Drizzled Public API Documentation

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 #pragma once
29 
30 #include <drizzled/utf8/core.h>
31 
32 namespace drizzled
33 {
34 namespace utf8
35 {
36  namespace unchecked
37  {
38  template <typename octet_iterator>
39  octet_iterator append(uint32_t cp, octet_iterator result)
40  {
41  if (cp < 0x80) // one octet
42  *(result++) = static_cast<uint8_t>(cp);
43  else if (cp < 0x800) { // two octets
44  *(result++) = static_cast<uint8_t>((cp >> 6) | 0xc0);
45  *(result++) = static_cast<uint8_t>((cp & 0x3f) | 0x80);
46  }
47  else if (cp < 0x10000) { // three octets
48  *(result++) = static_cast<uint8_t>((cp >> 12) | 0xe0);
49  *(result++) = static_cast<uint8_t>(((cp >> 6) & 0x3f) | 0x80);
50  *(result++) = static_cast<uint8_t>((cp & 0x3f) | 0x80);
51  }
52  else { // four octets
53  *(result++) = static_cast<uint8_t>((cp >> 18) | 0xf0);
54  *(result++) = static_cast<uint8_t>(((cp >> 12) & 0x3f)| 0x80);
55  *(result++) = static_cast<uint8_t>(((cp >> 6) & 0x3f) | 0x80);
56  *(result++) = static_cast<uint8_t>((cp & 0x3f) | 0x80);
57  }
58  return result;
59  }
60 
61  template <typename octet_iterator>
62  uint32_t next(octet_iterator& it)
63  {
64  uint32_t cp = internal::mask8(*it);
65  typename std::iterator_traits<octet_iterator>::difference_type length = utf8::internal::sequence_length(it);
66  switch (length) {
67  case 1:
68  break;
69  case 2:
70  it++;
71  cp = ((cp << 6) & 0x7ff) + ((*it) & 0x3f);
72  break;
73  case 3:
74  ++it;
75  cp = ((cp << 12) & 0xffff) + ((internal::mask8(*it) << 6) & 0xfff);
76  ++it;
77  cp += (*it) & 0x3f;
78  break;
79  case 4:
80  ++it;
81  cp = ((cp << 18) & 0x1fffff) + ((internal::mask8(*it) << 12) & 0x3ffff);
82  ++it;
83  cp += (internal::mask8(*it) << 6) & 0xfff;
84  ++it;
85  cp += (*it) & 0x3f;
86  break;
87  }
88  ++it;
89  return cp;
90  }
91 
92  template <typename octet_iterator>
93  uint32_t peek_next(octet_iterator it)
94  {
95  return next(it);
96  }
97 
98  template <typename octet_iterator>
99  uint32_t prior(octet_iterator& it)
100  {
101  while (internal::is_trail(*(--it))) ;
102  octet_iterator temp = it;
103  return next(temp);
104  }
105 
106  // Deprecated in versions that include prior, but only for the sake of consistency (see utf8::previous)
107  template <typename octet_iterator>
108  inline uint32_t previous(octet_iterator& it)
109  {
110  return prior(it);
111  }
112 
113  template <typename octet_iterator, typename distance_type>
114  void advance (octet_iterator& it, distance_type n)
115  {
116  for (distance_type i = 0; i < n; ++i)
117  next(it);
118  }
119 
120  template <typename octet_iterator>
121  typename std::iterator_traits<octet_iterator>::difference_type
122  distance (octet_iterator first, octet_iterator last)
123  {
124  typename std::iterator_traits<octet_iterator>::difference_type dist;
125  for (dist = 0; first < last; ++dist)
126  next(first);
127  return dist;
128  }
129 
130  template <typename u16bit_iterator, typename octet_iterator>
131  octet_iterator utf16to8 (u16bit_iterator start, u16bit_iterator end, octet_iterator result)
132  {
133  while (start != end) {
134  uint32_t cp = internal::mask16(*start++);
135  // Take care of surrogate pairs first
136  if (internal::is_lead_surrogate(cp)) {
137  uint32_t trail_surrogate = internal::mask16(*start++);
138  cp = (cp << 10) + trail_surrogate + internal::SURROGATE_OFFSET;
139  }
140  result = append(cp, result);
141  }
142  return result;
143  }
144 
145  template <typename u16bit_iterator, typename octet_iterator>
146  u16bit_iterator utf8to16 (octet_iterator start, octet_iterator end, u16bit_iterator result)
147  {
148  while (start < end) {
149  uint32_t cp = next(start);
150  if (cp > 0xffff) { //make a surrogate pair
151  *result++ = static_cast<uint16_t>((cp >> 10) + internal::LEAD_OFFSET);
152  *result++ = static_cast<uint16_t>((cp & 0x3ff) + internal::TRAIL_SURROGATE_MIN);
153  }
154  else
155  *result++ = static_cast<uint16_t>(cp);
156  }
157  return result;
158  }
159 
160  template <typename octet_iterator, typename u32bit_iterator>
161  octet_iterator utf32to8 (u32bit_iterator start, u32bit_iterator end, octet_iterator result)
162  {
163  while (start != end)
164  result = append(*(start++), result);
165 
166  return result;
167  }
168 
169  template <typename octet_iterator, typename u32bit_iterator>
170  u32bit_iterator utf8to32 (octet_iterator start, octet_iterator end, u32bit_iterator result)
171  {
172  while (start < end)
173  (*result++) = next(start);
174 
175  return result;
176  }
177 
178  // The iterator class
179  template <typename octet_iterator>
180  class iterator : public std::iterator <std::bidirectional_iterator_tag, uint32_t> {
181  octet_iterator it;
182  public:
183  iterator () {};
184  explicit iterator (const octet_iterator& octet_it): it(octet_it) {}
185  // the default "big three" are OK
186  octet_iterator base () const { return it; }
187  uint32_t operator * () const
188  {
189  octet_iterator temp = it;
190  return next(temp);
191  }
192  bool operator == (const iterator& rhs) const
193  {
194  return (it == rhs.it);
195  }
196  bool operator != (const iterator& rhs) const
197  {
198  return !(operator == (rhs));
199  }
200  iterator& operator ++ ()
201  {
202  std::advance(it, internal::sequence_length(it));
203  return *this;
204  }
205  iterator operator ++ (int)
206  {
207  iterator temp = *this;
208  std::advance(it, internal::sequence_length(it));
209  return temp;
210  }
211  iterator& operator -- ()
212  {
213  prior(it);
214  return *this;
215  }
216  iterator operator -- (int)
217  {
218  iterator temp = *this;
219  prior(it);
220  return temp;
221  }
222  }; // class iterator
223 
224  } // namespace utf8::unchecked
225 } // namespace utf8
226 } // namespace drizzled
227 
228 
229