2 * This is an implementation of wcwidth() and wcswidth() (defined in
3 * IEEE Std 1002.1-2001) for Unicode.
5 * http://www.opengroup.org/onlinepubs/007904975/functions/wcwidth.html
6 * http://www.opengroup.org/onlinepubs/007904975/functions/wcswidth.html
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.
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.
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.
51 * http://www.unicode.org/unicode/reports/tr11/
53 * Markus Kuhn -- 2003-05-20 (Unicode 4.0)
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.
59 * Latest version: http://www.cl.cam.ac.uk/~mgk25/ucs/wcwidth.c
80 /* auxiliary function for binary search in interval table */
81 static int bisearch(wchar_t ucs, const struct interval *table, int max) {
85 if (ucs < table[0].first || ucs > table[max].last)
88 mid = (min + max) / 2;
89 if (ucs > table[mid].last)
91 else if (ucs < table[mid].first)
101 /* The following two functions define the column width of an ISO 10646
102 * character as follows:
104 * - The null character (U+0000) has a column width of 0.
106 * - Other C0/C1 control characters and DEL will lead to a return
109 * - Non-spacing and enclosing combining characters (general
110 * category code Mn or Me in the Unicode database) have a
113 * - SOFT HYPHEN (U+00AD) has a column width of 1.
115 * - Other format characters (general category code Cf in the Unicode
116 * database) and ZERO WIDTH SPACE (U+200B) have a column width of 0.
118 * - Hangul Jamo medial vowels and final consonants (U+1160-U+11FF)
119 * have a column width of 0.
121 * - Spacing characters in the East Asian Wide (W) or East Asian
122 * Full-width (F) category as defined in Unicode Technical
123 * Report #11 have a column width of 2.
125 * - All remaining characters (including all printable
126 * ISO 8859-1 and WGL4 characters, Unicode control characters,
127 * etc.) have a column width of 1.
129 * This implementation assumes that wchar_t characters are encoded
133 int wcwidth_ucs (wchar_t ucs)
135 /* sorted list of non-overlapping intervals of non-spacing characters */
136 /* generated by "uniset +cat=Me +cat=Mn +cat=Cf -00AD +1160-11FF +200B c" */
137 static const struct interval combining[] = {
138 { 0x0300, 0x0357 }, { 0x035D, 0x036F }, { 0x0483, 0x0486 },
139 { 0x0488, 0x0489 }, { 0x0591, 0x05A1 }, { 0x05A3, 0x05B9 },
140 { 0x05BB, 0x05BD }, { 0x05BF, 0x05BF }, { 0x05C1, 0x05C2 },
141 { 0x05C4, 0x05C4 }, { 0x0600, 0x0603 }, { 0x0610, 0x0615 },
142 { 0x064B, 0x0658 }, { 0x0670, 0x0670 }, { 0x06D6, 0x06E4 },
143 { 0x06E7, 0x06E8 }, { 0x06EA, 0x06ED }, { 0x070F, 0x070F },
144 { 0x0711, 0x0711 }, { 0x0730, 0x074A }, { 0x07A6, 0x07B0 },
145 { 0x0901, 0x0902 }, { 0x093C, 0x093C }, { 0x0941, 0x0948 },
146 { 0x094D, 0x094D }, { 0x0951, 0x0954 }, { 0x0962, 0x0963 },
147 { 0x0981, 0x0981 }, { 0x09BC, 0x09BC }, { 0x09C1, 0x09C4 },
