1 /*
2 * This is an implementation of wcwidth() and wcswidth() (defined in
3 * IEEE Std 1002.1-2001) for Unicode.
4 *
5 * http://www.opengroup.org/onlinepubs/007904975/functions/wcwidth.html
6 * http://www.opengroup.org/onlinepubs/007904975/functions/wcswidth.html
7 *
8 * In fixed-width output devices, Latin characters all occupy a single
9 * "cell" position of equal width, whereas ideographic CJK characters
10 * occupy two such cells. Interoperability between terminal-line
11 * applications and (teletype-style) character terminals using the
12 * UTF-8 encoding requires agreement on which character should advance
13 * the cursor by how many cell positions. No established formal
14 * standards exist at present on which Unicode character shall occupy
15 * how many cell positions on character terminals. These routines are
16 * a first attempt of defining such behavior based on simple rules
17 * applied to data provided by the Unicode Consortium.
18 *
19 * For some graphical characters, the Unicode standard explicitly
20 * defines a character-cell width via the definition of the East Asian
21 * FullWidth (F), Wide (W), Half-width (H), and Narrow (Na) classes.
22 * In all these cases, there is no ambiguity about which width a
23 * terminal shall use. For characters in the East Asian Ambiguous (A)
24 * class, the width choice depends purely on a preference of backward
25 * compatibility with either historic CJK or Western practice.
26 * Choosing single-width for these characters is easy to justify as
27 * the appropriate long-term solution, as the CJK practice of
28 * displaying these characters as double-width comes from historic
29 * implementation simplicity (8-bit encoded characters were displayed
30 * single-width and 16-bit ones double-width, even for Greek,
31 * Cyrillic, etc.) and not any typographic considerations.
32 *
33 * Much less clear is the choice of width for the Not East Asian
34 * (Neutral) class. Existing practice does not dictate a width for any
35 * of these characters. It would nevertheless make sense
36 * typographically to allocate two character cells to characters such
37 * as for instance EM SPACE or VOLUME INTEGRAL, which cannot be
38 * represented adequately with a single-width glyph. The following
39 * routines at present merely assign a single-cell width to all
40 * neutral characters, in the interest of simplicity. This is not
41 * entirely satisfactory and should be reconsidered before
42 * establishing a formal standard in this area. At the moment, the
43 * decision which Not East Asian (Neutral) characters should be
44 * represented by double-width glyphs cannot yet be answered by
45 * applying a simple rule from the Unicode database content. Setting
46 * up a proper standard for the behavior of UTF-8 character terminals
47 * will require a careful analysis not only of each Unicode character,
48 * but also of each presentation form, something the author of these
49 * routines has avoided to do so far.
50 *
51 * http://www.unicode.org/unicode/reports/tr11/
52 *
53 * Markus Kuhn -- 2002-05-08 (Unicode 3.2)
54 *
55 * Permission to use, copy, modify, and distribute this software
56 * for any purpose and without fee is hereby granted. The author
57 * disclaims all warranties with regard to this software.
58 *
59 * Latest version: http://www.cl.cam.ac.uk/~mgk25/ucs/wcwidth.c
60 */
61
62 #include <wchar.h>
63
64 struct interval {
65 int first;
66 int last;
67 };
68
69 /* auxiliary function for binary search in interval table */
bisearch(wchar_t ucs,const struct interval * table,int max)70 static int bisearch(wchar_t ucs, const struct interval *table, int max) {
71 int min = 0;
72 int mid;
73
74 if (ucs < table[0].first || ucs > table[max].last)
75 return 0;
76 while (max >= min) {
77 mid = (min + max) / 2;
78 if (ucs > table[mid].last)
79 min = mid + 1;
80 else if (ucs < table[mid].first)
81 max = mid - 1;
82 else
83 return 1;
84 }
85
86 return 0;
87 }
88
89
90 /* The following two functions define the column width of an ISO 10646
91 * character as follows:
92 *
93 * - The null character (U+0000) has a column width of 0.
