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readline 6.3

    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 -- 2007-05-26 (Unicode 5.0)
   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: #ifdef __GO32__
   63: #  include <wctype.h>
   64: #endif
   65: 
   66: #include <wchar.h>
   67: 
   68: struct interval {
   69:   int first;
   70:   int last;
   71: };
   72: 
   73: /* auxiliary function for binary search in interval table */
   74: static int bisearch(wchar_t ucs, const struct interval *table, int max) {
   75:   int min = 0;
   76:   int mid;
   77: 
   78:   if (ucs < table[0].first || ucs > table[max].last)
   79:     return 0;
   80:   while (max >= min) {
   81:     mid = (min + max) / 2;
   82:     if (ucs > table[mid].last)
   83:       min = mid + 1;
   84:     else if (ucs < table[mid].first)
   85:       max = mid - 1;
   86:     else
   87:       return 1;
   88:   }
   89: 
   90:   return 0;
   91: }
   92: 
   93: 
   94: /* The following two functions define the column width of an ISO 10646
   95:  * character as follows:
   96:  *
   97:  *    - The null character (U+0000) has a column width of 0.
   98:  *
   99:  *    - Other C0/C1 control characters and DEL will lead to a return
  100:  *      value of -1.
  101:  *
  102:  *    - Non-spacing and enclosing combining characters (general
  103:  *      category code Mn or Me in the Unicode database) have a
  104:  *      column width of 0.
  105:  *
  106:  *    - SOFT HYPHEN (U+00AD) has a column width of 1.
  107:  *
  108:  *    - Other format characters (general category code Cf in the Unicode
  109:  *      database) and ZERO WIDTH SPACE (U+200B) have a column width of 0.
  110:  *
  111:  *    - Hangul Jamo medial vowels and final consonants (U+1160-U+11FF)
  112:  *      have a column width of 0.
  113:  *
  114:  *    - Spacing characters in the East Asian Wide (W) or East Asian
  115:  *      Full-width (F) category as defined in Unicode Technical
  116:  *      Report #11 have a column width of 2.
  117:  *
  118:  *    - All remaining characters (including all printable
  119:  *      ISO 8859-1 and WGL4 characters, Unicode control characters,
  120:  *      etc.) have a column width of 1.
  121:  *
  122:  * This implementation assumes that wchar_t characters are encoded
  123:  * in ISO 10646.
  124:  */
  125: 
  126: int mk_wcwidth(wchar_t ucs)
  127: {
  128:   /* sorted list of non-overlapping intervals of non-spacing characters */
  129:   /* generated by "uniset +cat=Me +cat=Mn +cat=Cf -00AD +1160-11FF +200B c" */
  130:   static const struct interval combining[] = {
  131:     { 0x0300, 0x036F }, { 0x0483, 0x0486 }, { 0x0488, 0x0489 },
  132:     { 0x0591, 0x05BD }, { 0x05BF, 0x05BF }, { 0x05C1, 0x05C2 },
  133:     { 0x05C4, 0x05C5 }, { 0x05C7, 0x05C7 }, { 0x0600, 0x0603 },
  134:     { 0x0610, 0x0615 }, { 0x064B, 0x065E }, { 0x0670, 0x0670 },
  135:     { 0x06D6, 0x06E4 }, { 0x06E7, 0x06E8 }, { 0x06EA, 0x06ED },
  136:     { 0x070F, 0x070F }, { 0x0711, 0x0711 }, { 0x0730, 0x074A },
