vendor/utfcpp/utf8/unchecked.h

   1 // Copyright 2006 Nemanja Trifunovic
   2
   3 /*
   4 Permission is hereby granted, free of charge, to any person or organization
   5 obtaining a copy of the software and accompanying documentation covered by
   6 this license (the "Software") to use, reproduce, display, distribute,
   7 execute, and transmit the Software, and to prepare derivative works of the
   8 Software, and to permit third-parties to whom the Software is furnished to
   9 do so, all subject to the following:
  10
  11 The copyright notices in the Software and this entire statement, including
  12 the above license grant, this restriction and the following disclaimer,
  13 must be included in all copies of the Software, in whole or in part, and
  14 all derivative works of the Software, unless such copies or derivative
  15 works are solely in the form of machine-executable object code generated by
  16 a source language processor.
  17
  18 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  19 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  20 FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT
  21 SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE
  22 FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE,
  23 ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  24 DEALINGS IN THE SOFTWARE.
  25 */
  26
  27
  28 #ifndef UTF8_FOR_CPP_UNCHECKED_H_2675DCD0_9480_4c0c_B92A_CC14C027B731
  29 #define UTF8_FOR_CPP_UNCHECKED_H_2675DCD0_9480_4c0c_B92A_CC14C027B731
  30
  31 #include "core.h"
  32
  33 namespace utf8
  34 {
  35     namespace unchecked
  36     {
  37         template <typename octet_iterator>
  38         octet_iterator append(uint32_t cp, octet_iterator result)
  39         {
  40             if (cp < 0x80)                        // one octet
  41                 *(result++) = static_cast<uint8_t>(cp);
  42             else if (cp < 0x800) {                // two octets
  43                 *(result++) = static_cast<uint8_t>((cp >> 6)          | 0xc0);
  44                 *(result++) = static_cast<uint8_t>((cp & 0x3f)        | 0x80);
  45             }
  46             else if (cp < 0x10000) {              // three octets
  47                 *(result++) = static_cast<uint8_t>((cp >> 12)         | 0xe0);
  48                 *(result++) = static_cast<uint8_t>(((cp >> 6) & 0x3f) | 0x80);
  49                 *(result++) = static_cast<uint8_t>((cp & 0x3f)        | 0x80);
  50             }
  51             else {                                // four octets
  52                 *(result++) = static_cast<uint8_t>((cp >> 18)         | 0xf0);
  53                 *(result++) = static_cast<uint8_t>(((cp >> 12) & 0x3f)| 0x80);
  54                 *(result++) = static_cast<uint8_t>(((cp >> 6) & 0x3f) | 0x80);
  55                 *(result++) = static_cast<uint8_t>((cp & 0x3f)        | 0x80);
  56             }
  57             return result;
  58         }
  59
  60         template <typename octet_iterator, typename output_iterator>
  61         output_iterator replace_invalid(octet_iterator start, octet_iterator end, output_iterator out, uint32_t replacement)
  62         {
  63             while (start != end) {
  64                 octet_iterator sequence_start = start;
  65                 internal::utf_error err_code = utf8::internal::validate_next(start, end);
  66                 switch (err_code) {
  67                     case internal::UTF8_OK :
  68                         for (octet_iterator it = sequence_start; it != start; ++it)
  69                             *out++ = *it;
  70                         break;
  71                     case internal::NOT_ENOUGH_ROOM:
  72                         out = utf8::unchecked::append (replacement, out);
  73                         start = end;
  74                         break;
  75                     case internal::INVALID_LEAD:
  76                         out = utf8::unchecked::append (replacement, out);
  77                         ++start;
  78                         break;
  79                     case internal::INCOMPLETE_SEQUENCE:
  80                     case internal::OVERLONG_SEQUENCE:
  81                     case internal::INVALID_CODE_POINT:
  82                         out = utf8::unchecked::append (replacement, out);
  83                         ++start;
  84                         // just one replacement mark for the sequence
  85                         while (start != end && utf8::internal::is_trail(*start))
  86                             ++start;
  87                         break;
  88                 }
  89             }
  90             return out;
  91         }
  92
  93         template <typename octet_iterator, typename output_iterator>
  94         inline output_iterator replace_invalid(octet_iterator start, octet_iterator end, output_iterator out)
  95         {
  96             static const uint32_t replacement_marker = utf8::internal::mask16(0xfffd);
  97             return utf8::unchecked::replace_invalid(start, end, out, replacement_marker);
  98         }
  99
 100         template <typename octet_iterator>
 101         uint32_t next(octet_iterator& it)
 102         {
 103             uint32_t cp = utf8::internal::mask8(*it);
 104             typename std::iterator_traits<octet_iterator>::difference_type length = utf8::internal::sequence_length(it);
 105             switch (length) {
 106                 case 1:
 107                     break;
 108                 case 2:
 109                     it++;
 110                     cp = ((cp << 6) & 0x7ff) + ((*it) & 0x3f);
 111                     break;
 112                 case 3:
 113                     ++it;
 114                     cp = ((cp << 12) & 0xffff) + ((utf8::internal::mask8(*it) << 6) & 0xfff);
 115                     ++it;
 116                     cp += (*it) & 0x3f;
 117                     break;
 118                 case 4:
 119                     ++it;
