2020-11-16 14:47:43 +08:00
|
|
|
/*
|
2021-10-08 16:15:33 +08:00
|
|
|
** $Id: lutf8lib.c $
|
2020-11-16 14:47:43 +08:00
|
|
|
** Standard library for UTF-8 manipulation
|
|
|
|
** See Copyright Notice in lua.h
|
|
|
|
*/
|
|
|
|
|
|
|
|
#define lutf8lib_c
|
|
|
|
#define LUA_LIB
|
|
|
|
|
|
|
|
#include "lprefix.h"
|
|
|
|
|
|
|
|
|
|
|
|
#include <assert.h>
|
|
|
|
#include <limits.h>
|
|
|
|
#include <stdlib.h>
|
|
|
|
#include <string.h>
|
|
|
|
|
|
|
|
#include "lua.h"
|
|
|
|
|
|
|
|
#include "lauxlib.h"
|
|
|
|
#include "lualib.h"
|
|
|
|
|
2021-10-08 16:15:33 +08:00
|
|
|
|
|
|
|
#define MAXUNICODE 0x10FFFFu
|
|
|
|
|
|
|
|
#define MAXUTF 0x7FFFFFFFu
|
|
|
|
|
|
|
|
/*
|
|
|
|
** Integer type for decoded UTF-8 values; MAXUTF needs 31 bits.
|
|
|
|
*/
|
|
|
|
#if (UINT_MAX >> 30) >= 1
|
|
|
|
typedef unsigned int utfint;
|
|
|
|
#else
|
|
|
|
typedef unsigned long utfint;
|
|
|
|
#endif
|
|
|
|
|
2020-11-16 14:47:43 +08:00
|
|
|
|
|
|
|
#define iscont(p) ((*(p) & 0xC0) == 0x80)
|
|
|
|
|
|
|
|
|
|
|
|
/* from strlib */
|
|
|
|
/* translate a relative string position: negative means back from end */
|
|
|
|
static lua_Integer u_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;
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
|
|
/*
|
2021-10-08 16:15:33 +08:00
|
|
|
** Decode one UTF-8 sequence, returning NULL if byte sequence is
|
|
|
|
** invalid. The array 'limits' stores the minimum value for each
|
|
|
|
** sequence length, to check for overlong representations. Its first
|
|
|
|
** entry forces an error for non-ascii bytes with no continuation
|
|
|
|
** bytes (count == 0).
|
2020-11-16 14:47:43 +08:00
|
|
|
*/
|
2021-10-08 16:15:33 +08:00
|
|
|
static const char *utf8_decode (const char *s, utfint *val, int strict) {
|
|
|
|
static const utfint limits[] =
|
|
|
|
{~(utfint)0, 0x80, 0x800, 0x10000u, 0x200000u, 0x4000000u};
|
|
|
|
unsigned int c = (unsigned char)s[0];
|
|
|
|
utfint res = 0; /* final result */
|
2020-11-16 14:47:43 +08:00
|
|
|
if (c < 0x80) /* ascii? */
|
|
|
|
res = c;
|
|
|
|
else {
|
|
|
|
int count = 0; /* to count number of continuation bytes */
|
2021-10-08 16:15:33 +08:00
|
|
|
for (; c & 0x40; c <<= 1) { /* while it needs continuation bytes... */
|
|
|
|
unsigned int cc = (unsigned char)s[++count]; /* read next byte */
|
2020-11-16 14:47:43 +08:00
|
|
|
if ((cc & 0xC0) != 0x80) /* not a continuation byte? */
|
|
|
|
return NULL; /* invalid byte sequence */
|
|
|
|
res = (res << 6) | (cc & 0x3F); /* add lower 6 bits from cont. byte */
|
|
|
|
}
|
2021-10-08 16:15:33 +08:00
|
|
|
res |= ((utfint)(c & 0x7F) << (count * 5)); /* add first byte */
|
|
|
|
if (count > 5 || res > MAXUTF || res < limits[count])
|
2020-11-16 14:47:43 +08:00
|
|
|
return NULL; /* invalid byte sequence */
|
|
|
|
s += count; /* skip continuation bytes read */
|
|
|
|
}
|
2021-10-08 16:15:33 +08:00
