259 lines
8.4 KiB
C++
259 lines
8.4 KiB
C++
// Copyright 2006 Nemanja Trifunovic
|
|
|
|
/*
|
|
Permission is hereby granted, free of charge, to any person or organization
|
|
obtaining a copy of the software and accompanying documentation covered by
|
|
this license (the "Software") to use, reproduce, display, distribute,
|
|
execute, and transmit the Software, and to prepare derivative works of the
|
|
Software, and to permit third-parties to whom the Software is furnished to
|
|
do so, all subject to the following:
|
|
|
|
The copyright notices in the Software and this entire statement, including
|
|
the above license grant, this restriction and the following disclaimer,
|
|
must be included in all copies of the Software, in whole or in part, and
|
|
all derivative works of the Software, unless such copies or derivative
|
|
works are solely in the form of machine-executable object code generated by
|
|
a source language processor.
|
|
|
|
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
|
|
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
|
|
FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT
|
|
SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE
|
|
FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE,
|
|
ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
|
|
DEALINGS IN THE SOFTWARE.
|
|
*/
|
|
|
|
|
|
#ifndef UTF8_FOR_CPP_CORE_H_2675DCD0_9480_4c0c_B92A_CC14C027B731
|
|
#define UTF8_FOR_CPP_CORE_H_2675DCD0_9480_4c0c_B92A_CC14C027B731
|
|
|
|
#include <iterator>
|
|
|
|
namespace utf8
|
|
{
|
|
// The typedefs for 8-bit, 16-bit and 32-bit unsigned integers
|
|
// You may need to change them to match your system.
|
|
// These typedefs have the same names as ones from cstdint, or boost/cstdint
|
|
typedef unsigned char uint8_t;
|
|
typedef unsigned short uint16_t;
|
|
typedef unsigned int uint32_t;
|
|
|
|
// Helper code - not intended to be directly called by the library users. May be changed at any time
|
|
namespace internal
|
|
{
|
|
// Unicode constants
|
|
// Leading (high) surrogates: 0xd800 - 0xdbff
|
|
// Trailing (low) surrogates: 0xdc00 - 0xdfff
|
|
const uint16_t LEAD_SURROGATE_MIN = 0xd800u;
|
|
const uint16_t LEAD_SURROGATE_MAX = 0xdbffu;
|
|
const uint16_t TRAIL_SURROGATE_MIN = 0xdc00u;
|
|
const uint16_t TRAIL_SURROGATE_MAX = 0xdfffu;
|
|
const uint16_t LEAD_OFFSET = LEAD_SURROGATE_MIN - (0x10000 >> 10);
|
|
const uint32_t SURROGATE_OFFSET = 0x10000u - (LEAD_SURROGATE_MIN << 10) - TRAIL_SURROGATE_MIN;
|
|
|
|
// Maximum valid value for a Unicode code point
|
|
const uint32_t CODE_POINT_MAX = 0x0010ffffu;
|
|
|
|
template<typename octet_type>
|
|
inline uint8_t mask8(octet_type oc)
|
|
{
|
|
return static_cast<uint8_t>(0xff & oc);
|
|
}
|
|
template<typename u16_type>
|
|
inline uint16_t mask16(u16_type oc)
|
|
{
|
|
return static_cast<uint16_t>(0xffff & oc);
|
|
}
|
|
template<typename octet_type>
|
|
inline bool is_trail(octet_type oc)
|
|
{
|
|
return ((mask8(oc) >> 6) == 0x2);
|
|
}
|
|
|
|
template <typename u16>
|
|
inline bool is_surrogate(u16 cp)
|
|
{
|
|
return (cp >= LEAD_SURROGATE_MIN && cp <= TRAIL_SURROGATE_MAX);
|
|
}
|
|
|
|
template <typename u32>
|
|
inline bool is_code_point_valid(u32 cp)
|
|
{
|
|
return (cp <= CODE_POINT_MAX && !is_surrogate(cp) && cp != 0xfffe && cp != 0xffff);
|
|
}
|
|
|
|
template <typename octet_iterator>
|
|
inline typename std::iterator_traits<octet_iterator>::difference_type
|
|
sequence_length(octet_iterator lead_it)
|
|
{
|
|
uint8_t lead = mask8(*lead_it);
|
|
if (lead < 0x80)
|
|
return 1;
|
|
else if ((lead >> 5) == 0x6)
|
|
return 2;
|
|
else if ((lead >> 4) == 0xe)
|
|
return 3;
|
|
else if ((lead >> 3) == 0x1e)
|
|
return 4;
|
|
else
|
|
return 0;
|
|
}
|
|
|
|
enum utf_error {OK, NOT_ENOUGH_ROOM, INVALID_LEAD, INCOMPLETE_SEQUENCE, OVERLONG_SEQUENCE, INVALID_CODE_POINT};
|
|
|
|
template <typename octet_iterator>
|
|
utf_error validate_next(octet_iterator& it, octet_iterator end, uint32_t* code_point)
|
|
{
|
|
uint32_t cp = mask8(*it);
|
|
// Check the lead octet
|
|
typedef typename std::iterator_traits<octet_iterator>::difference_type octet_difference_type;
|
|
octet_difference_type length = sequence_length(it);
|
|
|
|
// "Shortcut" for ASCII characters
|
|
if (length == 1) {
|
|
if (end - it > 0) {
|
|
if (code_point)
|
|
*code_point = cp;
|
|
++it;
|
|
return OK;
|
|
}
|
|
else
|
|
return NOT_ENOUGH_ROOM;
|
|
}
|
|
|
|
// Do we have enough memory?
