Mercurial > projects > dil
annotate trunk/src/dil/Unicode.d @ 722:ceaac6a24258
Added isUnicodeAlpha() for DDocParser and MacroParser.
author | Aziz K?ksal <aziz.koeksal@gmail.com> |
---|---|
date | Fri, 01 Feb 2008 19:44:00 +0100 |
parents | d050e211402b |
children | f88b5285b86b |
rev | line source |
---|---|
510 | 1 /++ |
2 Author: Aziz Köksal | |
3 License: GPL3 | |
4 +/ | |
5 module dil.Unicode; | |
629
d050e211402b
Moved files in src/std/ to src/util/.
Aziz K?ksal <aziz.koeksal@gmail.com>
parents:
518
diff
changeset
|
6 public import util.uni : isUniAlpha; |
510 | 7 |
8 /// U+FFFD = �. Used to replace invalid Unicode characters. | |
9 const dchar REPLACEMENT_CHAR = '\uFFFD'; | |
10 /// Invalid character, returned on errors. | |
11 const dchar ERROR_CHAR = 0xD800; | |
12 | |
13 /++ | |
14 Returns true if this character is not a surrogate | |
15 code point and not higher than 0x10FFFF. | |
16 +/ | |
17 bool isValidChar(dchar d) | |
18 { | |
19 return d < 0xD800 || d > 0xDFFF && d <= 0x10FFFF; | |
20 } | |
21 | |
22 /++ | |
23 Returns true if this is one of the | |
24 There are a total of 66 noncharacters. | |
25 See_also: Chapter 16.7 Noncharacters in Unicode 5.0 | |
26 +/ | |
27 bool isNoncharacter(dchar d) | |
28 { | |
29 return 0xFDD0 <= d && d <= 0xFDEF || // 32 | |
30 d <= 0x10FFFF && (d & 0xFFFF) >= 0xFFFE; // 34 | |
31 } | |
32 | |
33 /// Returns true if this is a trail byte of a UTF-8 sequence? | |
34 bool isTrailByte(ubyte b) | |
35 { | |
36 return (b & 0xC0) == 0x80; // 10xx_xxxx | |
37 } | |
38 | |
39 /// Returns true if this is a lead byte of a UTF-8 sequence. | |
40 bool isLeadByte(ubyte b) | |
41 { | |
42 return (b & 0xC0) == 0xC0; // 11xx_xxxx | |
43 } | |
44 | |
722
ceaac6a24258
Added isUnicodeAlpha() for DDocParser and MacroParser.
Aziz K?ksal <aziz.koeksal@gmail.com>
parents:
629
diff
changeset
|
45 /// Advances ref_p only if this is a valid Unicode alpha character. |
ceaac6a24258
Added isUnicodeAlpha() for DDocParser and MacroParser.
Aziz K?ksal <aziz.koeksal@gmail.com>
parents:
629
diff
changeset
|
46 bool isUnicodeAlpha(ref char* ref_p, char* end) |
ceaac6a24258
Added isUnicodeAlpha() for DDocParser and MacroParser.
Aziz K?ksal <aziz.koeksal@gmail.com>
parents:
629
diff
changeset
|
47 in { assert(ref_p && ref_p < end); } |
ceaac6a24258
Added isUnicodeAlpha() for DDocParser and MacroParser.
Aziz K?ksal <aziz.koeksal@gmail.com>
parents:
629
diff
changeset
|
48 body |
ceaac6a24258
Added isUnicodeAlpha() for DDocParser and MacroParser.
Aziz K?ksal <aziz.koeksal@gmail.com>
parents:
629
diff
changeset
|
49 { |
ceaac6a24258
Added isUnicodeAlpha() for DDocParser and MacroParser.
Aziz K?ksal <aziz.koeksal@gmail.com>
parents:
629
diff
changeset
|
50 if (*ref_p < 0x80) |
ceaac6a24258
Added isUnicodeAlpha() for DDocParser and MacroParser.
Aziz K?ksal <aziz.koeksal@gmail.com>
parents:
629
diff
changeset
|
51 return false; |
ceaac6a24258
Added isUnicodeAlpha() for DDocParser and MacroParser.