|
|
|
if (strict) {
|
|
|
|
/* check for invalid code points; too large or surrogates */
|
|
|
|
if (res > MAXUNICODE || (0xD800u <= res && res <= 0xDFFFu))
|
|
|
|
return NULL;
|
|
|
|
}
|
2020-11-16 14:47:43 +08:00
|
|
|
if (val) *val = res;
|
2021-10-08 16:15:33 +08:00
|
|
|
return s + 1; /* +1 to include first byte */
|
2020-11-16 14:47:43 +08:00
|
|
|
}
|
|
|
|
|
|
|
|
|
|
|
|
/*
|
2021-10-08 16:15:33 +08:00
|
|
|
** utf8len(s [, i [, j [, lax]]]) --> number of characters that
|
|
|
|
** start in the range [i,j], or nil + current position if 's' is not
|
|
|
|
** well formed in that interval
|
2020-11-16 14:47:43 +08:00
|
|
|
*/
|
|
|
|
static int utflen (lua_State *L) {
|
2021-10-08 16:15:33 +08:00
|
|
|
lua_Integer n = 0; /* counter for the number of characters */
|
|
|
|
size_t len; /* string length in bytes */
|
2020-11-16 14:47:43 +08:00
|
|
|
const char *s = luaL_checklstring(L, 1, &len);
|
|
|
|
lua_Integer posi = u_posrelat(luaL_optinteger(L, 2, 1), len);
|
|
|
|
lua_Integer posj = u_posrelat(luaL_optinteger(L, 3, -1), len);
|
2021-10-08 16:15:33 +08:00
|
|
|
int lax = lua_toboolean(L, 4);
|
2020-11-16 14:47:43 +08:00
|
|
|
luaL_argcheck(L, 1 <= posi && --posi <= (lua_Integer)len, 2,
|
2021-10-08 16:15:33 +08:00
|
|
|
"initial position out of bounds");
|
2020-11-16 14:47:43 +08:00
|
|
|
luaL_argcheck(L, --posj < (lua_Integer)len, 3,
|
2021-10-08 16:15:33 +08:00
|
|
|
"final position out of bounds");
|
2020-11-16 14:47:43 +08:00
|
|
|
while (posi <= posj) {
|
2021-10-08 16:15:33 +08:00
|
|
|
const char *s1 = utf8_decode(s + posi, NULL, !lax);
|
2020-11-16 14:47:43 +08:00
|
|
|
if (s1 == NULL) { /* conversion error? */
|
2021-10-08 16:15:33 +08:00
|
|
|
luaL_pushfail(L); /* return fail ... */
|
2020-11-16 14:47:43 +08:00
|
|
|
lua_pushinteger(L, posi + 1); /* ... and current position */
|
|
|
|
return 2;
|
|
|
|
}
|
|
|
|
posi = s1 - s;
|
|
|
|
n++;
|
|
|
|
}
|
|
|
|
lua_pushinteger(L, n);
|
|
|
|
return 1;
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
|
|
/*
|
2021-10-08 16:15:33 +08:00
|
|
|
** codepoint(s, [i, [j [, lax]]]) -> returns codepoints for all
|
|
|
|
** characters that start in the range [i,j]
|
2020-11-16 14:47:43 +08:00
|
|
|
*/
|
|
|
|
static int codepoint (lua_State *L) {
|
|
|
|
size_t len;
|
|
|
|
const char *s = luaL_checklstring(L, 1, &len);
|
|
|
|
lua_Integer posi = u_posrelat(luaL_optinteger(L, 2, 1), len);
|
|
|
|
lua_Integer pose = u_posrelat(luaL_optinteger(L, 3, posi), len);
|
2021-10-08 16:15:33 +08:00
|
|
|
int lax = lua_toboolean(L, 4);
|
2020-11-16 14:47:43 +08:00
|
|
|
int n;
|
|
|
|
const char *se;
|
2021-10-08 16:15:33 +08:00
|
|
|
luaL_argcheck(L, posi >= 1, 2, "out of bounds");
|
|
|
|
luaL_argcheck(L, pose <= (lua_Integer)len, 3, "out of bounds");
|
2020-11-16 14:47:43 +08:00
|
|
|
if (posi > pose) return 0; /* empty interval; return no values */
