lite-xl/src/api/utf8.c

1306 lines
38 KiB
C

/*
* Integration of https://github.com/starwing/luautf8
*
* Copyright (c) 2018 Xavier Wang
*
* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#include <lua.h>
#include <lauxlib.h>
#include <lualib.h>
#include <assert.h>
#include <string.h>
#include "../unidata.h"
/* UTF-8 string operations */
#define UTF8_BUFFSZ 8
#define UTF8_MAX 0x7FFFFFFFu
#define UTF8_MAXCP 0x10FFFFu
#define iscont(p) ((*(p) & 0xC0) == 0x80)
#define CAST(tp,expr) ((tp)(expr))
#ifndef LUA_QL
# define LUA_QL(x) "'" x "'"
#endif
static int utf8_invalid (utfint ch)
{ return (ch > UTF8_MAXCP || (0xD800u <= ch && ch <= 0xDFFFu)); }
static size_t utf8_encode (char *buff, utfint x) {
int n = 1; /* number of bytes put in buffer (backwards) */
lua_assert(x <= UTF8_MAX);
if (x < 0x80) /* ascii? */
buff[UTF8_BUFFSZ - 1] = x & 0x7F;
else { /* need continuation bytes */
utfint mfb = 0x3f; /* maximum that fits in first byte */
do { /* add continuation bytes */
buff[UTF8_BUFFSZ - (n++)] = 0x80 | (x & 0x3f);
x >>= 6; /* remove added bits */
mfb >>= 1; /* now there is one less bit available in first byte */
} while (x > mfb); /* still needs continuation byte? */
buff[UTF8_BUFFSZ - n] = ((~mfb << 1) | x) & 0xFF; /* add first byte */
}
return n;
}
static const char *utf8_decode (const char *s, utfint *val, int strict) {
static const utfint limits[] =
{~0u, 0x80u, 0x800u, 0x10000u, 0x200000u, 0x4000000u};
unsigned int c = (unsigned char)s[0];
utfint res = 0; /* final result */
if (c < 0x80) /* ascii? */
res = c;
else {
int count = 0; /* to count number of continuation bytes */
for (; c & 0x40; c <<= 1) { /* while it needs continuation bytes... */
unsigned int cc = (unsigned char)s[++count]; /* read next byte */
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 */
}
res |= ((utfint)(c & 0x7F) << (count * 5)); /* add first byte */
if (count > 5 || res > UTF8_MAX || res < limits[count])
return NULL; /* invalid byte sequence */
s += count; /* skip continuation bytes read */
}
if (strict) {
/* check for invalid code points; too large or surrogates */
if (res > UTF8_MAXCP || (0xD800u <= res && res <= 0xDFFFu))
return NULL;
}
if (val) *val = res;
return s + 1; /* +1 to include first byte */
}
static const char *utf8_prev (const char *s, const char *e) {
while (s < e && iscont(e - 1)) --e;
return s < e ? e - 1 : s;
}
static const char *utf8_next (const char *s, const char *e) {
while (s < e && iscont(s + 1)) ++s;
return s < e ? s + 1 : e;
}
static size_t utf8_length (const char *s, const char *e) {
size_t i;
for (i = 0; s < e; ++i)
s = utf8_next(s, e);
return i;
}
static const char *utf8_offset (const char *s, const char *e, lua_Integer offset, lua_Integer idx) {
const char *p = s + offset - 1;
if (idx >= 0) {
while (p < e && idx > 0)
p = utf8_next(p, e), --idx;
return idx == 0 ? p : NULL;
} else {
while (s < p && idx < 0)
p = utf8_prev(s, p), ++idx;
return idx == 0 ? p : NULL;
}
}
static const char *utf8_relat (const char *s, const char *e, int idx) {
return idx >= 0 ?
