static size_t PrevCharLength(const char* str) {
for (size_t i = 1; i <= 6; i++) {
str--;
size_t length = NextCharLength(str);
if (length == i) {
return length;
}
}
// Invalid UTF8 string or in the middle of a UTF8 char
return 0;
}
static string TruncateUTF8(const char* str, size_t maxLength) {
string wordTrunc;
if (NotShorterThan(str, maxLength)) {
size_t len = 0;
const char* pStr = str;
while (len < maxLength) {
size_t nextLen = NextCharLength(pStr);
pStr += nextLen;
len += nextLen;
}
wordTrunc = FromSubstr(str, len);
} else {
wordTrunc = str;
}
return wordTrunc;
}
/**
* Truncates a string with a maximal length in byte.
* No UTF8 character will be broken.
*/
static string TruncateUTF8(const char* str, size_t maxByteLength) {
string wordTrunc;
if (NotShorterThan(str, maxByteLength)) {
size_t len = 0;
const char* pStr = str;
for (;;) {
const size_t charLength = NextCharLength(pStr);
if (len + charLength > maxByteLength) {
break;
}
pStr += charLength;
len += charLength;
}
wordTrunc = FromSubstr(str, len);
} else {
wordTrunc = str;
}
return wordTrunc;
}
/**
* Returns the char* pointer over the next UTF8 character.
*/
static const char* NextChar(const char* str) {
return str + NextCharLength(str);
}