Aziz K?ksal <aziz.koeksal@gmail.com>
parents:
629
diff
changeset
|
52 auto p = ref_p; |
ceaac6a24258
Added isUnicodeAlpha() for DDocParser and MacroParser.
Aziz K?ksal <aziz.koeksal@gmail.com>
parents:
629
diff
changeset
|
53 auto c = decode(p, end); |
ceaac6a24258
Added isUnicodeAlpha() for DDocParser and MacroParser.
Aziz K?ksal <aziz.koeksal@gmail.com>
parents:
629
diff
changeset
|
54 if (!isUniAlpha(c)) |
ceaac6a24258
Added isUnicodeAlpha() for DDocParser and MacroParser.
Aziz K?ksal <aziz.koeksal@gmail.com>
parents:
629
diff
changeset
|
55 return false; |
ceaac6a24258
Added isUnicodeAlpha() for DDocParser and MacroParser.
Aziz K?ksal <aziz.koeksal@gmail.com>
parents:
629
diff
changeset
|
56 ref_p = p; |
ceaac6a24258
Added isUnicodeAlpha() for DDocParser and MacroParser.
Aziz K?ksal <aziz.koeksal@gmail.com>
parents:
629
diff
changeset
|
57 return true; |
ceaac6a24258
Added isUnicodeAlpha() for DDocParser and MacroParser.
Aziz K?ksal <aziz.koeksal@gmail.com>
parents:
629
diff
changeset
|
58 } |
ceaac6a24258
Added isUnicodeAlpha() for DDocParser and MacroParser.
Aziz K?ksal <aziz.koeksal@gmail.com>
parents:
629
diff
changeset
|
59 |
ceaac6a24258
Added isUnicodeAlpha() for DDocParser and MacroParser.
Aziz K?ksal <aziz.koeksal@gmail.com>
parents:
629
diff
changeset
|
60 /// index is set one past the last trail byte of the valid UTF-8 sequence. |
510 | 61 dchar decode(char[] str, ref size_t index) |
722
ceaac6a24258
Added isUnicodeAlpha() for DDocParser and MacroParser.
Aziz K?ksal <aziz.koeksal@gmail.com>
parents:
629
diff
changeset
|
62 in { assert(str.length && index < str.length); } |
510 | 63 out(c) { assert(isValidChar(c)); } |
64 body | |
65 { | |
66 char* p = str.ptr + index; | |
67 char* end = str.ptr + str.length; | |
722
ceaac6a24258
Added isUnicodeAlpha() for DDocParser and MacroParser.
Aziz K?ksal <aziz.koeksal@gmail.com>
parents:
629
diff
changeset
|
68 dchar c = decode(p, end); |
ceaac6a24258
Added isUnicodeAlpha() for DDocParser and MacroParser.
Aziz K?ksal <aziz.koeksal@gmail.com>
parents:
629
diff
changeset
|
69 if (c != ERROR_CHAR) |
ceaac6a24258
Added isUnicodeAlpha() for DDocParser and MacroParser.
Aziz K?ksal <aziz.koeksal@gmail.com>
parents:
629
diff
changeset
|
70 index = p - str.ptr + 1; |
ceaac6a24258
Added isUnicodeAlpha() for DDocParser and MacroParser.
Aziz K?ksal <aziz.koeksal@gmail.com>
parents:
629
diff
changeset
|
71 return c; |
ceaac6a24258
Added isUnicodeAlpha() for DDocParser and MacroParser.
Aziz K?ksal <aziz.koeksal@gmail.com>
parents:
629
diff
changeset
|
72 } |
510 | 73 |
722
ceaac6a24258
Added isUnicodeAlpha() for DDocParser and MacroParser.
Aziz K?ksal <aziz.koeksal@gmail.com>
parents:
629
diff
changeset
|
74 /// ref_p is set to the last trail byte of the valid UTF-8 sequence. |
ceaac6a24258
Added isUnicodeAlpha() for DDocParser and MacroParser.
Aziz K?ksal <aziz.koeksal@gmail.com>
parents:
629
diff
changeset
|
75 dchar decode(ref char* ref_p, char* end) |
ceaac6a24258
Added isUnicodeAlpha() for DDocParser and MacroParser.