utf8_offset(s, e, 1, idx - 1) :
utf8_offset(s, e, e-s+1, idx);
}
static int utf8_range(const char *s, const char *e, lua_Integer *i, lua_Integer *j) {
const char *ps = utf8_relat(s, e, CAST(int, *i));
const char *pe = utf8_relat(s, e, CAST(int, *j));
*i = (ps ? ps : (*i > 0 ? e : s)) - s;
*j = (pe ? utf8_next(pe, e) : (*j > 0 ? e : s)) - s;
return *i < *j;
}
/* Unicode character categories */
#define table_size(t) (sizeof(t)/sizeof((t)[0]))
#define utf8_categories(X) \
X('a', alpha) \
X('c', cntrl) \
X('d', digit) \
X('l', lower) \
X('p', punct) \
X('s', space) \
X('t', compose) \
X('u', upper) \
X('x', xdigit)
#define utf8_converters(X) \
X(lower) \
X(upper) \
X(title) \
X(fold)
static int find_in_range (range_table *t, size_t size, utfint ch) {
size_t begin, end;
begin = 0;
end = size;
while (begin < end) {
size_t mid = (begin + end) / 2;
if (t[mid].last < ch)
begin = mid + 1;
else if (t[mid].first > ch)
end = mid;
else
return (ch - t[mid].first) % t[mid].step == 0;
}
return 0;
}
static int convert_char (conv_table *t, size_t size, utfint ch) {
size_t begin, end;
begin = 0;
end = size;
while (begin < end) {
size_t mid = (begin + end) / 2;
if (t[mid].last < ch)
begin = mid + 1;
else if (t[mid].first > ch)
end = mid;
else if ((ch - t[mid].first) % t[mid].step == 0)
return ch + t[mid].offset;
else
return ch;
}
return ch;
}
#define define_category(cls, name) static int utf8_is##name (utfint ch)\
{ return find_in_range(name##_table, table_size(name##_table), ch); }
#define define_converter(name) static utfint utf8_to##name (utfint ch) \
{ return convert_char(to##name##_table, table_size(to##name##_table), ch); }
utf8_categories(define_category)
utf8_converters(define_converter)
#undef define_category
#undef define_converter
static int utf8_isgraph (utfint ch) {
if (find_in_range(space_table, table_size(space_table), ch))
return 0;
if (find_in_range(graph_table, table_size(graph_table), ch))
return 1;
if (find_in_range(compose_table, table_size(compose_table), ch))
return 1;
return 0;
}
static int utf8_isalnum (utfint ch) {
if (find_in_range(alpha_table, table_size(alpha_table), ch))
return 1;
if (find_in_range(alnum_extend_table, table_size(alnum_extend_table), ch))
return 1;
return 0;
}
static int utf8_width (utfint ch, int ambi_is_single) {
if (find_in_range(doublewidth_table, table_size(doublewidth_table), ch))
return 2;
if (find_in_range(ambiwidth_table, table_size(ambiwidth_table), ch))
return ambi_is_single ? 1 : 2;
if (find_in_range(compose_table, table_size(compose_table), ch))
return 0;
if (find_in_range(unprintable_table, table_size(unprintable_table), ch))
return 0;
return 1;
}
/* string module compatible interface */
static int typeerror (lua_State *L, int idx, const char *tname)
{ return luaL_error(L, "%s expected, got %s", tname, luaL_typename(L, idx)); }
static const char *check_utf8 (lua_State *L, int idx, const char **end) {
size_t len;
const char *s = luaL_checklstring(L, idx, &len);
if (end) *end = s+len;
return s;
}
static const char *to_utf8 (lua_State *L, int idx, const char **end) {
size_t len;
const char *s = lua_tolstring(L, idx, &len);
if (end) *end = s+len;
return s;
}
static const char *utf8_safe_decode (lua_State *L, const char *p, utfint *pval) {
p = utf8_decode(p, pval, 0);
if (p == NULL) luaL_error(L, "invalid UTF-8 code");
return p;