|
|
|
|
if (pose - posi >= INT_MAX) /* (lua_Integer -> int) overflow? */
|
|
|
|
return luaL_error(L, "string slice too long");
|
2021-10-08 16:15:33 +08:00
|
|
|
n = (int)(pose - posi) + 1; /* upper bound for number of returns */
|
2020-11-16 14:47:43 +08:00
|
|
|
luaL_checkstack(L, n, "string slice too long");
|
2021-10-08 16:15:33 +08:00
|
|
|
n = 0; /* count the number of returns */
|
|
|
|
se = s + pose; /* string end */
|
2020-11-16 14:47:43 +08:00
|
|
|
for (s += posi - 1; s < se;) {
|
2021-10-08 16:15:33 +08:00
|
|
|
utfint code;
|
|
|
|
s = utf8_decode(s, &code, !lax);
|
2020-11-16 14:47:43 +08:00
|
|
|
if (s == NULL)
|
|
|
|
return luaL_error(L, "invalid UTF-8 code");
|
|
|
|
lua_pushinteger(L, code);
|
|
|
|
n++;
|
|
|
|
}
|
|
|
|
return n;
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
|
|
static void pushutfchar (lua_State *L, int arg) {
|
2021-10-08 16:15:33 +08:00
|
|
|
lua_Unsigned code = (lua_Unsigned)luaL_checkinteger(L, arg);
|
|
|
|
luaL_argcheck(L, code <= MAXUTF, arg, "value out of range");
|
2020-11-16 14:47:43 +08:00
|
|
|
lua_pushfstring(L, "%U", (long)code);
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
|
|
/*
|
|
|
|
** utfchar(n1, n2, ...) -> char(n1)..char(n2)...
|
|
|
|
*/
|
|
|
|
static int utfchar (lua_State *L) {
|
|
|
|
int n = lua_gettop(L); /* number of arguments */
|
|
|
|
if (n == 1) /* optimize common case of single char */
|
|
|
|
pushutfchar(L, 1);
|
|
|
|
else {
|
|
|
|
int i;
|
|
|
|
luaL_Buffer b;
|
|
|
|
luaL_buffinit(L, &b);
|
|
|
|
for (i = 1; i <= n; i++) {
|
|
|
|
pushutfchar(L, i);
|
|
|
|
luaL_addvalue(&b);
|
|
|
|
}
|
|
|
|
luaL_pushresult(&b);
|
|
|
|
}
|
|
|
|
return 1;
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
|
|
/*
|
|
|
|
** offset(s, n, [i]) -> index where n-th character counting from
|
|
|
|
** position 'i' starts; 0 means character at 'i'.
|
|
|
|
*/
|
|
|
|
static int byteoffset (lua_State *L) {
|
|
|
|
size_t len;
|
|
|
|
const char *s = luaL_checklstring(L, 1, &len);
|
|
|
|
lua_Integer n = luaL_checkinteger(L, 2);
|
|
|
|
lua_Integer posi = (n >= 0) ? 1 : len + 1;
|
|
|
|
posi = u_posrelat(luaL_optinteger(L, 3, posi), len);
|
|
|
|
luaL_argcheck(L, 1 <= posi && --posi <= (lua_Integer)len, 3,
|
2021-10-08 16:15:33 +08:00
|
|
|
"position out of bounds");
|
2020-11-16 14:47:43 +08:00
|
|
|
if (n == 0) {
|
|
|
|
/* find beginning of current byte sequence */
|
|
|
|
while (posi > 0 && iscont(s + posi)) posi--;
|
|
|
|
}
|
|
|
|
else {
|
|
|
|
if (iscont(s + posi))
|
|
|
|
return luaL_error(L, "initial position is a continuation byte");
|
|
|
|
if (n < 0) {
|
|
|
|
while (n < 0 && posi > 0) { /* move back */
|
|
|
|
do { /* find beginning of previous character */
|
|
|
|
posi--;
|
|
|
|
} while (posi > 0 && iscont(s + posi));
|
|
|
|
n++;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
else {
|
|
|
|