94 *
95 * - Other C0/C1 control characters and DEL will lead to a return
96 * value of -1.
97 *
98 * - Non-spacing and enclosing combining characters (general
99 * category code Mn or Me in the Unicode database) have a
100 * column width of 0.
101 *
102 * - Other format characters (general category code Cf in the Unicode
103 * database) and ZERO WIDTH SPACE (U+200B) have a column width of 0.
104 *
105 * - Hangul Jamo medial vowels and final consonants (U+1160-U+11FF)
106 * have a column width of 0.
107 *
108 * - Spacing characters in the East Asian Wide (W) or East Asian
109 * Full-width (F) category as defined in Unicode Technical
110 * Report #11 have a column width of 2.
111 *
112 * - All remaining characters (including all printable
113 * ISO 8859-1 and WGL4 characters, Unicode control characters,
114 * etc.) have a column width of 1.
115 *
116 * This implementation assumes that wchar_t characters are encoded
117 * in ISO 10646.
118 */
119
mk_wcwidth(wchar_t ucs)120 int mk_wcwidth(wchar_t ucs)
121 {
122 /* sorted list of non-overlapping intervals of non-spacing characters */
123 /* generated with "uniset +cat=Me +cat=Mn +cat=Cf +1160-11FF +200B c" */
124 static const struct interval combining[] = {
125 { 0x0300, 0x034F }, { 0x0360, 0x036F }, { 0x0483, 0x0486 },
126 { 0x0488, 0x0489 }, { 0x0591, 0x05A1 }, { 0x05A3, 0x05B9 },
127 { 0x05BB, 0x05BD }, { 0x05BF, 0x05BF }, { 0x05C1, 0x05C2 },
128 { 0x05C4, 0x05C4 }, { 0x064B, 0x0655 }, { 0x0670, 0x0670 },
129 { 0x06D6, 0x06E4 }, { 0x06E7, 0x06E8 }, { 0x06EA, 0x06ED },
130 { 0x070F, 0x070F }, { 0x0711, 0x0711 }, { 0x0730, 0x074A },
131 { 0x07A6, 0x07B0 }, { 0x0901, 0x0902 }, { 0x093C, 0x093C },
132 { 0x0941, 0x0948 }, { 0x094D, 0x094D }, { 0x0951, 0x0954 },
133 { 0x0962, 0x0963 }, { 0x0981, 0x0981 }, { 0x09BC, 0x09BC },
134 { 0x09C1, 0x09C4 }, { 0x09CD, 0x09CD }, { 0x09E2, 0x09E3 },
135 { 0x0A02, 0x0A02 }, { 0x0A3C, 0x0A3C }, { 0x0A41, 0x0A42 },
136 { 0x0A47, 0x0A48 }, { 0x0A4B, 0x0A4D }, { 0x0A70, 0x0A71 },
137 { 0x0A81, 0x0A82 }, { 0x0ABC, 0x0ABC }, { 0x0AC1, 0x0AC5 },
138 { 0x0AC7, 0x0AC8 }, { 0x0ACD, 0x0ACD }, { 0x0B01, 0x0B01 },
139 { 0x0B3C, 0x0B3C }, { 0x0B3F, 0x0B3F }, { 0x0B41, 0x0B43 },
140 { 0x0B4D, 0x0B4D }, { 0x0B56, 0x0B56 }, { 0x0B82, 0x0B82 },
141 { 0x0BC0, 0x0BC0 }, { 0x0BCD, 0x0BCD }, { 0x0C3E, 0x0C40 },
142 { 0x0C46, 0x0C48 }, { 0x0C4A, 0x0C4D }, { 0x0C55, 0x0C56 },
143 { 0x0CBF, 0x0CBF }, { 0x0CC6, 0x0CC6 }, { 0x0CCC, 0x0CCD },
144 { 0x0D41, 0x0D43 }, { 0x0D4D, 0x0D4D }, { 0x0DCA, 0x0DCA },
145 { 0x0DD2, 0x0DD4 }, { 0x0DD6, 0x0DD6 }, { 0x0E31, 0x0E31 },
146 { 0x0E34, 0x0E3A }, { 0x0E47, 0x0E4E }, { 0x0EB1, 0x0EB1 },
147 { 0x0EB4, 0x0EB9 }, { 0x0EBB, 0x0EBC }, { 0x0EC8, 0x0ECD },
