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unchecked.h
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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
31 #ifndef UTF8_FOR_CPP_UNCHECKED_H_2675DCD0_9480_4c0c_B92A_CC14C027B731
32 #define UTF8_FOR_CPP_UNCHECKED_H_2675DCD0_9480_4c0c_B92A_CC14C027B731
33
34 #include "core.h"
35
36 namespace utf8
37 {
38 namespace unchecked
39 {
40 template <typename octet_iterator>
41 octet_iterator append(uint32_t cp, octet_iterator result)
42 {
43 if (cp < 0x80) // one octet
44 *(result++) = static_cast<uint8_t>(cp);
45 else if (cp < 0x800) { // two octets
46 *(result++) = static_cast<uint8_t>((cp >> 6) | 0xc0);
47 *(result++) = static_cast<uint8_t>((cp & 0x3f) | 0x80);
48 }
49 else if (cp < 0x10000) { // three octets
50 *(result++) = static_cast<uint8_t>((cp >> 12) | 0xe0);
51 *(result++) = static_cast<uint8_t>((cp >> 6) & 0x3f | 0x80);
52 *(result++) = static_cast<uint8_t>((cp & 0x3f) | 0x80);
53 }
54 else { // four octets
55 *(result++) = static_cast<uint8_t>((cp >> 18) | 0xf0);
56 *(result++) = static_cast<uint8_t>((cp >> 12)& 0x3f | 0x80);
57 *(result++) = static_cast<uint8_t>((cp >> 6) & 0x3f | 0x80);
58 *(result++) = static_cast<uint8_t>((cp & 0x3f) | 0x80);
59 }
60 return result;
61 }
62
63 template <typename octet_iterator>
64 uint32_t next(octet_iterator& it)
65 {
66 uint32_t cp = internal::mask8(*it);
67 typename std::iterator_traits<octet_iterator>::difference_type length = utf8::internal::sequence_length(it);
68 switch (length) {
69 case 1:
70 break;
71 case 2:
72 it++;
73 cp = ((cp << 6) & 0x7ff) + ((*it) & 0x3f);
74 break;
75 case 3:
76 ++it;
77 cp = ((cp << 12) & 0xffff) + ((internal::mask8(*it) << 6) & 0xfff);
78 ++it;
79 cp += (*it) & 0x3f;
80 break;
81 case 4:
82 ++it;
83 cp = ((cp << 18) & 0x1fffff) + ((internal::mask8(*it) << 12) & 0x3ffff);
84 ++it;
85 cp += (internal::mask8(*it) << 6) & 0xfff;
86 ++it;
87 cp += (*it) & 0x3f;
88 break;
89 }
90 ++it;
91 return cp;
92 }
93
94 template <typename octet_iterator>
95 uint32_t peek_next(octet_iterator it)
96 {
97 return next(it);
98 }
99
100 template <typename octet_iterator>
101 uint32_t prior(octet_iterator& it)
102 {
103 while (internal::is_trail(*(--it))) ;
104 octet_iterator temp = it;
105 return next(temp);
106 }
107
108 // Deprecated in versions that include prior, but only for the sake of consistency (see utf8::previous)
109 template <typename octet_iterator>
110 inline uint32_t previous(octet_iterator& it)
111 {
112 return prior(it);
113 }
114
115 template <typename octet_iterator, typename distance_type>
116 void advance (octet_iterator& it, distance_type n)
117 {
118 for (distance_type i = 0; i < n; ++i)
119 next(it);
120 }
121
122 template <typename octet_iterator>
123 typename std::iterator_traits<octet_iterator>::difference_type
124 distance (octet_iterator first, octet_iterator last)
125 {
126 typename std::iterator_traits<octet_iterator>::difference_type dist;
127 for (dist = 0; first < last; ++dist)
128 next(first);
129 return dist;
130 }
131
132 template <typename u16bit_iterator, typename octet_iterator>
133 octet_iterator utf16to8 (u16bit_iterator start, u16bit_iterator end, octet_iterator result)
134 {
135 while (start != end) {
136 uint32_t cp = internal::mask16(*start++);
137 // Take care of surrogate pairs first
138 if (internal::is_surrogate(cp)) {
139 uint32_t trail_surrogate = internal::mask16(*start++);
140 cp = (cp << 10) + trail_surrogate + internal::SURROGATE_OFFSET;
141 }
142 result = append(cp, result);
143 }
144 return result;
145 }
146
147 template <typename u16bit_iterator, typename octet_iterator>
148 u16bit_iterator utf8to16 (octet_iterator start, octet_iterator end, u16bit_iterator result)
149 {
150 while (start != end) {
151 uint32_t cp = next(start);
152 if (cp > 0xffff) { //make a surrogate pair
153 *result++ = static_cast<uint16_t>((cp >> 10) + internal::LEAD_OFFSET);
154 *result++ = static_cast<uint16_t>((cp & 0x3ff) + internal::TRAIL_SURROGATE_MIN);
155 }
156 else
157 *result++ = static_cast<uint16_t>(cp);
158 }
159 return result;
160 }
161
162 template <typename octet_iterator, typename u32bit_iterator>
163 octet_iterator utf32to8 (u32bit_iterator start, u32bit_iterator end, octet_iterator result)
164 {
165 while (start != end)
166 result = append(*(start++), result);
167
168 return result;
169 }
170
171 template <typename octet_iterator, typename u32bit_iterator>
172 u32bit_iterator utf8to32 (octet_iterator start, octet_iterator end, u32bit_iterator result)
173 {
174 while (start < end)
175 (*result++) = next(start);
176
177 return result;
178 }
179
180 // The iterator class
181 template <typename octet_iterator>
182 class iterator : public std::iterator <std::bidirectional_iterator_tag, uint32_t> {
183 octet_iterator it;
184 public:
185 iterator () {};
186 explicit iterator (const octet_iterator& octet_it): it(octet_it) {}
187 // the default "big three" are OK
188 octet_iterator base () const { return it; }
189 uint32_t operator * () const
190 {
191 octet_iterator temp = it;
192 return next(temp);
193 }
194 bool operator == (const iterator& rhs) const
195 {
196 return (it == rhs.it);
197 }
198 bool operator != (const iterator& rhs) const
199 {
200 return !(operator == (rhs));
201 }
202 iterator& operator ++ ()
203 {
204 std::advance(it, internal::sequence_length(it));
205 return *this;
206 }
207 iterator operator ++ (int)
208 {
209 iterator temp = *this;
210 std::advance(it, internal::sequence_length(it));
211 return temp;
212 }
213 iterator& operator -- ()
214 {
215 prior(it);
216 return *this;
217 }
218 iterator operator -- (int)
219 {
220 iterator temp = *this;
221 prior(it);
222 return temp;
223 }
224 }; // class iterator
225
226 } // namespace utf8::unchecked
227 } // namespace utf8
228
229
230 #endif // header guard
231