  137:     { 0x07A6, 0x07B0 }, { 0x07EB, 0x07F3 }, { 0x0901, 0x0902 },
  138:     { 0x093C, 0x093C }, { 0x0941, 0x0948 }, { 0x094D, 0x094D },
  139:     { 0x0951, 0x0954 }, { 0x0962, 0x0963 }, { 0x0981, 0x0981 },
  140:     { 0x09BC, 0x09BC }, { 0x09C1, 0x09C4 }, { 0x09CD, 0x09CD },
  141:     { 0x09E2, 0x09E3 }, { 0x0A01, 0x0A02 }, { 0x0A3C, 0x0A3C },
  142:     { 0x0A41, 0x0A42 }, { 0x0A47, 0x0A48 }, { 0x0A4B, 0x0A4D },
  143:     { 0x0A70, 0x0A71 }, { 0x0A81, 0x0A82 }, { 0x0ABC, 0x0ABC },
  144:     { 0x0AC1, 0x0AC5 }, { 0x0AC7, 0x0AC8 }, { 0x0ACD, 0x0ACD },
  145:     { 0x0AE2, 0x0AE3 }, { 0x0B01, 0x0B01 }, { 0x0B3C, 0x0B3C },
  146:     { 0x0B3F, 0x0B3F }, { 0x0B41, 0x0B43 }, { 0x0B4D, 0x0B4D },
  147:     { 0x0B56, 0x0B56 }, { 0x0B82, 0x0B82 }, { 0x0BC0, 0x0BC0 },
  148:     { 0x0BCD, 0x0BCD }, { 0x0C3E, 0x0C40 }, { 0x0C46, 0x0C48 },
  149:     { 0x0C4A, 0x0C4D }, { 0x0C55, 0x0C56 }, { 0x0CBC, 0x0CBC },
  150:     { 0x0CBF, 0x0CBF }, { 0x0CC6, 0x0CC6 }, { 0x0CCC, 0x0CCD },
  151:     { 0x0CE2, 0x0CE3 }, { 0x0D41, 0x0D43 }, { 0x0D4D, 0x0D4D },
  152:     { 0x0DCA, 0x0DCA }, { 0x0DD2, 0x0DD4 }, { 0x0DD6, 0x0DD6 },
  153:     { 0x0E31, 0x0E31 }, { 0x0E34, 0x0E3A }, { 0x0E47, 0x0E4E },
  154:     { 0x0EB1, 0x0EB1 }, { 0x0EB4, 0x0EB9 }, { 0x0EBB, 0x0EBC },
  155:     { 0x0EC8, 0x0ECD }, { 0x0F18, 0x0F19 }, { 0x0F35, 0x0F35 },
  156:     { 0x0F37, 0x0F37 }, { 0x0F39, 0x0F39 }, { 0x0F71, 0x0F7E },
  157:     { 0x0F80, 0x0F84 }, { 0x0F86, 0x0F87 }, { 0x0F90, 0x0F97 },
  158:     { 0x0F99, 0x0FBC }, { 0x0FC6, 0x0FC6 }, { 0x102D, 0x1030 },
  159:     { 0x1032, 0x1032 }, { 0x1036, 0x1037 }, { 0x1039, 0x1039 },
  160:     { 0x1058, 0x1059 }, { 0x1160, 0x11FF }, { 0x135F, 0x135F },
  161:     { 0x1712, 0x1714 }, { 0x1732, 0x1734 }, { 0x1752, 0x1753 },
  162:     { 0x1772, 0x1773 }, { 0x17B4, 0x17B5 }, { 0x17B7, 0x17BD },
  163:     { 0x17C6, 0x17C6 }, { 0x17C9, 0x17D3 }, { 0x17DD, 0x17DD },
  164:     { 0x180B, 0x180D }, { 0x18A9, 0x18A9 }, { 0x1920, 0x1922 },
  165:     { 0x1927, 0x1928 }, { 0x1932, 0x1932 }, { 0x1939, 0x193B },
  166:     { 0x1A17, 0x1A18 }, { 0x1B00, 0x1B03 }, { 0x1B34, 0x1B34 },
  167:     { 0x1B36, 0x1B3A }, { 0x1B3C, 0x1B3C }, { 0x1B42, 0x1B42 },
  168:     { 0x1B6B, 0x1B73 }, { 0x1DC0, 0x1DCA }, { 0x1DFE, 0x1DFF },
  169:     { 0x200B, 0x200F }, { 0x202A, 0x202E }, { 0x2060, 0x2063 },
  170:     { 0x206A, 0x206F }, { 0x20D0, 0x20EF }, { 0x302A, 0x302F },
  171:     { 0x3099, 0x309A }, { 0xA806, 0xA806 }, { 0xA80B, 0xA80B },
  172:     { 0xA825, 0xA826 }, { 0xFB1E, 0xFB1E }, { 0xFE00, 0xFE0F },
  173:     { 0xFE20, 0xFE23 }, { 0xFEFF, 0xFEFF }, { 0xFFF9, 0xFFFB },
  174:     { 0x10A01, 0x10A03 }, { 0x10A05, 0x10A06 }, { 0x10A0C, 0x10A0F },
  175:     { 0x10A38, 0x10A3A }, { 0x10A3F, 0x10A3F }, { 0x1D167, 0x1D169 },
  176:     { 0x1D173, 0x1D182 }, { 0x1D185, 0x1D18B }, { 0x1D1AA, 0x1D1AD },
  177:     { 0x1D242, 0x1D244 }, { 0xE0001, 0xE0001 }, { 0xE0020, 0xE007F },
  178:     { 0xE0100, 0xE01EF }
  179:   };
  180: 
  181:   /* test for 8-bit control characters */
  182:   if (ucs == 0)
  183:     return 0;
  184:   if (ucs < 32 || (ucs >= 0x7f && ucs < 0xa0))