148 { 0x0F18, 0x0F19 }, { 0x0F35, 0x0F35 }, { 0x0F37, 0x0F37 },
149 { 0x0F39, 0x0F39 }, { 0x0F71, 0x0F7E }, { 0x0F80, 0x0F84 },
150 { 0x0F86, 0x0F87 }, { 0x0F90, 0x0F97 }, { 0x0F99, 0x0FBC },
151 { 0x0FC6, 0x0FC6 }, { 0x102D, 0x1030 }, { 0x1032, 0x1032 },
152 { 0x1036, 0x1037 }, { 0x1039, 0x1039 }, { 0x1058, 0x1059 },
153 { 0x1160, 0x11FF }, { 0x1712, 0x1714 }, { 0x1732, 0x1734 },
154 { 0x1752, 0x1753 }, { 0x1772, 0x1773 }, { 0x17B7, 0x17BD },
155 { 0x17C6, 0x17C6 }, { 0x17C9, 0x17D3 }, { 0x180B, 0x180E },
156 { 0x18A9, 0x18A9 }, { 0x200B, 0x200F }, { 0x202A, 0x202E },
157 { 0x2060, 0x2063 }, { 0x206A, 0x206F }, { 0x20D0, 0x20EA },
158 { 0x302A, 0x302F }, { 0x3099, 0x309A }, { 0xFB1E, 0xFB1E },
159 { 0xFE00, 0xFE0F }, { 0xFE20, 0xFE23 }, { 0xFEFF, 0xFEFF },
160 { 0xFFF9, 0xFFFB }, { 0x1D167, 0x1D169 }, { 0x1D173, 0x1D182 },
161 { 0x1D185, 0x1D18B }, { 0x1D1AA, 0x1D1AD }, { 0xE0001, 0xE0001 },
162 { 0xE0020, 0xE007F }
163 };
164
165 /* test for 8-bit control characters */
166 if (ucs == 0)
167 return 0;
168 if (ucs < 32 || (ucs >= 0x7f && ucs < 0xa0))
169 return -1;
170
171 /* binary search in table of non-spacing characters */
172 if (bisearch(ucs, combining,
173 sizeof(combining) / sizeof(struct interval) - 1))
174 return 0;
175
176 /* if we arrive here, ucs is not a combining or C0/C1 control character */
177
178 return 1 +
179 (ucs >= 0x1100 &&
180 (ucs <= 0x115f || /* Hangul Jamo init. consonants */
181 ucs == 0x2329 || ucs == 0x232a ||
182 (ucs >= 0x2e80 && ucs <= 0xa4cf &&
183 ucs != 0x303f) || /* CJK ... Yi */
184 (ucs >= 0xac00 && ucs <= 0xd7a3) || /* Hangul Syllables */
185 (ucs >= 0xf900 && ucs <= 0xfaff) || /* CJK Compatibility Ideographs */
186 (ucs >= 0xfe30 && ucs <= 0xfe6f) || /* CJK Compatibility Forms */
187 (ucs >= 0xff00 && ucs <= 0xff60) || /* Fullwidth Forms */
188 (ucs >= 0xffe0 && ucs <= 0xffe6) ||
189 (ucs >= 0x20000 && ucs <= 0x2ffff)));
190 }
191
192
mk_wcswidth(const wchar_t * pwcs,size_t n)193 int mk_wcswidth(const wchar_t *pwcs, size_t n)
194 {
195 int w, width = 0;
196
197 for (;*pwcs && n-- > 0; pwcs++)
198 if ((w = mk_wcwidth(*pwcs)) < 0)
199 return -1;
200 else
201 width += w;
202
203 return width;
204 }
205
206
207 /*
208 * The following functions are the same as mk_wcwidth() and
209 * mk_wcwidth_cjk(), except that spacing characters in the East Asian
210 * Ambiguous (A) category as defined in Unicode Technical Report #11
211 * have a column width of 2. This variant might be useful for users of
212 * CJK legacy encodings who want to migrate to UCS without changing
213 * the traditional terminal character-width behaviour. It is not
214 * otherwise recommended for general use.
