|
|
{ /* also treat cases `pnLlh' */
|
||
|
|
luaL_error(L, "invalid option '%%%c' to 'format'", *(strfrmt - 1));
|
||
|
|
}
|
||
|
|
}
|
||
|
|
luaL_addlstring(&b, buff, strlen(buff));
|
||
|
|
}
|
||
|
|
}
|
||
|
|
luaL_pushresult(&b);
|
||
|
|
return 1;
|
||
|
|
}
|
||
|
|
|
||
|
|
static int str_split(lua_State* L)
|
||
|
|
{
|
||
|
|
size_t haystackLen;
|
||
|
|
const char* haystack = luaL_checklstring(L, 1, &haystackLen);
|
||
|
|
size_t needleLen;
|
||
|
|
const char* needle = luaL_optlstring(L, 2, ",", &needleLen);
|
||
|
|
|
||
|
|
const char* begin = haystack;
|
||
|
|
const char* end = haystack + haystackLen;
|
||
|
|
const char* spanStart = begin;
|
||
|
|
int numMatches = 0;
|
||
|
|
|
||
|
|
lua_createtable(L, 0, 0);
|
||
|
|
|
||
|
|
if (needleLen == 0)
|
||
|
|
begin++;
|
||
|
|
|
||
|
|
// Don't iterate the last needleLen - 1 bytes of the string - they are
|
||
|
|
// impossible to be splits and would let us memcmp past the end of the
|
||
|
|
// buffer.
|
||
|
|
for (const char* iter = begin; iter <= end - needleLen; iter++)
|
||
|
|
{
|
||
|
|
// Use of memcmp here instead of strncmp is so that we allow embedded
|
||
|
|
// nulls to be used in either of the haystack or the needle strings.
|
||
|
|
// Most Lua string APIs allow embedded nulls, and this should be no
|
||
|
|
// exception.
|
||
|
|
if (memcmp(iter, needle, needleLen) == 0)
|
||
|
|
{
|
||
|
|
lua_pushinteger(L, ++numMatches);
|
||
|
|
lua_pushlstring(L, spanStart, iter - spanStart);
|
||
|
|
lua_settable(L, -3);
|
||
|
|
|
||
|
|
spanStart = iter + needleLen;
|
||
|
|
if (needleLen > 0)
|
||
|
|
iter += needleLen - 1;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
if (needleLen > 0)
|
||
|
|
{
|
||
|
|
lua_pushinteger(L, ++numMatches);
|
||
|
|
lua_pushlstring(L, spanStart, end - spanStart);
|
||
|
|
lua_settable(L, -3);
|
||
|
|
}
|
||
|
|
|
||
|
|
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)
|
||
|
|
|
||
|
|
/* internal size of integers used for pack/unpack */
|
||
|
|
#define SZINT (int)sizeof(long long)
|
||
|
|
|
||
|
|
/* dummy union to get native endianness */
|
||
|
|
static const union
|
||
|
|
{
|
||
|
|
int dummy;
|
||
|
|
char little; /* true iff machine is little endian */
|
||
|
|
} nativeendian = {1};
|
||
|
|
|
||
|
|
/* assume we need to align for double & pointers */
|
||
|
|
#define MAXALIGN 8
|
||
|
|
|
||
|
|
/*
|
||
|
|
** Union for serializing floats
|
||
|
|
*/
|
||
|
|
typedef union Ftypes
|
||
|
|
{
|
||
|
|
float f;
|
||
|
|
double d;
|
||
|
|
double n;
|
||
|
|
char buff[5 * sizeof(double)]; /* 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(Header* h, 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_MAX - 9) / 10);
|
||
|
|
if (a > MAXSSIZE || digit(**fmt))
|
||
|
|
luaL_error(h->L, "size specifier is too large");
|
||
|
|
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(h, 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 = 1;
|
||
|
|
return Kint;
|
||
|
|
case 'B':
|
||
|
|
*size = 1;
|
||
|
|
return Kuint;
|
||
|
|
case 'h':
|
||
|
|
*size = 2;
|
||
|
|
return Kint;
|
||
|
|
case 'H':