Aziz K?ksal <aziz.koeksal@gmail.com>
parents:
629
diff
changeset
|
76 in { assert(ref_p && ref_p < end); } |
ceaac6a24258
Added isUnicodeAlpha() for DDocParser and MacroParser.
Aziz K?ksal <aziz.koeksal@gmail.com>
parents:
629
diff
changeset
|
77 out(c) { assert(isValidChar(c)); } |
ceaac6a24258
Added isUnicodeAlpha() for DDocParser and MacroParser.
Aziz K?ksal <aziz.koeksal@gmail.com>
parents:
629
diff
changeset
|
78 body |
ceaac6a24258
Added isUnicodeAlpha() for DDocParser and MacroParser.
Aziz K?ksal <aziz.koeksal@gmail.com>
parents:
629
diff
changeset
|
79 { |
ceaac6a24258
Added isUnicodeAlpha() for DDocParser and MacroParser.
Aziz K?ksal <aziz.koeksal@gmail.com>
parents:
629
diff
changeset
|
80 char* p = ref_p; |
ceaac6a24258
Added isUnicodeAlpha() for DDocParser and MacroParser.
Aziz K?ksal <aziz.koeksal@gmail.com>
parents:
629
diff
changeset
|
81 dchar c = *p; |
510 | 82 |
83 if (c < 0x80) | |
84 { | |
722
ceaac6a24258
Added isUnicodeAlpha() for DDocParser and MacroParser.
Aziz K?ksal <aziz.koeksal@gmail.com>
parents:
629
diff
changeset
|
85 ref_p++; |
510 | 86 return c; |
87 } | |
88 | |
722
ceaac6a24258
Added isUnicodeAlpha() for DDocParser and MacroParser.
Aziz K?ksal <aziz.koeksal@gmail.com>
parents:
629
diff
changeset
|
89 p++; // Move to second byte. |
510 | 90 if (!(p < end)) |
91 return ERROR_CHAR; | |
92 | |
93 // Error if second byte is not a trail byte. | |
94 if (!isTrailByte(*p)) | |
95 return ERROR_CHAR; | |
96 | |
97 // Check for overlong sequences. | |
98 switch (c) | |
99 { | |
100 case 0xE0, // 11100000 100xxxxx | |
101 0xF0, // 11110000 1000xxxx | |
102 0xF8, // 11111000 10000xxx | |
103 0xFC: // 11111100 100000xx | |
104 if ((*p & c) == 0x80) | |
105 return ERROR_CHAR; | |
106 default: | |
107 if ((c & 0xFE) == 0xC0) // 1100000x | |
108 return ERROR_CHAR; | |
109 } | |
110 | |
722
ceaac6a24258
Added isUnicodeAlpha() for DDocParser and MacroParser.
Aziz K?ksal <aziz.koeksal@gmail.com>
parents:
629
diff
changeset
|
111 const char[] checkNextByte = "if (!(++p < end && isTrailByte(*p)))" |
510 | 112 " return ERROR_CHAR;"; |
113 const char[] appendSixBits = "c = (c << 6) | *p & 0b0011_1111;"; | |
114 | |
115 // Decode | |
116 if ((c & 0b1110_0000) == 0b1100_0000) | |
117 { | |
118 // 110xxxxx 10xxxxxx | |
119 c &= 0b0001_1111; | |
120 mixin(appendSixBits); | |
121 } | |
122 else if ((c & 0b1111_0000) == 0b1110_0000) | |
123 { | |
124 // 1110xxxx 10xxxxxx 10xxxxxx | |
125 c &= 0b0000_1111; | |
126 mixin(appendSixBits ~ | |
127 checkNextByte ~ appendSixBits); | |
128 } | |
129 else if ((c & 0b1111_1000) == 0b1111_0000) | |
130 { | |
131 // 11110xxx 10xxxxxx 10xxxxxx 10xxxxxx | |
132 c &= 0b0000_0111; | |
133 mixin(appendSixBits ~ | |
134 checkNextByte ~ appendSixBits ~ | |
135 checkNextByte ~ appendSixBits); | |
136 } | |
137 else | |
138 // 5 and 6 byte UTF-8 sequences are not allowed yet. | |
139 // 111110xx 10xxxxxx 10xxxxxx 10xxxxxx 10xxxxxx | |
140 // 1111110x 10xxxxxx 10xxxxxx 10xxxxxx 10xxxxxx 10xxxxxx | |
141 return ERROR_CHAR; | |
142 | |
143 assert(isTrailByte(*p)); | |
144 | |
145 if (!isValidChar(c)) | |
146 return ERROR_CHAR; | |
722
ceaac6a24258
Added isUnicodeAlpha() for DDocParser and MacroParser.