n--; /* do not move for 1st character */
|
|
|
|
while (n > 0 && posi < (lua_Integer)len) {
|
|
|
|
do { /* find beginning of next character */
|
|
|
|
posi++;
|
|
|
|
} while (iscont(s + posi)); /* (cannot pass final '\0') */
|
|
|
|
n--;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
}
|
|
|
|
if (n == 0) /* did it find given character? */
|
|
|
|
lua_pushinteger(L, posi + 1);
|
|
|
|
else /* no such character */
|
2021-10-08 16:15:33 +08:00
|
|
|
luaL_pushfail(L);
|
2020-11-16 14:47:43 +08:00
|
|
|
return 1;
|
|
|
|
}
|
|
|
|
|
|
|
|
|
2021-10-08 16:15:33 +08:00
|
|
|
static int iter_aux (lua_State *L, int strict) {
|
2020-11-16 14:47:43 +08:00
|
|
|
size_t len;
|
|
|
|
const char *s = luaL_checklstring(L, 1, &len);
|
|
|
|
lua_Integer n = lua_tointeger(L, 2) - 1;
|
|
|
|
if (n < 0) /* first iteration? */
|
|
|
|
n = 0; /* start from here */
|
|
|
|
else if (n < (lua_Integer)len) {
|
|
|
|
n++; /* skip current byte */
|
|
|
|
while (iscont(s + n)) n++; /* and its continuations */
|
|
|
|
}
|
|
|
|
if (n >= (lua_Integer)len)
|
|
|
|
return 0; /* no more codepoints */
|
|
|
|
else {
|
2021-10-08 16:15:33 +08:00
|
|
|
utfint code;
|
|
|
|
const char *next = utf8_decode(s + n, &code, strict);
|
|
|
|
if (next == NULL)
|
2020-11-16 14:47:43 +08:00
|
|
|
return luaL_error(L, "invalid UTF-8 code");
|
|
|
|
lua_pushinteger(L, n + 1);
|
|
|
|
lua_pushinteger(L, code);
|
|
|
|
return 2;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
|
2021-10-08 16:15:33 +08:00
|
|
|
static int iter_auxstrict (lua_State *L) {
|
|
|
|
return iter_aux(L, 1);
|
|
|
|
}
|
|
|
|
|
|
|
|
static int iter_auxlax (lua_State *L) {
|
|
|
|
return iter_aux(L, 0);
|
|
|
|
}
|
|
|
|
|
|
|
|
|
2020-11-16 14:47:43 +08:00
|
|
|
static int iter_codes (lua_State *L) {
|
2021-10-08 16:15:33 +08:00
|
|
|
int lax = lua_toboolean(L, 2);
|
2020-11-16 14:47:43 +08:00
|
|
|
luaL_checkstring(L, 1);
|
2021-10-08 16:15:33 +08:00
|
|
|
lua_pushcfunction(L, lax ? iter_auxlax : iter_auxstrict);
|
2020-11-16 14:47:43 +08:00
|
|
|
lua_pushvalue(L, 1);
|
|
|
|
lua_pushinteger(L, 0);
|
|
|
|
return 3;
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
|
|
/* pattern to match a single UTF-8 character */
|
2021-10-08 16:15:33 +08:00
|
|
|
#define UTF8PATT "[\0-\x7F\xC2-\xFD][\x80-\xBF]*"
|
2020-11-16 14:47:43 +08:00
|
|
|
|
|
|
|
|
|
|
|
static const luaL_Reg funcs[] = {
|
|
|
|
{"offset", byteoffset},
|
|
|
|
{"codepoint", codepoint},
|
|
|
|
{"char", utfchar},
|
|
|
|
{"len", utflen},
|
|
|
|
{"codes", iter_codes},
|
|
|
|
/* placeholders */
|
|
|
|
{"charpattern", NULL},
|
|
|
|
{NULL, NULL}
|
|
|
|
};
|
|
|
|
|
|
|
|
|
|
|
|
LUAMOD_API int luaopen_utf8 (lua_State *L) {
|
|
|
|
luaL_newlib(L, funcs);
|
|
|
|
lua_pushlstring(L, UTF8PATT, sizeof(UTF8PATT)/sizeof(char) - 1);
|
|
|
|
lua_setfield(L, -2, "charpattern");
|
|
|
|
return 1;
|
|
|
|
}
|
|
|
|
|