}
static void add_utf8char (luaL_Buffer *b, utfint ch) {
char buff[UTF8_BUFFSZ];
size_t n = utf8_encode(buff, ch);
luaL_addlstring(b, buff+UTF8_BUFFSZ-n, n);
}
static lua_Integer byte_relat (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 Lutf8_len (lua_State *L) {
size_t len, n;
const char *s = luaL_checklstring(L, 1, &len), *p, *e;
lua_Integer posi = byte_relat(luaL_optinteger(L, 2, 1), len);
lua_Integer pose = byte_relat(luaL_optinteger(L, 3, -1), len);
int lax = lua_toboolean(L, 4);
luaL_argcheck(L, 1 <= posi && --posi <= (lua_Integer)len, 2,
"initial position out of string");
luaL_argcheck(L, --pose < (lua_Integer)len, 3,
"final position out of string");
for (n = 0, p=s+posi, e=s+pose+1; p < e; ++n) {
if (lax)
p = utf8_next(p, e);
else {
utfint ch;
const char *np = utf8_decode(p, &ch, !lax);
if (np == NULL || utf8_invalid(ch)) {
lua_pushnil(L);
lua_pushinteger(L, p - s + 1);
return 2;
}
p = np;
}
}
lua_pushinteger(L, n);
return 1;
}
static int Lutf8_sub (lua_State *L) {
const char *e, *s = check_utf8(L, 1, &e);
lua_Integer posi = luaL_checkinteger(L, 2);
lua_Integer pose = luaL_optinteger(L, 3, -1);
if (utf8_range(s, e, &posi, &pose))
lua_pushlstring(L, s+posi, pose-posi);
else
lua_pushliteral(L, "");
return 1;
}
static int Lutf8_reverse (lua_State *L) {
luaL_Buffer b;
const char *prev, *pprev, *ends, *e, *s = check_utf8(L, 1, &e);
(void) ends;
int lax = lua_toboolean(L, 2);
luaL_buffinit(L, &b);
if (lax) {
for (prev = e; s < prev; e = prev) {
prev = utf8_prev(s, prev);
luaL_addlstring(&b, prev, e-prev);
}
} else {
for (prev = e; s < prev; prev = pprev) {
utfint code = 0;
ends = utf8_safe_decode(L, pprev = utf8_prev(s, prev), &code);
assert(ends == prev);
if (utf8_invalid(code))
return luaL_error(L, "invalid UTF-8 code");
if (!utf8_iscompose(code)) {
luaL_addlstring(&b, pprev, e-pprev);
e = pprev;
}
}
}
luaL_pushresult(&b);
return 1;
}
static int Lutf8_byte (lua_State *L) {
size_t n = 0;
const char *e, *s = check_utf8(L, 1, &e);
lua_Integer posi = luaL_optinteger(L, 2, 1);
lua_Integer pose = luaL_optinteger(L, 3, posi);
if (utf8_range(s, e, &posi, &pose)) {
for (e = s + pose, s = s + posi; s < e; ++n) {
utfint ch = 0;
s = utf8_safe_decode(L, s, &ch);
lua_pushinteger(L, ch);
}
}
return CAST(int, n);
}
static int Lutf8_codepoint (lua_State *L) {
const char *e, *s = check_utf8(L, 1, &e);
size_t len = e-s;
lua_Integer posi = byte_relat(luaL_optinteger(L, 2, 1), len);
lua_Integer pose = byte_relat(luaL_optinteger(L, 3, posi), len);
int lax = lua_toboolean(L, 4);
int n;
const char *se;
luaL_argcheck(L, posi >= 1, 2, "out of range");
luaL_argcheck(L, pose <= (lua_Integer)len, 3, "out of range");
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");
n = (int)(pose - posi + 1);
luaL_checkstack(L, n, "string slice too long");
n = 0; /* count the number of returns */
se = s + pose; /* string end */
for (n = 0, s += posi - 1; s < se;) {
utfint code = 0;
s = utf8_safe_decode(L, s, &code);
if (!lax && utf8_invalid(code))
return luaL_error(L, "invalid UTF-8 code");
lua_pushinteger(L, code);
n++;
}
return n;
}
static int Lutf8_char (lua_State *L) {
int i, n = lua_gettop(L); /* number of arguments */
luaL_Buffer b;
luaL_buffinit(L, &b);
for (i = 1; i <= n; ++i) {
lua_Integer code = luaL_checkinteger(L, i);
luaL_argcheck(L, code <= UTF8_MAXCP, i, "value out of range");