  185:     return -1;
  186: 
  187:   /* binary search in table of non-spacing characters */
  188:   if (bisearch(ucs, combining,
  189: 	       sizeof(combining) / sizeof(struct interval) - 1))
  190:     return 0;
  191: 
  192:   /* if we arrive here, ucs is not a combining or C0/C1 control character */
  193: 
  194:   return 1 + 
  195:     (ucs >= 0x1100 &&
  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 >= 0xfe10 && ucs <= 0xfe19) || /* Vertical forms */
  203:       (ucs >= 0xfe30 && ucs <= 0xfe6f) || /* CJK Compatibility Forms */
  204:       (ucs >= 0xff00 && ucs <= 0xff60) || /* Fullwidth Forms */
  205:       (ucs >= 0xffe0 && ucs <= 0xffe6) ||
  206:       (ucs >= 0x20000 && ucs <= 0x2fffd) ||
  207:       (ucs >= 0x30000 && ucs <= 0x3fffd)));
  208: }
  209: 
  210: 
  211: int mk_wcswidth(const wchar_t *pwcs, size_t n)
  212: {
  213:   int w, width = 0;
  214: 
  215:   for (;*pwcs && n-- > 0; pwcs++)
  216:     if ((w = mk_wcwidth(*pwcs)) < 0)
  217:       return -1;
  218:     else
  219:       width += w;
  220: 
  221:   return width;
  222: }
  223: 
  224: 
  225: /*
  226:  * The following functions are the same as mk_wcwidth() and
  227:  * mk_wcswidth(), except that spacing characters in the East Asian
  228:  * Ambiguous (A) category as defined in Unicode Technical Report #11
  229:  * have a column width of 2. This variant might be useful for users of
  230:  * CJK legacy encodings who want to migrate to UCS without changing
  231:  * the traditional terminal character-width behaviour. It is not
  232:  * otherwise recommended for general use.
  233:  */
  234: int mk_wcwidth_cjk(wchar_t ucs)
  235: {
  236:   /* sorted list of non-overlapping intervals of East Asian Ambiguous
  237:    * characters, generated by "uniset +WIDTH-A -cat=Me -cat=Mn -cat=Cf c" */
  238:   static const struct interval ambiguous[] = {
  239:     { 0x00A1, 0x00A1 }, { 0x00A4, 0x00A4 }, { 0x00A7, 0x00A8 },
  240:     { 0x00AA, 0x00AA }, { 0x00AE, 0x00AE }, { 0x00B0, 0x00B4 },
  241:     { 0x00B6, 0x00BA }, { 0x00BC, 0x00BF }, { 0x00C6, 0x00C6 },
  242:     { 0x00D0, 0x00D0 }, { 0x00D7, 0x00D8 }, { 0x00DE, 0x00E1 },
  243:     { 0x00E6, 0x00E6 }, { 0x00E8, 0x00EA }, { 0x00EC, 0x00ED },
  244:     { 0x00F0, 0x00F0 }, { 0x00F2, 0x00F3 }, { 0x00F7, 0x00FA },
  245:     { 0x00FC, 0x00FC }, { 0x00FE, 0x00FE }, { 0x0101, 0x0101 },
  246:     { 0x0111, 0x0111 }, { 0x0113, 0x0113 }, { 0x011B, 0x011B },
  247:     { 0x0126, 0x0127 }, { 0x012B, 0x012B }, { 0x0131, 0x0133 },
  248:     { 0x0138, 0x0138 }, { 0x013F, 0x0142 }, { 0x0144, 0x0144 },
  249:     { 0x0148, 0x014B }, { 0x014D, 0x014D }, { 0x0152, 0x0153 },
  250:     { 0x0166, 0x0167 }, { 0x016B, 0x016B }, { 0x01CE, 0x01CE },
  251:     { 0x01D0, 0x01D0 }, { 0x01D2, 0x01D2 }, { 0x01D4, 0x01D4 },
  252:     { 0x01D6, 0x01D6 }, { 0x01D8, 0x01D8 }, { 0x01DA, 0x01DA },
  253:     { 0x01DC, 0x01DC }, { 0x0251, 0x0251 }, { 0x0261, 0x0261 },
  254:     { 0x02C4, 0x02C4 }, { 0x02C7, 0x02C7 }, { 0x02C9, 0x02CB },
  255:     { 0x02CD, 0x02CD }, { 0x02D0, 0x02D0 }, { 0x02D8, 0x02DB },