Aziz K?ksal <aziz.koeksal@gmail.com>
parents:
629
diff
changeset
|
147 ref_p = p; |
510 | 148 return c; |
149 } | |
150 | |
151 /// Encodes a character and appends it to str. | |
518
8f86bb9ef715
Added module dil.Converter and dil.FileBOM.
Aziz K?ksal <aziz.koeksal@gmail.com>
parents:
510
diff
changeset
|
152 void encode(ref char[] str, dchar c) |
8f86bb9ef715
Added module dil.Converter and dil.FileBOM.
Aziz K?ksal <aziz.koeksal@gmail.com>
parents:
510
diff
changeset
|
153 { |
8f86bb9ef715
Added module dil.Converter and dil.FileBOM.
Aziz K?ksal <aziz.koeksal@gmail.com>
parents:
510
diff
changeset
|
154 assert(isValidChar(c), "check if character is valid before calling encode()."); |
8f86bb9ef715
Added module dil.Converter and dil.FileBOM.
Aziz K?ksal <aziz.koeksal@gmail.com>
parents:
510
diff
changeset
|
155 |
8f86bb9ef715
Added module dil.Converter and dil.FileBOM.
Aziz K?ksal <aziz.koeksal@gmail.com>
parents:
510
diff
changeset
|
156 char[6] b = void; |
8f86bb9ef715
Added module dil.Converter and dil.FileBOM.
Aziz K?ksal <aziz.koeksal@gmail.com>
parents:
510
diff
changeset
|
157 if (c < 0x80) |
8f86bb9ef715
Added module dil.Converter and dil.FileBOM.
Aziz K?ksal <aziz.koeksal@gmail.com>
parents:
510
diff
changeset
|
158 str ~= c; |
8f86bb9ef715
Added module dil.Converter and dil.FileBOM.
Aziz K?ksal <aziz.koeksal@gmail.com>
parents:
510
diff
changeset
|
159 if (c < 0x800) |
8f86bb9ef715
Added module dil.Converter and dil.FileBOM.
Aziz K?ksal <aziz.koeksal@gmail.com>
parents:
510
diff
changeset
|
160 { |
8f86bb9ef715
Added module dil.Converter and dil.FileBOM.
Aziz K?ksal <aziz.koeksal@gmail.com>
parents:
510
diff
changeset
|
161 b[0] = 0xC0 | (c >> 6); |
8f86bb9ef715
Added module dil.Converter and dil.FileBOM.
Aziz K?ksal <aziz.koeksal@gmail.com>
parents:
510
diff
changeset
|
162 b[1] = 0x80 | (c & 0x3F); |
8f86bb9ef715
Added module dil.Converter and dil.FileBOM.
Aziz K?ksal <aziz.koeksal@gmail.com>
parents:
510
diff
changeset
|
163 str ~= b[0..2]; |
8f86bb9ef715
Added module dil.Converter and dil.FileBOM.
Aziz K?ksal <aziz.koeksal@gmail.com>
parents:
510
diff
changeset
|
164 } |
8f86bb9ef715
Added module dil.Converter and dil.FileBOM.
Aziz K?ksal <aziz.koeksal@gmail.com>
parents:
510
diff
changeset
|
165 else if (c < 0x10000) |
8f86bb9ef715
Added module dil.Converter and dil.FileBOM.
Aziz K?ksal <aziz.koeksal@gmail.com>
parents:
510
diff
changeset
|
166 { |
8f86bb9ef715
Added module dil.Converter and dil.FileBOM.