add_utf8char(&b, CAST(utfint, code));
}
luaL_pushresult(&b);
return 1;
}
#define bind_converter(name) \
static int Lutf8_##name (lua_State *L) { \
int t = lua_type(L, 1); \
if (t == LUA_TNUMBER) \
lua_pushinteger(L, utf8_to##name(CAST(utfint, lua_tointeger(L, 1)))); \
else if (t == LUA_TSTRING) { \
luaL_Buffer b; \
const char *e, *s = to_utf8(L, 1, &e); \
luaL_buffinit(L, &b); \
while (s < e) { \
utfint ch = 0; \
s = utf8_safe_decode(L, s, &ch); \
add_utf8char(&b, utf8_to##name(ch)); \
} \
luaL_pushresult(&b); \
} \
else return typeerror(L, 1, "number/string"); \
return 1; \
}
utf8_converters(bind_converter)
#undef bind_converter
/* unicode extra interface */
static const char *parse_escape (lua_State *L, const char *s, const char *e, int hex, utfint *pch) {
utfint code = 0;
int in_bracket = 0;
if (*s == '{') ++s, in_bracket = 1;
for (; s < e; ++s) {
utfint ch = (unsigned char)*s;
if (ch >= '0' && ch <= '9') ch = ch - '0';
else if (hex && ch >= 'A' && ch <= 'F') ch = 10 + (ch - 'A');
else if (hex && ch >= 'a' && ch <= 'f') ch = 10 + (ch - 'a');
else if (!in_bracket) break;
else if (ch == '}') { ++s; break; }
else luaL_error(L, "invalid escape '%c'", ch);
code *= hex ? 16 : 10;
code += ch;
}
*pch = code;
return s;
}
static int Lutf8_escape (lua_State *L) {
const char *e, *s = check_utf8(L, 1, &e);
luaL_Buffer b;
luaL_buffinit(L, &b);
while (s < e) {
utfint ch = 0;
s = utf8_safe_decode(L, s, &ch);
if (ch == '%') {
int hex = 0;
switch (*s) {
case '0': case '1': case '2': case '3':
case '4': case '5': case '6': case '7':
case '8': case '9': case '{':
break;
case 'x': case 'X': hex = 1; /* fall through */
case 'u': case 'U': if (s+1 < e) { ++s; break; }
/* fall through */
default:
s = utf8_safe_decode(L, s, &ch);
goto next;
}
s = parse_escape(L, s, e, hex, &ch);
}
next:
add_utf8char(&b, ch);
}
luaL_pushresult(&b);
return 1;
}
static int Lutf8_insert (lua_State *L) {
const char *e, *s = check_utf8(L, 1, &e);
size_t sublen;
const char *subs;
luaL_Buffer b;
int nargs = 2;
const char *first = e;
if (lua_type(L, 2) == LUA_TNUMBER) {
int idx = (int)lua_tointeger(L, 2);
if (idx != 0) first = utf8_relat(s, e, idx);
luaL_argcheck(L, first, 2, "invalid index");
++nargs;
}
subs = luaL_checklstring(L, nargs, &sublen);
luaL_buffinit(L, &b);
luaL_addlstring(&b, s, first-s);
luaL_addlstring(&b, subs, sublen);
luaL_addlstring(&b, first, e-first);
luaL_pushresult(&b);
return 1;
}
static int Lutf8_remove (lua_State *L) {
const char *e, *s = check_utf8(L, 1, &e);
lua_Integer posi = luaL_optinteger(L, 2, -1);
lua_Integer pose = luaL_optinteger(L, 3, -1);
if (!utf8_range(s, e, &posi, &pose))
lua_settop(L, 1);
else {
luaL_Buffer b;
luaL_buffinit(L, &b);
luaL_addlstring(&b, s, posi);
luaL_addlstring(&b, s+pose, e-s-pose);
luaL_pushresult(&b);
}
return 1;
}
static int push_offset (lua_State *L, const char *s, const char *e, lua_Integer offset, lua_Integer idx) {
utfint ch = 0;
const char *p;
if (idx != 0)
p = utf8_offset(s, e, offset, idx);
else if (p = s+offset-1, iscont(p))
p = utf8_prev(s, p);
if (p == NULL || p == e) return 0;
utf8_decode(p, &ch, 0);
lua_pushinteger(L, p-s+1);
lua_pushinteger(L, ch);
return 2;
}
static int Lutf8_charpos (lua_State *L) {
const char *e, *s = check_utf8(L, 1, &e);
lua_Integer offset = 1;
if (lua_isnoneornil(L, 3)) {
lua_Integer idx = luaL_optinteger(L, 2, 0);
