/**
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* UTF-8 utility functions
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*
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* (c) 2010 Steve Bennett <steveb@workware.net.au>
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*
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* See LICENCE for licence details.
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*/
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#include <ctype.h>
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#include <stdlib.h>
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#include <string.h>
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#include <stdio.h>
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#include <assert.h>
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#include "utf8.h"
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/* This one is always implemented */
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int utf8_fromunicode(char *p, unsigned short uc)
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{
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if (uc <= 0x7f) {
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*p = uc;
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return 1;
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}
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else if (uc <= 0x7ff) {
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*p++ = 0xc0 | ((uc & 0x7c0) >> 6);
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*p = 0x80 | (uc & 0x3f);
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return 2;
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}
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else {
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*p++ = 0xe0 | ((uc & 0xf000) >> 12);
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*p++ = 0x80 | ((uc & 0xfc0) >> 6);
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*p = 0x80 | (uc & 0x3f);
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return 3;
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}
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}
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#if defined(JIM_UTF8) && !defined(JIM_BOOTSTRAP)
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int utf8_charlen(int c)
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{
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if ((c & 0x80) == 0) {
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return 1;
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}
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if ((c & 0xe0) == 0xc0) {
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return 2;
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}
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if ((c & 0xf0) == 0xe0) {
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return 3;
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}
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if ((c & 0xf8) == 0xf0) {
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return 4;
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}
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/* Invalid sequence */
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return -1;
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}
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int utf8_strlen(const char *str, int bytelen)
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{
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int charlen = 0;
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if (bytelen < 0) {
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bytelen = strlen(str);
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}
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while (bytelen) {
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int c;
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int l = utf8_tounicode(str, &c);
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charlen++;
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str += l;
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bytelen -= l;
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}
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return charlen;
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}
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int utf8_index(const char *str, int index)
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{
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const char *s = str;
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while (index--) {
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int c;
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s += utf8_tounicode(s, &c);
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}
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return s - str;
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}
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int utf8_charequal(const char *s1, const char *s2)
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{
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int c1, c2;
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utf8_tounicode(s1, &c1);
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utf8_tounicode(s2, &c2);
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return c1 == c2;
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}
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int utf8_prev_len(const char *str, int len)
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{
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int n = 1;
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assert(len > 0);
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/* Look up to len chars backward for a start-of-char byte */
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while (--len) {
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if ((str[-n] & 0x80) == 0) {
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/* Start of a 1-byte char */
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break;
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}
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if ((str[-n] & 0xc0) == 0xc0) {
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/* Start of a multi-byte char */
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break;
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}
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n++;
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}
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return n;
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}
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int utf8_tounicode(const char *str, int *uc)
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{
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unsigned const char *s = (unsigned const char *)str;
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if (s[0] < 0xc0) {
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*uc = s[0];
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return 1;
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}
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if (s[0] < 0xe0) {
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if ((s[1] & 0xc0) == 0x80) {
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*uc = ((s[0] & ~0xc0) << 6) | (s[1] & ~0x80);
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return 2;
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}
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}
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else if (s[0] < 0xf0) {
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if (((str[1] & 0xc0) == 0x80) && ((str[2] & 0xc0) == 0x80)) {
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*uc = ((s[0] & ~0xe0) << 12) | ((s[1] & ~0x80) << 6) | (s[2] & ~0x80);
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return 3;
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}
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}
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/* Invalid sequence, so just return the byte */
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*uc = *s;
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return 1;
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}
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struct casemap {
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unsigned short code; /* code point */
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signed char lowerdelta; /* add for lowercase, or if -128 use the ext table */
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signed char upperdelta; /* add for uppercase, or offset into the ext table */
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};
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/* Extended table for codepoints where |delta| > 127 */
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struct caseextmap {
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unsigned short lower;
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unsigned short upper;
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};
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/* Generated mapping tables */
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#include "_unicode_mapping.c"
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#define NUMCASEMAP sizeof(unicode_case_mapping) / sizeof(*unicode_case_mapping)
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static int cmp_casemap(const void *key, const void *cm)
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{
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return *(int *)key - (int)((const struct casemap *)cm)->code;
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}
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static int utf8_map_case(int uc, int upper)
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{
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const struct casemap *cm = bsearch(&uc, unicode_case_mapping, NUMCASEMAP, sizeof(*unicode_case_mapping), cmp_casemap);
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if (cm) {
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if (cm->lowerdelta == -128) {
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uc = upper ? unicode_extmap[cm->upperdelta].upper : unicode_extmap[cm->upperdelta].lower;
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}
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else {
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uc += upper ? cm->upperdelta : cm->lowerdelta;
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}
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}
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return uc;
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}
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int utf8_upper(int uc)
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{
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if (isascii(uc)) {
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return toupper(uc);
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}
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return utf8_map_case(uc, 1);
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}
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int utf8_lower(int uc)
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{
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if (isascii(uc)) {
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return tolower(uc);
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}
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return utf8_map_case(uc, 0);
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}
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#endif /* JIM_BOOTSTRAP */
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