dep/include/utf8cpp/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>
  61         uint32_t next(octet_iterator& it)
  62         {
  63             uint32_t cp = internal::mask8(*it);
  64             typename std::iterator_traits<octet_iterator>::difference_type length = utf8::internal::sequence_length(it);
  65             switch (length) {
  66                 case 1:
  67                     break;
  68                 case 2:
  69                     it++;
  70                     cp = ((cp << 6) & 0x7ff) + ((*it) & 0x3f);
  71                     break;
  72                 case 3:
  73                     ++it;
  74                     cp = ((cp << 12) & 0xffff) + ((internal::mask8(*it) << 6) & 0xfff);
  75                     ++it;
  76                     cp += (*it) & 0x3f;
  77                     break;
  78                 case 4:
  79                     ++it;
  80                     cp = ((cp << 18) & 0x1fffff) + ((internal::mask8(*it) << 12) & 0x3ffff);
  81                     ++it;
  82                     cp += (internal::mask8(*it) << 6) & 0xfff;
  83                     ++it;
  84                     cp += (*it) & 0x3f;
  85                     break;
  86             }
  87             ++it;
  88             return cp;
  89         }
  90
  91         template <typename octet_iterator>
  92         uint32_t peek_next(octet_iterator it)
  93         {
  94             return next(it);
  95         }
  96
  97         template <typename octet_iterator>
  98         uint32_t prior(octet_iterator& it)
  99         {
 100             while (internal::is_trail(*(--it))) ;
 101             octet_iterator temp = it;
 102             return next(temp);
 103         }
 104
 105         // Deprecated in versions that include prior, but only for the sake of consistency (see utf8::previous)
 106         template <typename octet_iterator>
 107         inline uint32_t previous(octet_iterator& it)
 108         {
 109             return prior(it);
 110         }
 111
 112         template <typename octet_iterator, typename distance_type>
 113         void advance (octet_iterator& it, distance_type n)
 114         {
 115             for (distance_type i = 0; i < n; ++i)
 116                 next(it);
 117         }
 118
 119         template <typename octet_iterator>
 120         typename std::iterator_traits<octet_iterator>::difference_type
 121         distance (octet_iterator first, octet_iterator last)
 122         {
 123             typename std::iterator_traits<octet_iterator>::difference_type dist;
 124             for (dist = 0; first < last; ++dist)
 125                 next(first);
 126             return dist;
 127         }
 128
 129         template <typename u16bit_iterator, typename octet_iterator>
 130         octet_iterator utf16to8 (u16bit_iterator start, u16bit_iterator end, octet_iterator result)
 131         {
 132             while (start != end) {
 133                 uint32_t cp = internal::mask16(*start++);
 134             // Take care of surrogate pairs first
 135                 if (internal::is_surrogate(cp)) {
 136                     uint32_t trail_surrogate = internal::mask16(*start++);
 137                     cp = (cp << 10) + trail_surrogate + internal::SURROGATE_OFFSET;
 138                 }
 139                 result = append(cp, result);
 140             }
 141             return result;
 142         }
 143
 144         template <typename u16bit_iterator, typename octet_iterator>
 145         u16bit_iterator utf8to16 (octet_iterator start, octet_iterator end, u16bit_iterator result)
 146         {
 147             while (start != end) {
 148                 uint32_t cp = next(start);
 149                 if (cp > 0xffff) { //make a surrogate pair
 150                     *result++ = static_cast<uint16_t>((cp >> 10)   + internal::LEAD_OFFSET);
 151                     *result++ = static_cast<uint16_t>((cp & 0x3ff) + internal::TRAIL_SURROGATE_MIN);
 152                 }
 153                 else
 154                     *result++ = static_cast<uint16_t>(cp);
 155             }
 156             return result;
 157         }
 158
 159         template <typename octet_iterator, typename u32bit_iterator>
 160         octet_iterator utf32to8 (u32bit_iterator start, u32bit_iterator end, octet_iterator result)
 161         {
 162             while (start != end)
 163                 result = append(*(start++), result);
 164
 165             return result;
 166         }
 167
 168         template <typename octet_iterator, typename u32bit_iterator>
 169         u32bit_iterator utf8to32 (octet_iterator start, octet_iterator end, u32bit_iterator result)
 170         {
 171             while (start < end)
 172                 (*result++) = next(start);
 173
 174             return result;
 175         }
 176
 177         // The iterator class
 178         template <typename octet_iterator>
 179           class iterator : public std::iterator <std::bidirectional_iterator_tag, uint32_t> {
 180             octet_iterator it;
 181             public:
 182             iterator () {};
 183             explicit iterator (const octet_iterator& octet_it): it(octet_it) {}
 184             // the default "big three" are OK
 185             octet_iterator base () const { return it; }
 186             uint32_t operator * () const
 187             {
 188                 octet_iterator temp = it;
 189                 return next(temp);
 190             }
 191             bool operator == (const iterator& rhs) const
 192             {
 193                 return (it == rhs.it);
 194             }
 195             bool operator != (const iterator& rhs) const
 196             {
 197                 return !(operator == (rhs));
 198             }
 199             iterator& operator ++ ()
 200             {
 201                 std::advance(it, internal::sequence_length(it));
 202                 return *this;
 203             }
 204             iterator operator ++ (int)
 205             {
 206                 iterator temp = *this;
 207                 std::advance(it, internal::sequence_length(it));
 208                 return temp;
 209             }
 210             iterator& operator -- ()
 211             {
 212                 prior(it);
 213                 return *this;
 214             }
 215             iterator operator -- (int)
 216             {
 217                 iterator temp = *this;
 218                 prior(it);
 219                 return temp;
 220             }
 221           }; // class iterator
 222
 223     } // namespace utf8::unchecked
 224 } // namespace utf8
 225
 226
 227 #endif // header guard
 228