Aziz K?ksal <aziz.koeksal@gmail.com>
parents:
510
diff
changeset
|
167 b[0] = 0xE0 | (c >> 12); |
8f86bb9ef715
Added module dil.Converter and dil.FileBOM.
Aziz K?ksal <aziz.koeksal@gmail.com>
parents:
510
diff
changeset
|
168 b[1] = 0x80 | ((c >> 6) & 0x3F); |
8f86bb9ef715
Added module dil.Converter and dil.FileBOM.
Aziz K?ksal <aziz.koeksal@gmail.com>
parents:
510
diff
changeset
|
169 b[2] = 0x80 | (c & 0x3F); |
8f86bb9ef715
Added module dil.Converter and dil.FileBOM.
Aziz K?ksal <aziz.koeksal@gmail.com>
parents:
510
diff
changeset
|
170 str ~= b[0..3]; |
8f86bb9ef715
Added module dil.Converter and dil.FileBOM.
Aziz K?ksal <aziz.koeksal@gmail.com>
parents:
510
diff
changeset
|
171 } |
8f86bb9ef715
Added module dil.Converter and dil.FileBOM.
Aziz K?ksal <aziz.koeksal@gmail.com>
parents:
510
diff
changeset
|
172 else if (c < 0x200000) |
8f86bb9ef715
Added module dil.Converter and dil.FileBOM.
Aziz K?ksal <aziz.koeksal@gmail.com>
parents:
510
diff
changeset
|
173 { |
8f86bb9ef715
Added module dil.Converter and dil.FileBOM.
Aziz K?ksal <aziz.koeksal@gmail.com>
parents:
510
diff
changeset
|
174 b[0] = 0xF0 | (c >> 18); |
8f86bb9ef715
Added module dil.Converter and dil.FileBOM.
Aziz K?ksal <aziz.koeksal@gmail.com>
parents:
510
diff
changeset
|
175 b[1] = 0x80 | ((c >> 12) & 0x3F); |
8f86bb9ef715
Added module dil.Converter and dil.FileBOM.
Aziz K?ksal <aziz.koeksal@gmail.com>
parents:
510
diff
changeset
|
176 b[2] = 0x80 | ((c >> 6) & 0x3F); |
8f86bb9ef715
Added module dil.Converter and dil.FileBOM.
Aziz K?ksal <aziz.koeksal@gmail.com>
parents:
510
diff
changeset
|
177 b[3] = 0x80 | (c & 0x3F); |
8f86bb9ef715
Added module dil.Converter and dil.FileBOM.
Aziz K?ksal <aziz.koeksal@gmail.com>
parents:
510
diff
changeset
|
178 str ~= b[0..4]; |
8f86bb9ef715
Added module dil.Converter and dil.FileBOM.
Aziz K?ksal <aziz.koeksal@gmail.com>
parents:
510
diff
changeset
|
179 } |
8f86bb9ef715
Added module dil.Converter and dil.FileBOM.
Aziz K?ksal <aziz.koeksal@gmail.com>
parents:
510
diff
changeset
|
180 /+ // There are no 5 and 6 byte UTF-8 sequences yet. |
8f86bb9ef715
Added module dil.Converter and dil.FileBOM.
Aziz K?ksal <aziz.koeksal@gmail.com>
parents:
510
diff
changeset
|
181 else if (c < 0x4000000) |
8f86bb9ef715
Added module dil.Converter and dil.FileBOM.
Aziz K?ksal <aziz.koeksal@gmail.com>
parents:
510
diff
changeset
|
182 { |
8f86bb9ef715
Added module dil.Converter and dil.FileBOM.
Aziz K?ksal <aziz.koeksal@gmail.com>
parents:
510
diff
changeset
|
183 b[0] = 0xF8 | (c >> 24); |
8f86bb9ef715
Added module dil.Converter and dil.FileBOM.
Aziz K?ksal <aziz.koeksal@gmail.com>
parents:
510
diff
changeset
|
184 b[1] = 0x80 | ((c >> 18) & 0x3F); |
8f86bb9ef715
Added module dil.Converter and dil.FileBOM.