  256:     { 0x02DD, 0x02DD }, { 0x02DF, 0x02DF }, { 0x0391, 0x03A1 },
  257:     { 0x03A3, 0x03A9 }, { 0x03B1, 0x03C1 }, { 0x03C3, 0x03C9 },
  258:     { 0x0401, 0x0401 }, { 0x0410, 0x044F }, { 0x0451, 0x0451 },
  259:     { 0x2010, 0x2010 }, { 0x2013, 0x2016 }, { 0x2018, 0x2019 },
  260:     { 0x201C, 0x201D }, { 0x2020, 0x2022 }, { 0x2024, 0x2027 },
  261:     { 0x2030, 0x2030 }, { 0x2032, 0x2033 }, { 0x2035, 0x2035 },
  262:     { 0x203B, 0x203B }, { 0x203E, 0x203E }, { 0x2074, 0x2074 },
  263:     { 0x207F, 0x207F }, { 0x2081, 0x2084 }, { 0x20AC, 0x20AC },
  264:     { 0x2103, 0x2103 }, { 0x2105, 0x2105 }, { 0x2109, 0x2109 },
  265:     { 0x2113, 0x2113 }, { 0x2116, 0x2116 }, { 0x2121, 0x2122 },
  266:     { 0x2126, 0x2126 }, { 0x212B, 0x212B }, { 0x2153, 0x2154 },
  267:     { 0x215B, 0x215E }, { 0x2160, 0x216B }, { 0x2170, 0x2179 },
  268:     { 0x2190, 0x2199 }, { 0x21B8, 0x21B9 }, { 0x21D2, 0x21D2 },
  269:     { 0x21D4, 0x21D4 }, { 0x21E7, 0x21E7 }, { 0x2200, 0x2200 },
  270:     { 0x2202, 0x2203 }, { 0x2207, 0x2208 }, { 0x220B, 0x220B },
  271:     { 0x220F, 0x220F }, { 0x2211, 0x2211 }, { 0x2215, 0x2215 },
  272:     { 0x221A, 0x221A }, { 0x221D, 0x2220 }, { 0x2223, 0x2223 },
  273:     { 0x2225, 0x2225 }, { 0x2227, 0x222C }, { 0x222E, 0x222E },
  274:     { 0x2234, 0x2237 }, { 0x223C, 0x223D }, { 0x2248, 0x2248 },
  275:     { 0x224C, 0x224C }, { 0x2252, 0x2252 }, { 0x2260, 0x2261 },
  276:     { 0x2264, 0x2267 }, { 0x226A, 0x226B }, { 0x226E, 0x226F },
  277:     { 0x2282, 0x2283 }, { 0x2286, 0x2287 }, { 0x2295, 0x2295 },
  278:     { 0x2299, 0x2299 }, { 0x22A5, 0x22A5 }, { 0x22BF, 0x22BF },
  279:     { 0x2312, 0x2312 }, { 0x2460, 0x24E9 }, { 0x24EB, 0x254B },
  280:     { 0x2550, 0x2573 }, { 0x2580, 0x258F }, { 0x2592, 0x2595 },
  281:     { 0x25A0, 0x25A1 }, { 0x25A3, 0x25A9 }, { 0x25B2, 0x25B3 },
  282:     { 0x25B6, 0x25B7 }, { 0x25BC, 0x25BD }, { 0x25C0, 0x25C1 },
  283:     { 0x25C6, 0x25C8 }, { 0x25CB, 0x25CB }, { 0x25CE, 0x25D1 },
  284:     { 0x25E2, 0x25E5 }, { 0x25EF, 0x25EF }, { 0x2605, 0x2606 },
  285:     { 0x2609, 0x2609 }, { 0x260E, 0x260F }, { 0x2614, 0x2615 },
  286:     { 0x261C, 0x261C }, { 0x261E, 0x261E }, { 0x2640, 0x2640 },
  287:     { 0x2642, 0x2642 }, { 0x2660, 0x2661 }, { 0x2663, 0x2665 },
  288:     { 0x2667, 0x266A }, { 0x266C, 0x266D }, { 0x266F, 0x266F },
  289:     { 0x273D, 0x273D }, { 0x2776, 0x277F }, { 0xE000, 0xF8FF },
  290:     { 0xFFFD, 0xFFFD }, { 0xF0000, 0xFFFFD }, { 0x100000, 0x10FFFD }
  291:   };
  292: 
  293:   /* binary search in table of non-spacing characters */
  294:   if (bisearch(ucs, ambiguous,
  295: 	       sizeof(ambiguous) / sizeof(struct interval) - 1))
  296:     return 2;
  297: 
  298:   return mk_wcwidth(ucs);
  299: }
  300: 
  301: 
  302: int mk_wcswidth_cjk(const wchar_t *pwcs, size_t n)
  303: {
  304:   int w, width = 0;
  305: 
  306:   for (;*pwcs && n-- > 0; pwcs++)
  307:     if ((w = mk_wcwidth_cjk(*pwcs)) < 0)
  308:       return -1;
  309:     else
  310:       width += w;
  311: 
  312:   return width;
  313: }