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/*
* Copyright (c) 2015 Isode Limited.
* All rights reserved.
* See the COPYING file for more information.
*/
#pragma once
#include <cstddef>
namespace Swift {
// UTF-8 validation based on the description in https://tools.ietf.org/html/rfc3629#section-3 .
template <typename CharType>
bool UTF8IsValid(const CharType* data, size_t length) {
bool isValid = true;
const CharType* current = data;
const CharType* end = data + length;
while (isValid && (current < end)) {
// one byte sequences
if ((*current & 0x80) == 0x0) {
current++;
continue;
}
// longer byte sequences
else {
// two byte sequences
if ((*current & 0xE0) == 0xC0) {
current++;
if ( (current < end) && ((*current & 0xC0) == 0x80) ) {
current++;
continue;
}
}
// three byte sequences
else if ((*current & 0xF0) == 0xE0) {
current++;
if ( ((current + 1) < end) && ((*current & 0xC0) == 0x80) ) {
current++;
if ((*current & 0xC0) == 0x80) {
current++;
continue;
}
}
}
// four byte sequences
else if ((*current & 0xF8) == 0xF0) {
current++;
if ( ((current + 2) < end) && ((*current & 0xC0) == 0x80) ) {
current++;
if ((*current & 0xC0) == 0x80) {
current++;
if ((*current & 0xC0) == 0x80) {
current++;
continue;
}
}
}
}
// invalid sequences
isValid = false;
}
}
return isValid;
}
}
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Swift