blockchain/src/common/utf8/unchecked.h
2025-09-30 16:48:13 +01:00

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// Copyright (c) 2014-2018 Zano Project
// Copyright (c) 2014-2018 The Louisdor Project
// Copyright (c) 2012-2013 The Boolberry developers
// Copyright (c) 2017-2025 Lethean (https://lt.hn)
//
// Licensed under the European Union Public Licence (EUPL) version 1.2.
// You may obtain a copy of the licence at:
//
// https://joinup.ec.europa.eu/software/page/eupl/licence-eupl
//
// The EUPL is a copyleft licence that is compatible with the MIT/X11
// licence used by the original projects; the MIT terms are therefore
// considered “grandfathered” under the EUPL for this code.
//
// SPDXLicenseIdentifier: EUPL-1.2
//
#ifndef UTF8_FOR_CPP_UNCHECKED_H_2675DCD0_9480_4c0c_B92A_CC14C027B731
#define UTF8_FOR_CPP_UNCHECKED_H_2675DCD0_9480_4c0c_B92A_CC14C027B731
#include "core.h"
namespace utf8
{
namespace unchecked
{
template <typename octet_iterator>
octet_iterator append(utfchar32_t cp, octet_iterator result)
{
return internal::append(cp, result);
}
template <typename word_iterator>
word_iterator append16(utfchar32_t cp, word_iterator result)
{
return internal::append16(cp, result);
}
template <typename octet_iterator, typename output_iterator>
output_iterator replace_invalid(octet_iterator start, octet_iterator end, output_iterator out, utfchar32_t replacement)
{
while (start != end) {
octet_iterator sequence_start = start;
internal::utf_error err_code = utf8::internal::validate_next(start, end);
switch (err_code) {
case internal::UTF8_OK :
for (octet_iterator it = sequence_start; it != start; ++it)
*out++ = *it;
break;
case internal::NOT_ENOUGH_ROOM:
out = utf8::unchecked::append(replacement, out);
start = end;
break;
case internal::INVALID_LEAD:
out = utf8::unchecked::append(replacement, out);
++start;
break;
case internal::INCOMPLETE_SEQUENCE:
case internal::OVERLONG_SEQUENCE:
case internal::INVALID_CODE_POINT:
out = utf8::unchecked::append(replacement, out);
++start;
// just one replacement mark for the sequence
while (start != end && utf8::internal::is_trail(*start))
++start;
break;
}
}
return out;
}
template <typename octet_iterator, typename output_iterator>
inline output_iterator replace_invalid(octet_iterator start, octet_iterator end, output_iterator out)
{
static const utfchar32_t replacement_marker = utf8::internal::mask16(0xfffd);
return utf8::unchecked::replace_invalid(start, end, out, replacement_marker);
}
inline std::string replace_invalid(const std::string& s, utfchar32_t replacement)
{
std::string result;
replace_invalid(s.begin(), s.end(), std::back_inserter(result), replacement);
return result;
}
inline std::string replace_invalid(const std::string& s)
{
std::string result;
replace_invalid(s.begin(), s.end(), std::back_inserter(result));
return result;
}
template <typename octet_iterator>
utfchar32_t next(octet_iterator& it)
{
utfchar32_t cp = utf8::internal::mask8(*it);
switch (utf8::internal::sequence_length(it)) {
case 1:
break;
case 2:
it++;
cp = ((cp << 6) & 0x7ff) + ((*it) & 0x3f);
break;
case 3:
++it;
cp = ((cp << 12) & 0xffff) + ((utf8::internal::mask8(*it) << 6) & 0xfff);
++it;
cp = static_cast<utfchar32_t>(cp + ((*it) & 0x3f));
break;
case 4:
++it;
cp = ((cp << 18) & 0x1fffff) + ((utf8::internal::mask8(*it) << 12) & 0x3ffff);
++it;
cp = static_cast<utfchar32_t>(cp + ((utf8::internal::mask8(*it) << 6) & 0xfff));
++it;
cp = static_cast<utfchar32_t>(cp + ((*it) & 0x3f));
break;
}
++it;
return cp;
}
template <typename octet_iterator>
utfchar32_t peek_next(octet_iterator it)
{
return utf8::unchecked::next(it);
}
template <typename word_iterator>
utfchar32_t next16(word_iterator& it)