if (idx > 0) --idx;
else if (idx < 0) offset = e-s+1;
return push_offset(L, s, e, offset, idx);
}
offset = byte_relat(luaL_optinteger(L, 2, 1), e-s);
if (offset < 1) offset = 1;
return push_offset(L, s, e, offset, luaL_checkinteger(L, 3));
}
static int Lutf8_offset (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 = byte_relat(luaL_optinteger(L, 3, posi), len);
luaL_argcheck(L, 1 <= posi && --posi <= (lua_Integer)len, 3,
"position out of range");
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 */
lua_pushnil(L);
return 1;
}
static int Lutf8_next (lua_State *L) {
const char *e, *s = check_utf8(L, 1, &e);
lua_Integer offset = byte_relat(luaL_optinteger(L, 2, 1), e-s);
lua_Integer idx = luaL_optinteger(L, 3, !lua_isnoneornil(L, 2));
return push_offset(L, s, e, offset, idx);
}
static int iter_aux (lua_State *L, int strict) {
const char *e, *s = check_utf8(L, 1, &e);
int n = CAST(int, lua_tointeger(L, 2));
const char *p = n <= 0 ? s : utf8_next(s+n-1, e);
if (p < e) {
utfint code = 0;
utf8_safe_decode(L, p, &code);
if (strict && utf8_invalid(code))
return luaL_error(L, "invalid UTF-8 code");
lua_pushinteger(L, p-s+1);
lua_pushinteger(L, code);
return 2;
}
return 0; /* no more codepoints */
}
static int iter_auxstrict (lua_State *L) { return iter_aux(L, 1); }
static int iter_auxlax (lua_State *L) { return iter_aux(L, 0); }
static int Lutf8_codes (lua_State *L) {
int lax = lua_toboolean(L, 2);
luaL_checkstring(L, 1);
lua_pushcfunction(L, lax ? iter_auxlax : iter_auxstrict);
lua_pushvalue(L, 1);
lua_pushinteger(L, 0);
return 3;
}
static int Lutf8_width (lua_State *L) {
int t = lua_type(L, 1);
int ambi_is_single = !lua_toboolean(L, 2);
int default_width = CAST(int, luaL_optinteger(L, 3, 0));
if (t == LUA_TNUMBER) {
size_t chwidth = utf8_width(CAST(utfint, lua_tointeger(L, 1)), ambi_is_single);
if (chwidth == 0) chwidth = default_width;
lua_pushinteger(L, (lua_Integer)chwidth);
} else if (t != LUA_TSTRING)
return typeerror(L, 1, "number/string");
else {
const char *e, *s = to_utf8(L, 1, &e);
int width = 0;
while (s < e) {
utfint ch = 0;
int chwidth;
s = utf8_safe_decode(L, s, &ch);
chwidth = utf8_width(ch, ambi_is_single);
width += chwidth == 0 ? default_width : chwidth;
}
lua_pushinteger(L, (lua_Integer)width);
}
return 1;
}
static int Lutf8_widthindex (lua_State *L) {
const char *e, *s = check_utf8(L, 1, &e);
int width = CAST(int, luaL_checkinteger(L, 2));
int ambi_is_single = !lua_toboolean(L, 3);
int default_width = CAST(int, luaL_optinteger(L, 4, 0));
size_t idx = 1;
while (s < e) {
utfint ch = 0;
size_t chwidth;
s = utf8_safe_decode(L, s, &ch);
chwidth = utf8_width(ch, ambi_is_single);
if (chwidth == 0) chwidth = default_width;
width -= CAST(int, chwidth);
if (width <= 0) {
lua_pushinteger(L, idx);
lua_pushinteger(L, width + chwidth);
lua_pushinteger(L, chwidth);
return 3;
}
++idx;
}
lua_pushinteger(L, (lua_Integer)idx);
return 1;
}
static int Lutf8_ncasecmp (lua_State *L) {
const char *e1, *s1 = check_utf8(L, 1, &e1);
const char *e2, *s2 = check_utf8(L, 2, &e2);
while (s1 < e1 || s2 < e2) {
utfint ch1 = 0, ch2 = 0;
if (s1 == e1)
ch2 = 1;
else if (s2 == e2)
ch1 = 1;
else {
s1 = utf8_safe_decode(L, s1, &ch1);
s2 = utf8_safe_decode(L, s2, &ch2);
ch1 = utf8_tofold(ch1);
ch2 = utf8_tofold(ch2);
}
if (ch1 != ch2) {
lua_pushinteger(L, ch1 > ch2 ? 1 : -1);
