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-rw-r--r--src/lib/lualib/lutf8lib.c256
1 files changed, 256 insertions, 0 deletions
diff --git a/src/lib/lualib/lutf8lib.c b/src/lib/lualib/lutf8lib.c
new file mode 100644
index 0000000..9042582
--- /dev/null
+++ b/src/lib/lualib/lutf8lib.c
@@ -0,0 +1,256 @@
+/*
+** $Id: lutf8lib.c,v 1.15 2015/03/28 19:16:55 roberto Exp $
+** 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"
+
+#define MAXUNICODE 0x10FFFF
+
+#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;
+}
+
+
+/*
+** Decode one UTF-8 sequence, returning NULL if byte sequence is invalid.
+*/
+static const char *utf8_decode (const char *o, int *val) {
+ static const unsigned int limits[] = {0xFF, 0x7F, 0x7FF, 0xFFFF};
+ const unsigned char *s = (const unsigned char *)o;
+ unsigned int c = s[0];
+ unsigned int res = 0; /* final result */
+ if (c < 0x80) /* ascii? */
+ res = c;
+ else {
+ int count = 0; /* to count number of continuation bytes */
+ while (c & 0x40) { /* still have continuation bytes? */
+ int cc = 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 */
+ c <<= 1; /* to test next bit */
+ }
+ res |= ((c & 0x7F) << (count * 5)); /* add first byte */
+ if (count > 3 || res > MAXUNICODE || res <= limits[count])
+ return NULL; /* invalid byte sequence */
+ s += count; /* skip continuation bytes read */
+ }
+ if (val) *val = res;
+ return (const char *)s + 1; /* +1 to include first byte */
+}
+
+
+/*
+** utf8len(s [, i [, j]]) --> number of characters that start in the
+** range [i,j], or nil + current position if 's' is not well formed in
+** that interval
+*/
+static int utflen (lua_State *L) {
+ int n = 0;
+ size_t len;
+ 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);
+ luaL_argcheck(L, 1 <= posi && --posi <= (lua_Integer)len, 2,
+ "initial position out of string");
+ luaL_argcheck(L, --posj < (lua_Integer)len, 3,
+ "final position out of string");
+ while (posi <= posj) {
+ const char *s1 = utf8_decode(s + posi, NULL);
+ if (s1 == NULL) { /* conversion error? */
+ lua_pushnil(L); /* return nil ... */
+ lua_pushinteger(L, posi + 1); /* ... and current position */
+ return 2;
+ }
+ posi = s1 - s;
+ n++;
+ }
+ lua_pushinteger(L, n);
+ return 1;
+}
+
+
+/*
+** codepoint(s, [i, [j]]) -> returns codepoints for all characters
+** that start in the range [i,j]
+*/
+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);
+ 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;
+ se = s + pose;
+ for (s += posi - 1; s < se;) {
+ int code;
+ s = utf8_decode(s, &code);
+ 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) {
+ lua_Integer code = luaL_checkinteger(L, arg);
+ luaL_argcheck(L, 0 <= code && code <= MAXUNICODE, arg, "value out of range");
+ 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,
+ "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))
+ 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 iter_aux (lua_State *L) {
+ 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 {
+ int code;
+ const char *next = utf8_decode(s + n, &code);
+ if (next == NULL || iscont(next))
+ return luaL_error(L, "invalid UTF-8 code");
+ lua_pushinteger(L, n + 1);
+ lua_pushinteger(L, code);
+ return 2;
+ }
+}
+
+
+static int iter_codes (lua_State *L) {
+ luaL_checkstring(L, 1);
+ lua_pushcfunction(L, iter_aux);
+ lua_pushvalue(L, 1);
+ lua_pushinteger(L, 0);
+ return 3;
+}
+
+
+/* pattern to match a single UTF-8 character */
+#define UTF8PATT "[\0-\x7F\xC2-\xF4][\x80-\xBF]*"
+
+
+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;
+}
+
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