215 */
mk_wcwidth_cjk(wchar_t ucs)216 static int mk_wcwidth_cjk(wchar_t ucs)
217 {
218 /* sorted list of non-overlapping intervals of East Asian Ambiguous
219 * characters, generated with "uniset +WIDTH-A -cat=Me -cat=Mn -cat=Cf c" */
220 static const struct interval ambiguous[] = {
221 { 0x00A1, 0x00A1 }, { 0x00A4, 0x00A4 }, { 0x00A7, 0x00A8 },
222 { 0x00AA, 0x00AA }, { 0x00AD, 0x00AE }, { 0x00B0, 0x00B4 },
223 { 0x00B6, 0x00BA }, { 0x00BC, 0x00BF }, { 0x00C6, 0x00C6 },
224 { 0x00D0, 0x00D0 }, { 0x00D7, 0x00D8 }, { 0x00DE, 0x00E1 },
225 { 0x00E6, 0x00E6 }, { 0x00E8, 0x00EA }, { 0x00EC, 0x00ED },
226 { 0x00F0, 0x00F0 }, { 0x00F2, 0x00F3 }, { 0x00F7, 0x00FA },
227 { 0x00FC, 0x00FC }, { 0x00FE, 0x00FE }, { 0x0101, 0x0101 },
228 { 0x0111, 0x0111 }, { 0x0113, 0x0113 }, { 0x011B, 0x011B },
229 { 0x0126, 0x0127 }, { 0x012B, 0x012B }, { 0x0131, 0x0133 },
230 { 0x0138, 0x0138 }, { 0x013F, 0x0142 }, { 0x0144, 0x0144 },
231 { 0x0148, 0x014B }, { 0x014D, 0x014D }, { 0x0152, 0x0153 },
232 { 0x0166, 0x0167 }, { 0x016B, 0x016B }, { 0x01CE, 0x01CE },
233 { 0x01D0, 0x01D0 }, { 0x01D2, 0x01D2 }, { 0x01D4, 0x01D4 },
234 { 0x01D6, 0x01D6 }, { 0x01D8, 0x01D8 }, { 0x01DA, 0x01DA },
235 { 0x01DC, 0x01DC }, { 0x0251, 0x0251 }, { 0x0261, 0x0261 },
236 { 0x02C4, 0x02C4 }, { 0x02C7, 0x02C7 }, { 0x02C9, 0x02CB },
237 { 0x02CD, 0x02CD }, { 0x02D0, 0x02D0 }, { 0x02D8, 0x02DB },
238 { 0x02DD, 0x02DD }, { 0x02DF, 0x02DF }, { 0x0391, 0x03A1 },
239 { 0x03A3, 0x03A9 }, { 0x03B1, 0x03C1 }, { 0x03C3, 0x03C9 },
240 { 0x0401, 0x0401 }, { 0x0410, 0x044F }, { 0x0451, 0x0451 },
241 { 0x2010, 0x2010 }, { 0x2013, 0x2016 }, { 0x2018, 0x2019 },
242 { 0x201C, 0x201D }, { 0x2020, 0x2022 }, { 0x2024, 0x2027 },
243 { 0x2030, 0x2030 }, { 0x2032, 0x2033 }, { 0x2035, 0x2035 },
244 { 0x203B, 0x203B }, { 0x203E, 0x203E }, { 0x2074, 0x2074 },
245 { 0x207F, 0x207F }, { 0x2081, 0x2084 }, { 0x20AC, 0x20AC },
246 { 0x2103, 0x2103 }, { 0x2105, 0x2105 }, { 0x2109, 0x2109 },
247 { 0x2113, 0x2113 }, { 0x2116, 0x2116 }, { 0x2121, 0x2122 },