Aziz K?ksal <aziz.koeksal@gmail.com>
parents:
510
diff
changeset
|
185 b[2] = 0x80 | ((c >> 12) & 0x3F); |
8f86bb9ef715
Added module dil.Converter and dil.FileBOM.
Aziz K?ksal <aziz.koeksal@gmail.com>
parents:
510
diff
changeset
|
186 b[3] = 0x80 | ((c >> 6) & 0x3F); |
8f86bb9ef715
Added module dil.Converter and dil.FileBOM.
Aziz K?ksal <aziz.koeksal@gmail.com>
parents:
510
diff
changeset
|
187 b[4] = 0x80 | (c & 0x3F); |
8f86bb9ef715
Added module dil.Converter and dil.FileBOM.
Aziz K?ksal <aziz.koeksal@gmail.com>
parents:
510
diff
changeset
|
188 str ~= b[0..5]; |
8f86bb9ef715
Added module dil.Converter and dil.FileBOM.
Aziz K?ksal <aziz.koeksal@gmail.com>
parents:
510
diff
changeset
|
189 } |
8f86bb9ef715
Added module dil.Converter and dil.FileBOM.
Aziz K?ksal <aziz.koeksal@gmail.com>
parents:
510
diff
changeset
|
190 else if (c < 0x80000000) |
8f86bb9ef715
Added module dil.Converter and dil.FileBOM.
Aziz K?ksal <aziz.koeksal@gmail.com>
parents:
510
diff
changeset
|
191 { |
8f86bb9ef715
Added module dil.Converter and dil.FileBOM.
Aziz K?ksal <aziz.koeksal@gmail.com>
parents:
510
diff
changeset
|
192 b[0] = 0xFC | (c >> 30); |
8f86bb9ef715
Added module dil.Converter and dil.FileBOM.
Aziz K?ksal <aziz.koeksal@gmail.com>
parents:
510
diff
changeset
|
193 b[1] = 0x80 | ((c >> 24) & 0x3F); |
8f86bb9ef715
Added module dil.Converter and dil.FileBOM.
Aziz K?ksal <aziz.koeksal@gmail.com>
parents:
510
diff
changeset
|
194 b[2] = 0x80 | ((c >> 18) & 0x3F); |
8f86bb9ef715
Added module dil.Converter and dil.FileBOM.
Aziz K?ksal <aziz.koeksal@gmail.com>
parents:
510
diff
changeset
|
195 b[3] = 0x80 | ((c >> 12) & 0x3F); |
8f86bb9ef715
Added module dil.Converter and dil.FileBOM.
Aziz K?ksal <aziz.koeksal@gmail.com>
parents:
510
diff
changeset
|
196 b[4] = 0x80 | ((c >> 6) & 0x3F); |
8f86bb9ef715
Added module dil.Converter and dil.FileBOM.
Aziz K?ksal <aziz.koeksal@gmail.com>
parents:
510
diff
changeset
|
197 b[5] = 0x80 | (c & 0x3F); |
8f86bb9ef715
Added module dil.Converter and dil.FileBOM.
Aziz K?ksal <aziz.koeksal@gmail.com>
parents:
510
diff
changeset
|
198 str ~= b[0..6]; |
8f86bb9ef715
Added module dil.Converter and dil.FileBOM.
Aziz K?ksal <aziz.koeksal@gmail.com>
parents:
510
diff
changeset
|
199 } |
8f86bb9ef715
Added module dil.Converter and dil.FileBOM.
Aziz K?ksal <aziz.koeksal@gmail.com>
parents:
510
diff
changeset
|
200 +/ |
8f86bb9ef715
Added module dil.Converter and dil.FileBOM.
Aziz K?ksal <aziz.koeksal@gmail.com>
parents:
510
diff
changeset
|
201 else |
8f86bb9ef715
Added module dil.Converter and dil.FileBOM.
Aziz K?ksal <aziz.koeksal@gmail.com>
parents:
510
diff
changeset
|
202 assert(0); |
8f86bb9ef715
Added module dil.Converter and dil.FileBOM.
Aziz K?ksal <aziz.koeksal@gmail.com>
parents:
510
diff
changeset
|
203 } |
8f86bb9ef715
Added module dil.Converter and dil.FileBOM.