{
utfchar32_t cp = utf8::internal::mask16(*it++);
if (utf8::internal::is_lead_surrogate(cp))
return (cp << 10) + *it++ + utf8::internal::SURROGATE_OFFSET;
return cp;
}
template <typename octet_iterator>
utfchar32_t prior(octet_iterator& it)
{
while (utf8::internal::is_trail(*(--it))) ;
octet_iterator temp = it;
return utf8::unchecked::next(temp);
}
template <typename octet_iterator, typename distance_type>
void advance(octet_iterator& it, distance_type n)
{
const distance_type zero(0);
if (n < zero) {
// backward
for (distance_type i = n; i < zero; ++i)
utf8::unchecked::prior(it);
} else {
// forward
for (distance_type i = zero; i < n; ++i)
utf8::unchecked::next(it);
}
}
template <typename octet_iterator>
typename std::iterator_traits<octet_iterator>::difference_type
distance(octet_iterator first, octet_iterator last)
{
typename std::iterator_traits<octet_iterator>::difference_type dist;
for (dist = 0; first < last; ++dist)
utf8::unchecked::next(first);
return dist;
}
template <typename u16bit_iterator, typename octet_iterator>
octet_iterator utf16to8(u16bit_iterator start, u16bit_iterator end, octet_iterator result)
{
while (start != end) {
utfchar32_t cp = utf8::internal::mask16(*start++);
// Take care of surrogate pairs first
if (utf8::internal::is_lead_surrogate(cp)) {
if (start == end)
return result;
utfchar32_t trail_surrogate = utf8::internal::mask16(*start++);
cp = (cp << 10) + trail_surrogate + internal::SURROGATE_OFFSET;
}
result = utf8::unchecked::append(cp, result);
}
return result;
}
template <typename u16bit_iterator, typename octet_iterator>
u16bit_iterator utf8to16(octet_iterator start, octet_iterator end, u16bit_iterator result)
{
while (start < end) {
utfchar32_t cp = utf8::unchecked::next(start);
if (cp > 0xffff) { //make a surrogate pair
*result++ = static_cast<utfchar16_t>((cp >> 10) + internal::LEAD_OFFSET);
*result++ = static_cast<utfchar16_t>((cp & 0x3ff) + internal::TRAIL_SURROGATE_MIN);
}
else
*result++ = static_cast<utfchar16_t>(cp);
}
return result;
}
template <typename octet_iterator, typename u32bit_iterator>
octet_iterator utf32to8(u32bit_iterator start, u32bit_iterator end, octet_iterator result)
{
while (start != end)
result = utf8::unchecked::append(*(start++), result);
return result;
}
template <typename octet_iterator, typename u32bit_iterator>
u32bit_iterator utf8to32(octet_iterator start, octet_iterator end, u32bit_iterator result)
{
while (start < end)
(*result++) = utf8::unchecked::next(start);
return result;
}
// The iterator class
template <typename octet_iterator>
class iterator {
octet_iterator it;
public:
typedef utfchar32_t value_type;
typedef utfchar32_t* pointer;
typedef utfchar32_t& reference;
typedef std::ptrdiff_t difference_type;
typedef std::bidirectional_iterator_tag iterator_category;
iterator () {}
explicit iterator (const octet_iterator& octet_it): it(octet_it) {}
// the default "big three" are OK
octet_iterator base () const { return it; }
utfchar32_t operator * () const
{
octet_iterator temp = it;
return utf8::unchecked::next(temp);
}
bool operator == (const iterator& rhs) const
{
return (it == rhs.it);
}
bool operator != (const iterator& rhs) const
{
return !(operator == (rhs));
}
iterator& operator ++ ()
{
::std::advance(it, utf8::internal::sequence_length(it));
return *this;
}
iterator operator ++ (int)
{
iterator temp = *this;
::std::advance(it, utf8::internal::sequence_length(it));
return temp;
}
iterator& operator -- ()
{
utf8::unchecked::prior(it);
return *this;
}
iterator operator -- (int)
{
iterator temp = *this;
utf8::unchecked::prior(it);
return temp;
}
}; // class iterator
} // namespace utf8::unchecked
} // namespace utf8
#endif // header guard