|
||
|
|
*size = 2;
|
||
|
|
return Kuint;
|
||
|
|
case 'l':
|
||
|
|
*size = 8;
|
||
|
|
return Kint;
|
||
|
|
case 'L':
|
||
|
|
*size = 8;
|
||
|
|
return Kuint;
|
||
|
|
case 'j':
|
||
|
|
*size = 4;
|
||
|
|
return Kint;
|
||
|
|
case 'J':
|
||
|
|
*size = 4;
|
||
|
|
return Kuint;
|
||
|
|
case 'T':
|
||
|
|
*size = 4;
|
||
|
|
return Kuint;
|
||
|
|
case 'f':
|
||
|
|
*size = 4;
|
||
|
|
return Kfloat;
|
||
|
|
case 'd':
|
||
|
|
*size = 8;
|
||
|
|
return Kfloat;
|
||
|
|
case 'n':
|
||
|
|
*size = 8;
|
||
|
|
return Kfloat;
|
||
|
|
case 'i':
|
||
|
|
*size = getnumlimit(h, fmt, 4);
|
||
|
|
return Kint;
|
||
|
|
case 'I':
|
||
|
|
*size = getnumlimit(h, fmt, 4);
|
||
|
|
return Kuint;
|
||
|
|
case 's':
|
||
|
|
*size = getnumlimit(h, fmt, 4);
|
||
|
|
return Kstring;
|
||
|
|
case 'c':
|
||
|
|
*size = getnum(h, 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, unsigned long long n, int islittle, int size, int neg)
|
||
|
|
{
|
||
|
|
LUAU_ASSERT(size <= MAXINTSIZE);
|
||
|
|
char buff[MAXINTSIZE];
|
||
|
|
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_addlstring(b, buff, 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 */
|
||
|
|
long long n = (long long)luaL_checknumber(L, arg);
|
||
|
|
if (size < SZINT)
|
||
|
|
{ /* need overflow check? */
|
||
|
|
long long lim = (long long)1 << ((size * NB) - 1);
|
||
|
|
luaL_argcheck(L, -lim <= n && n < lim, arg, "integer overflow");
|
||
|
|
}
|
||
|
|
packint(&b, n, h.islittle, size, (n < 0));
|
||
|
|
break;
|
||
|
|
}
|
||
|
|
case Kuint:
|
||
|
|
{ /* unsigned integers */
|
||
|
|
long long n = (long long)luaL_checknumber(L, arg);
|
||
|
|
if (size < SZINT) /* need overflow check? */
|
||
|
|
luaL_argcheck(L, (unsigned long long)n < ((unsigned long long)1 << (size * NB)), arg, "unsigned overflow");
|
||
|
|
packint(&b, (unsigned long long)n, h.islittle, size, 0);
|
||
|
|
break;
|
||
|
|
}
|
||
|
|
case Kfloat:
|
||
|
|
{ /* floating-point options */
|
||
|
|
volatile Ftypes u;
|
||
|
|
char buff[MAXINTSIZE];
|
||
|
|
double 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_addlstring(&b, buff, 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, 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 */
|
||
|
|
int totalsize = 0; /* accumulate total size of result */
|
||
|
|
initheader(L, &h);
|
||
|
|
while (*fmt != '\0')
|
||
|
|
{
|
||
|
|
int size, ntoalign;
|
||
|
|
KOption opt = getdetails(&h, totalsize, &fmt, &size, &ntoalign);
|
||
|
|
luaL_argcheck(L, opt != Kstring && opt != Kzstr, 1, "variable-length format");
|
||
|
|
size += ntoalign; /* total space used by option */
|
||
|
|
luaL_argcheck(L, totalsize <= MAXSSIZE - size, 1, "format result too large");
|
||
|
|
totalsize += size;
|
||
|
|
}
|
||
|
|
lua_pushinteger(L, 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 long long unpackint(lua_State* L, const char* str, int islittle, int size, int issigned)
|
||
|
|
{
|
||
|
|
unsigned long long res = 0;
|
||
|
|
int i;
|
||
|
|
int limit = (size <= SZINT) ? size : SZINT;
|
||
|
|
for (i = limit - 1; i >= 0; i--)
|
||
|
|
{
|
||