|
|
if (std::distance(it, end) < length)
|
|
return NOT_ENOUGH_ROOM;
|
|
|
|
// Check trail octets and calculate the code point
|
|
switch (length) {
|
|
case 0:
|
|
return INVALID_LEAD;
|
|
break;
|
|
case 2:
|
|
if (is_trail(*(++it))) {
|
|
cp = ((cp << 6) & 0x7ff) + ((*it) & 0x3f);
|
|
}
|
|
else {
|
|
--it;
|
|
return INCOMPLETE_SEQUENCE;
|
|
}
|
|
break;
|
|
case 3:
|
|
if (is_trail(*(++it))) {
|
|
cp = ((cp << 12) & 0xffff) + ((mask8(*it) << 6) & 0xfff);
|
|
if (is_trail(*(++it))) {
|
|
cp += (*it) & 0x3f;
|
|
}
|
|
else {
|
|
std::advance(it, -2);
|
|
return INCOMPLETE_SEQUENCE;
|
|
}
|
|
}
|
|
else {
|
|
--it;
|
|
return INCOMPLETE_SEQUENCE;
|
|
}
|
|
break;
|
|
case 4:
|
|
if (is_trail(*(++it))) {
|
|
cp = ((cp << 18) & 0x1fffff) + ((mask8(*it) << 12) & 0x3ffff);
|
|
if (is_trail(*(++it))) {
|
|
cp += (mask8(*it) << 6) & 0xfff;
|
|
if (is_trail(*(++it))) {
|
|
cp += (*it) & 0x3f;
|
|
}
|
|
else {
|
|
std::advance(it, -3);
|
|
return INCOMPLETE_SEQUENCE;
|
|
}
|
|
}
|
|
else {
|
|
std::advance(it, -2);
|
|
return INCOMPLETE_SEQUENCE;
|
|
}
|
|
}
|
|
else {
|
|
--it;
|
|
return INCOMPLETE_SEQUENCE;
|
|
}
|
|
break;
|
|
}
|
|
// Is the code point valid?
|
|
if (!is_code_point_valid(cp)) {
|
|
for (octet_difference_type i = 0; i < length - 1; ++i)
|
|
--it;
|
|
return INVALID_CODE_POINT;
|
|
}
|
|
|
|
if (code_point)
|
|
*code_point = cp;
|
|
|
|
if (cp < 0x80) {
|
|
if (length != 1) {
|
|
std::advance(it, -(length-1));
|
|
return OVERLONG_SEQUENCE;
|
|
}
|
|
}
|
|
else if (cp < 0x800) {
|
|
if (length != 2) {
|
|
std::advance(it, -(length-1));
|
|
return OVERLONG_SEQUENCE;
|
|
}
|
|
}
|
|
else if (cp < 0x10000) {
|
|
if (length != 3) {
|
|
std::advance(it, -(length-1));
|
|
return OVERLONG_SEQUENCE;
|
|
}
|
|
}
|
|
|
|
++it;
|
|
return OK;
|
|
}
|
|
|
|
template <typename octet_iterator>
|
|
inline utf_error validate_next(octet_iterator& it, octet_iterator end) {
|
|
return validate_next(it, end, 0);
|
|
}
|
|
|
|
} // namespace internal
|
|
|
|
/// The library API - functions intended to be called by the users
|
|
|
|
// Byte order mark
|
|
const uint8_t bom[] = {0xef, 0xbb, 0xbf};
|
|
|
|
template <typename octet_iterator>
|
|
octet_iterator find_invalid(octet_iterator start, octet_iterator end)
|
|
{
|
|
octet_iterator result = start;
|
|
while (result != end) {
|
|
internal::utf_error err_code = internal::validate_next(result, end);
|
|
if (err_code != internal::OK)
|
|
return result;
|
|
}
|
|
return result;
|
|
}
|
|
|
|
template <typename octet_iterator>
|
|
inline bool is_valid(octet_iterator start, octet_iterator end)
|
|
{
|
|
return (find_invalid(start, end) == end);
|
|
}
|
|
|
|
template <typename octet_iterator>
|
|
inline bool is_bom (octet_iterator it)
|
|
{
|
|
return (
|
|
(internal::mask8(*it++)) == bom[0] &&
|
|
(internal::mask8(*it++)) == bom[1] &&
|
|
(internal::mask8(*it)) == bom[2]
|
|
);
|
|
}
|
|
} // namespace utf8
|
|
|
|
#endif // header guard
|
|
|
|
|