Aziz K?ksal <aziz.koeksal@gmail.com>
parents:
510
diff
changeset
|
204 |
8f86bb9ef715
Added module dil.Converter and dil.FileBOM.
Aziz K?ksal <aziz.koeksal@gmail.com>
parents:
510
diff
changeset
|
205 /// Encodes a character and appends it to str. |
510 | 206 void encode(ref wchar[] str, dchar c) |
207 in { assert(isValidChar(c)); } | |
208 body | |
209 { | |
210 if (c < 0x10000) | |
211 str ~= cast(wchar)c; | |
212 else | |
213 { | |
214 // Encode with surrogate pair. | |
215 wchar[2] pair = void; | |
216 c -= 0x10000; // c' | |
217 // higher10bits(c') | 0b1101_10xx_xxxx_xxxx | |
218 pair[0] = (c >> 10) | 0xD800; | |
219 // lower10bits(c') | 0b1101_11yy_yyyy_yyyy | |
220 pair[1] = (c & 0x3FF) | 0xDC00; | |
221 str ~= pair; | |
222 } | |
223 } | |
224 | |
225 /++ | |
226 Returns a decoded character from a UTF-16 sequence. | |
227 In case of an error in the sequence 0xD800 is returned. | |
228 Params: | |
229 str = the UTF-16 sequence. | |
230 index = where to start from. | |
231 +/ | |
232 dchar decode(wchar[] str, ref size_t index) | |
233 { | |
234 assert(str.length && index < str.length); | |
235 dchar c = str[index]; | |
236 if (0xD800 > c || c > 0xDFFF) | |
237 { | |
238 ++index; | |
239 return c; | |
240 } | |
241 if (c <= 0xDBFF && index+1 != str.length) | |
242 { | |
243 wchar c2 = str[index+1]; | |
244 if (0xDC00 <= c2 && c2 <= 0xDFFF) | |
245 { | |
246 // (c - 0xD800) << 10 + 0x10000 -> | |
247 // (c - 0xD800 + 0x40) << 10 -> | |
248 c = (c - 0xD7C0) << 10; | |
249 c |= (c2 & 0x3FF); | |
250 index += 2; | |
251 return c; | |
252 } | |
253 } | |
254 return ERROR_CHAR; | |
255 } | |
256 | |
257 /++ | |
258 Returns a decoded character from a UTF-16 sequence. | |
259 In case of an error in the sequence 0xD800 is returned. | |
260 Params: | |
261 p = start of the UTF-16 sequence. | |
262 end = one past the end of the sequence. | |
263 +/ | |
264 dchar decode(ref wchar* p, wchar* end) | |
265 { | |
266 assert(p && p < end); | |
267 dchar c = *p; | |
268 if (0xD800 > c || c > 0xDFFF) | |
269 { | |
270 ++p; | |
271 return c; | |
272 } | |
273 if (c <= 0xDBFF && p+1 != end) | |
274 { | |
275 wchar c2 = p[1]; | |
276 if (0xDC00 <= c2 && c2 <= 0xDFFF) | |
277 { | |
278 c = (c - 0xD7C0) << 10; | |
279 c |= (c2 & 0x3FF); | |
280 p += 2; | |
281 return c; | |
282 } | |
283 } | |
284 return ERROR_CHAR; | |
285 } | |
286 | |
287 /// Decode a character from a zero-terminated string. | |
288 dchar decode(ref wchar* p) | |
289 { | |
290 assert(p); | |
291 dchar c = *p; | |
292 if (0xD800 > c || c > 0xDFFF) | |
293 { | |
294 ++p; | |
295 return c; | |
296 } | |
297 if (c <= 0xDBFF) | |
298 { | |
299 wchar c2 = p[1]; | |
300 if (0xDC00 <= c2 && c2 <= 0xDFFF) | |
301 { | |
302 c = (c - 0xD7C0) << 10; | |
303 c |= (c2 & 0x3FF); | |
304 p += 2; | |
305 return c; | |
306 } | |
307 } | |
308 return ERROR_CHAR; | |
309 } |