|
|
res <<= NB;
|
||
|
|
res |= (unsigned char)str[islittle ? i : size - 1 - i];
|
||
|
|
}
|
||
|
|
if (size < SZINT)
|
||
|
|
{ /* real size smaller than int? */
|
||
|
|
if (issigned)
|
||
|
|
{ /* needs sign extension? */
|
||
|
|
unsigned long long mask = (unsigned long long)1 << (size * NB - 1);
|
||
|
|
res = ((res ^ mask) - mask); /* do sign extension */
|
||
|
|
}
|
||
|
|
}
|
||
|
|
else if (size > SZINT)
|
||
|
|
{ /* must check unread bytes */
|
||
|
|
int mask = (!issigned || (long long)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 (long long)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);
|
||
|
|
int pos = posrelat(luaL_optinteger(L, 3, 1), ld) - 1;
|
||
|
|
if (pos < 0)
|
||
|
|
pos = 0;
|
||
|
|
int n = 0; /* number of results */
|
||
|
|
luaL_argcheck(L, size_t(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);
|
||
|
|
luaL_argcheck(L, (size_t)ntoalign + size <= ld - pos, 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:
|
||
|
|
{
|
||
|
|
long long res = unpackint(L, data + pos, h.islittle, size, true);
|
||
|
|
lua_pushnumber(L, (double)res);
|
||
|
|
break;
|
||
|
|
}
|
||
|
|
case Kuint:
|
||
|
|
{
|
||
|
|
unsigned long long res = unpackint(L, data + pos, h.islittle, size, false);
|
||
|
|
lua_pushnumber(L, (double)res);
|
||
|
|
break;
|
||
|
|
}
|
||
|
|
case Kfloat:
|
||
|
|
{
|
||
|
|
volatile Ftypes u;
|
||
|
|
double num;
|
||
|
|
copywithendian(u.buff, data + pos, size, h.islittle);
|
||
|
|
if (size == sizeof(u.f))
|
||
|
|
num = (double)u.f;
|
||
|
|
else if (size == sizeof(u.d))
|
||
|
|
num = (double)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, len <= ld - pos - size, 2, "data string too short");
|
||
|
|
lua_pushlstring(L, data + pos + size, len);
|
||
|
|
pos += (int)len; /* skip string */
|
||
|
|
break;
|
||
|
|
}
|
||
|
|
case Kzstr:
|
||
|
|
{
|
||
|
|
size_t len = strlen(data + pos);
|
||
|
|
luaL_argcheck(L, pos + len < ld, 2, "unfinished string for format 'z'");
|
||
|
|
lua_pushlstring(L, data + pos, len);
|
||
|
|
pos += (int)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},
|
||
|
|
{"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},
|
||
|
|
{"split", str_split},
|
||
|
|
{"pack", str_pack},
|
||
|
|
{"packsize", str_packsize},
|
||
|
|
{"unpack", str_unpack},
|
||
|
|
{NULL, NULL},
|
||
|
|
};
|
||
|
|
|
||
|
|
static void createmetatable(lua_State* L)
|
||
|
|
{
|
||
|
|
lua_createtable(L, 0, 1); /* create metatable for strings */
|
||
|
|
lua_pushliteral(L, ""); /* dummy string */
|
||
|
|
lua_pushvalue(L, -2);
|
||
|
|
lua_setmetatable(L, -2); /* set string metatable */
|
||
|
|
lua_pop(L, 1); /* pop dummy string */
|
||
|
|
lua_pushvalue(L, -2); /* string library... */
|
||
|
|
lua_setfield(L, -2, "__index"); /* ...is the __index metamethod */
|
||
|
|
lua_pop(L, 1); /* pop metatable */
|
||
|
|
}
|
||
|
|
|
||
|
|
/*
|
||
|
|
** Open string library
|
||
|
|
*/
|
||
|
|
int luaopen_string(lua_State* L)
|
||
|
|
{
|
||
|
|
luaL_register(L, LUA_STRLIBNAME, strlib);
|
||
|
|
createmetatable(L);
|
||
|
|
|
||
|
|
return 1;
|
||
|
|
}
|