return 1;
}
}
lua_pushinteger(L, 0);
return 1;
}
/* utf8 pattern matching implement */
#ifndef LUA_MAXCAPTURES
# define LUA_MAXCAPTURES 32
#endif /* LUA_MAXCAPTURES */
#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);
/* 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;
while (--level >= 0)
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) {
utfint ch = 0;
p = utf8_safe_decode(ms->L, p, &ch);
switch (ch) {
case L_ESC: {
if (p == ms->p_end)
luaL_error(ms->L, "malformed pattern (ends with " LUA_QL("%%") ")");
return utf8_next(p, ms->p_end);
}
case '[': {
if (*p == '^') p++;
do { /* look for a `]' */
if (p == ms->p_end)
luaL_error(ms->L, "malformed pattern (missing " LUA_QL("]") ")");
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 (utfint c, utfint cl) {
int res;
switch (utf8_tolower(cl)) {
#define X(cls, name) case cls: res = utf8_is##name(c); break;
utf8_categories(X)
#undef X
case 'g' : res = utf8_isgraph(c); break;
case 'w' : res = utf8_isalnum(c); break;
case 'z' : res = (c == 0); break; /* deprecated option */
default: return (cl == c);
}
return (utf8_islower(cl) ? res : !res);
}
static int matchbracketclass (MatchState *ms, utfint c, const char *p, const char *ec) {
int sig = 1;
assert(*p == '[');
if (*++p == '^') {
sig = 0;
p++; /* skip the `^' */
}
while (p < ec) {
utfint ch = 0;
p = utf8_safe_decode(ms->L, p, &ch);
if (ch == L_ESC) {
p = utf8_safe_decode(ms->L, p, &ch);
if (match_class(c, ch))
return sig;
} else {
utfint next = 0;
const char *np = utf8_safe_decode(ms->L, p, &next);
if (next == '-' && np < ec) {
p = utf8_safe_decode(ms->L, np, &next);
if (ch <= c && c <= next)
return sig;
}
else if (ch == 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 {
utfint ch=0, pch=0;
utf8_safe_decode(ms->L, s, &ch);
p = utf8_safe_decode(ms->L, p, &pch);
switch (pch) {
case '.': return 1; /* matches any char */
case L_ESC: utf8_safe_decode(ms->L, p, &pch);
return match_class(ch, pch);
case '[': return matchbracketclass(ms, ch, p-1, ep-1);
default: return pch == ch;
}
}
}
static const char *matchbalance (MatchState *ms, const char *s, const char **p) {
utfint ch=0, begin=0, end=0;
*p = utf8_safe_decode(ms->L, *p, &begin);
if (*p >= ms->p_end)
luaL_error(ms->L, "malformed pattern "
"(missing arguments to " LUA_QL("%%b") ")");
*p = utf8_safe_decode(ms->L, *p, &end);
s = utf8_safe_decode(ms->L, s, &ch);
if (ch != begin) return NULL;
else {
int cont = 1;
while (s < ms->src_end) {
s = utf8_safe_decode(ms->L, s, &ch);
if (ch == end) {
if (--cont == 0) return s;
}
else if (ch == begin) cont++;
}
}
return NULL; /* string ends out of balance */
}
static const char *max_expand (MatchState *ms, const char *s, const char *p, const char *ep) {
const char *m = s; /* matched end of single match p */
while (singlematch(ms, m, p, ep))
m = utf8_next(m, ms->src_end);
/* keeps trying to match with the maximum repetitions */
while (s <= m) {
const char *res = match(ms, m, ep+1);
if (res) return res;
/* else didn't match; reduce 1 repetition to try again */
if (s == m) break;
m = utf8_prev(s, m);
}
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 = utf8_next(s, ms->src_end); /* 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? */
utfint ch = 0;
utf8_safe_decode(ms->L, p, &ch);
switch (ch) {
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 sequence not in the format class[*+?-]? */