248 { 0x2126, 0x2126 }, { 0x212B, 0x212B }, { 0x2153, 0x2154 },
249 { 0x215B, 0x215E }, { 0x2160, 0x216B }, { 0x2170, 0x2179 },
250 { 0x2190, 0x2199 }, { 0x21B8, 0x21B9 }, { 0x21D2, 0x21D2 },
251 { 0x21D4, 0x21D4 }, { 0x21E7, 0x21E7 }, { 0x2200, 0x2200 },
252 { 0x2202, 0x2203 }, { 0x2207, 0x2208 }, { 0x220B, 0x220B },
253 { 0x220F, 0x220F }, { 0x2211, 0x2211 }, { 0x2215, 0x2215 },
254 { 0x221A, 0x221A }, { 0x221D, 0x2220 }, { 0x2223, 0x2223 },
255 { 0x2225, 0x2225 }, { 0x2227, 0x222C }, { 0x222E, 0x222E },
256 { 0x2234, 0x2237 }, { 0x223C, 0x223D }, { 0x2248, 0x2248 },
257 { 0x224C, 0x224C }, { 0x2252, 0x2252 }, { 0x2260, 0x2261 },
258 { 0x2264, 0x2267 }, { 0x226A, 0x226B }, { 0x226E, 0x226F },
259 { 0x2282, 0x2283 }, { 0x2286, 0x2287 }, { 0x2295, 0x2295 },
260 { 0x2299, 0x2299 }, { 0x22A5, 0x22A5 }, { 0x22BF, 0x22BF },
261 { 0x2312, 0x2312 }, { 0x2460, 0x24E9 }, { 0x24EB, 0x24FE },
262 { 0x2500, 0x254B }, { 0x2550, 0x2573 }, { 0x2580, 0x258F },
263 { 0x2592, 0x2595 }, { 0x25A0, 0x25A1 }, { 0x25A3, 0x25A9 },
264 { 0x25B2, 0x25B3 }, { 0x25B6, 0x25B7 }, { 0x25BC, 0x25BD },
265 { 0x25C0, 0x25C1 }, { 0x25C6, 0x25C8 }, { 0x25CB, 0x25CB },
266 { 0x25CE, 0x25D1 }, { 0x25E2, 0x25E5 }, { 0x25EF, 0x25EF },
267 { 0x2605, 0x2606 }, { 0x2609, 0x2609 }, { 0x260E, 0x260F },
268 { 0x261C, 0x261C }, { 0x261E, 0x261E }, { 0x2640, 0x2640 },
269 { 0x2642, 0x2642 }, { 0x2660, 0x2661 }, { 0x2663, 0x2665 },
270 { 0x2667, 0x266A }, { 0x266C, 0x266D }, { 0x266F, 0x266F },
271 { 0x273D, 0x273D }, { 0x2776, 0x277F }, { 0xFFFD, 0xFFFD }
272 };
273
274 /* binary search in table of non-spacing characters */
275 if (bisearch(ucs, ambiguous,
276 sizeof(ambiguous) / sizeof(struct interval) - 1))
277 return 2;
278
279 return mk_wcwidth(ucs);
280 }
281
282
mk_wcswidth_cjk(const wchar_t * pwcs,size_t n)283 int mk_wcswidth_cjk(const wchar_t *pwcs, size_t n)
284 {
285 int w, width = 0;
286
287 for (;*pwcs && n-- > 0; pwcs++)
288 if ((w = mk_wcwidth_cjk(*pwcs)) < 0)
289 return -1;
290 else
291 width += w;
292
293 return width;
294 }
295