 120                     cp = ((cp << 18) & 0x1fffff) + ((utf8::internal::mask8(*it) << 12) & 0x3ffff);
 121                     ++it;
 122                     cp += (utf8::internal::mask8(*it) << 6) & 0xfff;
 123                     ++it;
 124                     cp += (*it) & 0x3f;
 125                     break;
 126             }
 127             ++it;
 128             return cp;
 129         }
 130
 131         template <typename octet_iterator>
 132         uint32_t peek_next(octet_iterator it)
 133         {
 134             return utf8::unchecked::next(it);
 135         }
 136
 137         template <typename octet_iterator>
 138         uint32_t prior(octet_iterator& it)
 139         {
 140             while (utf8::internal::is_trail(*(--it))) ;
 141             octet_iterator temp = it;
 142             return utf8::unchecked::next(temp);
 143         }
 144
 145         template <typename octet_iterator, typename distance_type>
 146         void advance (octet_iterator& it, distance_type n)
 147         {
 148             const distance_type zero(0);
 149             if (n < zero) {
 150                 // backward
 151                 for (distance_type i = n; i < zero; ++i)
 152                     utf8::unchecked::prior(it);
 153             } else {
 154                 // forward
 155                 for (distance_type i = zero; i < n; ++i)
 156                     utf8::unchecked::next(it);
 157             }
 158         }
 159
 160         template <typename octet_iterator>
 161         typename std::iterator_traits<octet_iterator>::difference_type
 162         distance (octet_iterator first, octet_iterator last)
 163         {
 164             typename std::iterator_traits<octet_iterator>::difference_type dist;
 165             for (dist = 0; first < last; ++dist)
 166                 utf8::unchecked::next(first);
 167             return dist;
 168         }
 169
 170         template <typename u16bit_iterator, typename octet_iterator>
 171         octet_iterator utf16to8 (u16bit_iterator start, u16bit_iterator end, octet_iterator result)
 172         {
 173             while (start != end) {
 174                 uint32_t cp = utf8::internal::mask16(*start++);
 175             // Take care of surrogate pairs first
 176                 if (utf8::internal::is_lead_surrogate(cp)) {
 177                     uint32_t trail_surrogate = utf8::internal::mask16(*start++);
 178                     cp = (cp << 10) + trail_surrogate + internal::SURROGATE_OFFSET;
 179                 }
 180                 result = utf8::unchecked::append(cp, result);
 181             }
 182             return result;
 183         }
 184
 185         template <typename u16bit_iterator, typename octet_iterator>
 186         u16bit_iterator utf8to16 (octet_iterator start, octet_iterator end, u16bit_iterator result)
 187         {
 188             while (start < end) {
 189                 uint32_t cp = utf8::unchecked::next(start);
 190                 if (cp > 0xffff) { //make a surrogate pair
 191                     *result++ = static_cast<uint16_t>((cp >> 10)   + internal::LEAD_OFFSET);
 192                     *result++ = static_cast<uint16_t>((cp & 0x3ff) + internal::TRAIL_SURROGATE_MIN);
 193                 }
 194                 else
 195                     *result++ = static_cast<uint16_t>(cp);
 196             }
 197             return result;
 198         }
 199
 200         template <typename octet_iterator, typename u32bit_iterator>
 201         octet_iterator utf32to8 (u32bit_iterator start, u32bit_iterator end, octet_iterator result)
 202         {
 203             while (start != end)
 204                 result = utf8::unchecked::append(*(start++), result);
 205
 206             return result;
 207         }
 208
 209         template <typename octet_iterator, typename u32bit_iterator>
 210         u32bit_iterator utf8to32 (octet_iterator start, octet_iterator end, u32bit_iterator result)
 211         {
 212             while (start < end)
 213                 (*result++) = utf8::unchecked::next(start);
 214
 215             return result;
 216         }
 217
 218         // The iterator class
 219         template <typename octet_iterator>
 220           class iterator : public std::iterator <std::bidirectional_iterator_tag, uint32_t> {
 221             octet_iterator it;
 222             public:
 223             iterator () {}
 224             explicit iterator (const octet_iterator& octet_it): it(octet_it) {}
 225             // the default "big three" are OK
 226             octet_iterator base () const { return it; }
 227             uint32_t operator * () const
 228             {
 229                 octet_iterator temp = it;
 230                 return utf8::unchecked::next(temp);
 231             }
 232             bool operator == (const iterator& rhs) const
 233             {
 234                 return (it == rhs.it);
 235             }
 236             bool operator != (const iterator& rhs) const
 237             {
 238                 return !(operator == (rhs));
 239             }
 240             iterator& operator ++ ()
 241             {
 242                 ::std::advance(it, utf8::internal::sequence_length(it));
 243                 return *this;
 244             }
 245             iterator operator ++ (int)
 246             {
 247                 iterator temp = *this;
 248                 ::std::advance(it, utf8::internal::sequence_length(it));
 249                 return temp;
 250             }
 251             iterator& operator -- ()
 252             {
 253                 utf8::unchecked::prior(it);
 254                 return *this;
 255             }
 256             iterator operator -- (int)
 257             {
 258                 iterator temp = *this;
 259                 utf8::unchecked::prior(it);
 260                 return temp;
 261             }
 262           }; // class iterator
 263
 264     } // namespace utf8::unchecked
 265 } // namespace utf8
 266
 267
 268 #endif // header guard
 269