const char *prev_p = p;
p = utf8_safe_decode(ms->L, p+1, &ch);
switch (ch) {
case 'b': { /* balanced string? */
s = matchbalance(ms, s, &p);
if (s != NULL)
goto init; /* return match(ms, s, p + 4); */
/* else fail (s == NULL) */
break;
}
case 'f': { /* frontier? */
const char *ep; utfint previous = 0, current = 0;
if (*p != '[')
luaL_error(ms->L, "missing " LUA_QL("[") " after "
LUA_QL("%%f") " in pattern");
ep = classend(ms, p); /* points to what is next */
if (s != ms->src_init)
utf8_decode(utf8_prev(ms->src_init, s), &previous, 0);
if (s != ms->src_end)
utf8_decode(s, &current, 0);
if (!matchbracketclass(ms, previous, p, ep - 1) &&
matchbracketclass(ms, current, 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, ch);
if (s != NULL) goto init; /* return match(ms, s, p + 2) */
break;
}
default: p = prev_p; 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 */
const char *next_s = utf8_next(s, ms->src_end);
switch (*ep) { /* handle optional suffix */
case '?': { /* optional */
const char *res;
const char *next_ep = utf8_next(ep, ms->p_end);
if ((res = match(ms, next_s, next_ep)) != NULL)
s = res;
else {
p = next_ep; goto init; /* else return match(ms, s, ep + 1); */
}
break;
}
case '+': /* 1 or more repetitions */
s = next_s; /* 1 match already done */
/* fall 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 = next_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 int get_index (const char *p, const char *s, const char *e) {
int idx;
for (idx = 0; s < e && s < p; ++idx)
s = utf8_next(s, e);
return s == p ? idx : idx - 1;
}
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) {
int idx = get_index(ms->capture[i].init, ms->src_init, ms->src_end);
lua_pushinteger(ms->L, idx+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, const char * ep) {
while (p < ep) {
if (strpbrk(p, SPECIALS))
return 0; /* pattern has a special character */
p += strlen(p) + 1; /* may have more after \0 */
}
return 1; /* no special chars found */
}
/* utf8 pattern matching interface */
static int find_aux (lua_State *L, int find) {
const char *es, *s = check_utf8(L, 1, &es);
const char *ep, *p = check_utf8(L, 2, &ep);
lua_Integer idx = luaL_optinteger(L, 3, 1);
const char *init;
if (!idx) idx = 1;
init = utf8_relat(s, es, CAST(int, idx));
if (init == NULL) {
if (idx > 0) {
lua_pushnil(L); /* cannot find anything */
return 1;
}
init = s;
}
/* explicit request or no special characters? */
if (find && (lua_toboolean(L, 4) || nospecials(p, ep))) {
/* do a plain search */
const char *s2 = lmemfind(init, es-init, p, ep-p);
if (s2) {
const char *e2 = s2 + (ep - p);
if (iscont(e2)) e2 = utf8_next(e2, es);
lua_pushinteger(L, idx = get_index(s2, s, es) + 1);
lua_pushinteger(L, idx + get_index(e2, s2, es) - 1);
return 2;
}
} else {
MatchState ms;
int anchor = (*p == '^');
if (anchor) p++; /* skip anchor character */
if (idx < 0) idx += utf8_length(s, es)+1; /* TODO not very good */
ms.L = L;
ms.matchdepth = MAXCCALLS;
ms.src_init = s;
ms.src_end = es;
ms.p_end = ep;
do {
const char *res;
ms.level = 0;
assert(ms.matchdepth == MAXCCALLS);
if ((res=match(&ms, init, p)) != NULL) {
if (find) {
lua_pushinteger(L, idx); /* start */
lua_pushinteger(L, idx + utf8_length(init, res) - 1); /* end */
return push_captures(&ms, NULL, 0) + 2;
} else