148 { 0x09CD, 0x09CD }, { 0x09E2, 0x09E3 }, { 0x0A01, 0x0A02 },
149 { 0x0A3C, 0x0A3C }, { 0x0A41, 0x0A42 }, { 0x0A47, 0x0A48 },
150 { 0x0A4B, 0x0A4D }, { 0x0A70, 0x0A71 }, { 0x0A81, 0x0A82 },
151 { 0x0ABC, 0x0ABC }, { 0x0AC1, 0x0AC5 }, { 0x0AC7, 0x0AC8 },
152 { 0x0ACD, 0x0ACD }, { 0x0AE2, 0x0AE3 }, { 0x0B01, 0x0B01 },
153 { 0x0B3C, 0x0B3C }, { 0x0B3F, 0x0B3F }, { 0x0B41, 0x0B43 },
154 { 0x0B4D, 0x0B4D }, { 0x0B56, 0x0B56 }, { 0x0B82, 0x0B82 },
155 { 0x0BC0, 0x0BC0 }, { 0x0BCD, 0x0BCD }, { 0x0C3E, 0x0C40 },
156 { 0x0C46, 0x0C48 }, { 0x0C4A, 0x0C4D }, { 0x0C55, 0x0C56 },
157 { 0x0CBC, 0x0CBC }, { 0x0CBF, 0x0CBF }, { 0x0CC6, 0x0CC6 },
158 { 0x0CCC, 0x0CCD }, { 0x0D41, 0x0D43 }, { 0x0D4D, 0x0D4D },
159 { 0x0DCA, 0x0DCA }, { 0x0DD2, 0x0DD4 }, { 0x0DD6, 0x0DD6 },
160 { 0x0E31, 0x0E31 }, { 0x0E34, 0x0E3A }, { 0x0E47, 0x0E4E },
161 { 0x0EB1, 0x0EB1 }, { 0x0EB4, 0x0EB9 }, { 0x0EBB, 0x0EBC },
162 { 0x0EC8, 0x0ECD }, { 0x0F18, 0x0F19 }, { 0x0F35, 0x0F35 },
163 { 0x0F37, 0x0F37 }, { 0x0F39, 0x0F39 }, { 0x0F71, 0x0F7E },
164 { 0x0F80, 0x0F84 }, { 0x0F86, 0x0F87 }, { 0x0F90, 0x0F97 },
165 { 0x0F99, 0x0FBC }, { 0x0FC6, 0x0FC6 }, { 0x102D, 0x1030 },
166 { 0x1032, 0x1032 }, { 0x1036, 0x1037 }, { 0x1039, 0x1039 },
167 { 0x1058, 0x1059 }, { 0x1160, 0x11FF }, { 0x1712, 0x1714 },
168 { 0x1732, 0x1734 }, { 0x1752, 0x1753 }, { 0x1772, 0x1773 },
169 { 0x17B4, 0x17B5 }, { 0x17B7, 0x17BD }, { 0x17C6, 0x17C6 },
170 { 0x17C9, 0x17D3 }, { 0x17DD, 0x17DD }, { 0x180B, 0x180D },
171 { 0x18A9, 0x18A9 }, { 0x1920, 0x1922 }, { 0x1927, 0x1928 },
172 { 0x1932, 0x1932 }, { 0x1939, 0x193B }, { 0x200B, 0x200F },
173 { 0x202A, 0x202E }, { 0x2060, 0x2063 }, { 0x206A, 0x206F },
174 { 0x20D0, 0x20EA }, { 0x302A, 0x302F }, { 0x3099, 0x309A },
175 { 0xFB1E, 0xFB1E }, { 0xFE00, 0xFE0F }, { 0xFE20, 0xFE23 },
176 { 0xFEFF, 0xFEFF }, { 0xFFF9, 0xFFFB }, { 0x1D167, 0x1D169 },
177 { 0x1D173, 0x1D182 }, { 0x1D185, 0x1D18B }, { 0x1D1AA, 0x1D1AD },
178 { 0xE0001, 0xE0001 }, { 0xE0020, 0xE007F }, { 0xE0100, 0xE01EF }
181 /* test for 8-bit control characters */
184 if (ucs < 32 || (ucs >= 0x7f && ucs < 0xa0))
187 /* binary search in table of non-spacing characters */
188 if (bisearch(ucs, combining,
189 sizeof(combining) / sizeof(struct interval) - 1))
192 /* if we arrive here, ucs is not a combining or C0/C1 control character */
196 (ucs <= 0x115f || /* Hangul Jamo init. consonants */
197 ucs == 0x2329 || ucs == 0x232a ||
198 (ucs >= 0x2e80 && ucs <= 0xa4cf &&
199 ucs != 0x303f) || /* CJK ... Yi */
200 (ucs >= 0xac00 && ucs <= 0xd7a3) || /* Hangul Syllables */
201 (ucs >= 0xf900 && ucs <= 0xfaff) || /* CJK Compatibility Ideographs */
202 (ucs >= 0xfe30 && ucs <= 0xfe6f) || /* CJK Compatibility Forms */
203 (ucs >= 0xff00 && ucs <= 0xff60) || /* Fullwidth Forms */
204 (ucs >= 0xffe0 && ucs <= 0xffe6) ||
205 (ucs >= 0x20000 && ucs <= 0x2fffd) ||
206 (ucs >= 0x30000 && ucs <= 0x3fffd)));
209 #endif /* !HAVE_WC_FUNCS */