return push_captures(&ms, init, res);
}
if (init == es) break;
idx += 1;
init = utf8_next(init, es);
} while (init <= es && !anchor);
}
lua_pushnil(L); /* not found */
return 1;
}
static int Lutf8_find (lua_State *L) { return find_aux(L, 1); }
static int Lutf8_match (lua_State *L) { return find_aux(L, 0); }
static int gmatch_aux (lua_State *L) {
MatchState ms;
const char *es, *s = check_utf8(L, lua_upvalueindex(1), &es);
const char *ep, *p = check_utf8(L, lua_upvalueindex(2), &ep);
const char *src;
ms.L = L;
ms.matchdepth = MAXCCALLS;
ms.src_init = s;
ms.src_end = es;
ms.p_end = ep;
for (src = s + (size_t)lua_tointeger(L, lua_upvalueindex(3));
src <= ms.src_end;
src = utf8_next(src, ms.src_end)) {
const char *e;
ms.level = 0;
assert(ms.matchdepth == MAXCCALLS);
if ((e = match(&ms, src, p)) != NULL) {
lua_Integer newstart = 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);
}
if (src == ms.src_end) break;
}
return 0; /* not found */
}
static int Lutf8_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, 3);
return 1;
}
static void add_s (MatchState *ms, luaL_Buffer *b, const char *s, const char *e) {
const char *new_end, *news = to_utf8(ms->L, 3, &new_end);
while (news < new_end) {
utfint ch = 0;
news = utf8_safe_decode(ms->L, news, &ch);
if (ch != L_ESC)
add_utf8char(b, ch);
else {
news = utf8_safe_decode(ms->L, news, &ch); /* skip ESC */
if (!utf8_isdigit(ch)) {
if (ch != L_ESC)
luaL_error(ms->L, "invalid use of " LUA_QL("%c")
" in replacement string", L_ESC);
add_utf8char(b, ch);
} else if (ch == '0')
luaL_addlstring(b, s, e-s);
else {
push_onecapture(ms, ch-'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 Lutf8_gsub (lua_State *L) {
const char *es, *s = check_utf8(L, 1, &es);
const char *ep, *p = check_utf8(L, 2, &ep);
int tr = lua_type(L, 3);
lua_Integer max_s = luaL_optinteger(L, 4, (es-s)+1);
int anchor = (*p == '^');
lua_Integer n = 0;
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++; /* skip anchor character */
ms.L = L;
ms.matchdepth = MAXCCALLS;
ms.src_init = s;
ms.src_end = es;
ms.p_end = ep;
while (n < max_s) {
const char *e;
ms.level = 0;
assert(ms.matchdepth == MAXCCALLS);
e = match(&ms, s, p);
if (e) {
n++;
add_value(&ms, &b, s, e, tr);
}
if (e && e > s) /* non empty match? */
s = e; /* skip it */
else if (s < es) {
utfint ch = 0;
s = utf8_safe_decode(L, s, &ch);
add_utf8char(&b, ch);
} else break;
if (anchor) break;
}
luaL_addlstring(&b, s, es-s);
luaL_pushresult(&b);
lua_pushinteger(L, n); /* number of substitutions */
return 2;
}
/* lua module import interface */
#if LUA_VERSION_NUM >= 502
static const char UTF8PATT[] = "[\0-\x7F\xC2-\xF4][\x80-\xBF]*";
#else
static const char UTF8PATT[] = "[%z\1-\x7F\xC2-\xF4][\x80-\xBF]*";
#endif
int luaopen_utf8extra (lua_State *L) {
luaL_Reg libs[] = {
#define ENTRY(name) { #name, Lutf8_##name }
ENTRY(offset),
ENTRY(codes),
ENTRY(codepoint),
ENTRY(len),
ENTRY(sub),
ENTRY(reverse),
ENTRY(lower),
ENTRY(upper),
ENTRY(title),
ENTRY(fold),
ENTRY(byte),
ENTRY(char),
ENTRY(escape),
ENTRY(insert),
ENTRY(remove),
ENTRY(charpos),
ENTRY(next),
ENTRY(width),
ENTRY(widthindex),
ENTRY(ncasecmp),
ENTRY(find),
ENTRY(gmatch),
ENTRY(gsub),
ENTRY(match),
#undef ENTRY
{ NULL, NULL }
};
luaL_newlib(L, libs);
lua_pushlstring(L, UTF8PATT, sizeof(UTF8PATT)-1);
lua_setfield(L, -2, "charpattern");
return 1;
}