wcwidth.c

/*
 * A wrapper around wcswidth() to have it ignore characters which
 * are not represented in a particular output charset.
 */

#include <assert.h>
#include <stdlib.h>
#include "halibut.h"

#ifndef HAS_WCSWIDTH

/*
 * Markus Kuhn's public domain wcwidth() implementation, cribbed
 * from
 * 
 *   http://www.cl.cam.ac.uk/~mgk25/ucs/wcwidth.c
 */

#define wcswidth mk_wcswidth

struct interval {
    int first;
    int last;
};

/* auxiliary function for binary search in interval table */
static bool bisearch(wchar_t ucs, const struct interval *table, int max) {
    int min = 0;
    int mid;

    if (ucs < table[0].first || ucs > table[max].last)
	return false;
    while (max >= min) {
	mid = (min + max) / 2;
	if (ucs > table[mid].last)
	    min = mid + 1;
	else if (ucs < table[mid].first)
	    max = mid - 1;
	else
	    return true;
    }

    return false;
}

int mk_wcwidth(wchar_t ucs)
{
    /* sorted list of non-overlapping intervals of non-spacing characters */
    /* generated by "uniset +cat=Me +cat=Mn +cat=Cf -00AD +1160-11FF +200B c" */
    static const struct interval combining[] = {
	{ 0x0300, 0x0357 }, { 0x035D, 0x036F }, { 0x0483, 0x0486 },
	{ 0x0488, 0x0489 }, { 0x0591, 0x05A1 }, { 0x05A3, 0x05B9 },
    { 0x05BB, 0x05BD }, { 0x05BF, 0x05BF }, { 0x05C1, 0x05C2 },
    { 0x05C4, 0x05C4 }, { 0x0600, 0x0603 }, { 0x0610, 0x0615 },
    { 0x064B, 0x0658 }, { 0x0670, 0x0670 }, { 0x06D6, 0x06E4 },
    { 0x06E7, 0x06E8 }, { 0x06EA, 0x06ED }, { 0x070F, 0x070F },
    { 0x0711, 0x0711 }, { 0x0730, 0x074A }, { 0x07A6, 0x07B0 },
    { 0x0901, 0x0902 }, { 0x093C, 0x093C }, { 0x0941, 0x0948 },
    { 0x094D, 0x094D }, { 0x0951, 0x0954 }, { 0x0962, 0x0963 },
    { 0x0981, 0x0981 }, { 0x09BC, 0x09BC }, { 0x09C1, 0x09C4 },
    { 0x09CD, 0x09CD }, { 0x09E2, 0x09E3 }, { 0x0A01, 0x0A02 },
    { 0x0A3C, 0x0A3C }, { 0x0A41, 0x0A42 }, { 0x0A47, 0x0A48 },
    { 0x0A4B, 0x0A4D }, { 0x0A70, 0x0A71 }, { 0x0A81, 0x0A82 },
    { 0x0ABC, 0x0ABC }, { 0x0AC1, 0x0AC5 }, { 0x0AC7, 0x0AC8 },
    { 0x0ACD, 0x0ACD }, { 0x0AE2, 0x0AE3 }, { 0x0B01, 0x0B01 },
    { 0x0B3C, 0x0B3C }, { 0x0B3F, 0x0B3F }, { 0x0B41, 0x0B43 },
    { 0x0B4D, 0x0B4D }, { 0x0B56, 0x0B56 }, { 0x0B82, 0x0B82 },
    { 0x0BC0, 0x0BC0 }, { 0x0BCD, 0x0BCD }, { 0x0C3E, 0x0C40 },
    { 0x0C46, 0x0C48 }, { 0x0C4A, 0x0C4D }, { 0x0C55, 0x0C56 },
    { 0x0CBC, 0x0CBC }, { 0x0CBF, 0x0CBF }, { 0x0CC6, 0x0CC6 },
    { 0x0CCC, 0x0CCD }, { 0x0D41, 0x0D43 }, { 0x0D4D, 0x0D4D },
    { 0x0DCA, 0x0DCA }, { 0x0DD2, 0x0DD4 }, { 0x0DD6, 0x0DD6 },
    { 0x0E31, 0x0E31 }, { 0x0E34, 0x0E3A }, { 0x0E47, 0x0E4E },
    { 0x0EB1, 0x0EB1 }, { 0x0EB4, 0x0EB9 }, { 0x0EBB, 0x0EBC },
    { 0x0EC8, 0x0ECD }, { 0x0F18, 0x0F19 }, { 0x0F35, 0x0F35 },
    { 0x0F37, 0x0F37 }, { 0x0F39, 0x0F39 }, { 0x0F71, 0x0F7E },
    { 0x0F80, 0x0F84 }, { 0x0F86, 0x0F87 }, { 0x0F90, 0x0F97 },
    { 0x0F99, 0x0FBC }, { 0x0FC6, 0x0FC6 }, { 0x102D, 0x1030 },
    { 0x1032, 0x1032 }, { 0x1036, 0x1037 }, { 0x1039, 0x1039 },
    { 0x1058, 0x1059 }, { 0x1160, 0x11FF }, { 0x1712, 0x1714 },
    { 0x1732, 0x1734 }, { 0x1752, 0x1753 }, { 0x1772, 0x1773 },
    { 0x17B4, 0x17B5 }, { 0x17B7, 0x17BD }, { 0x17C6, 0x17C6 },
    { 0x17C9, 0x17D3 }, { 0x17DD, 0x17DD }, { 0x180B, 0x180D },
    { 0x18A9, 0x18A9 }, { 0x1920, 0x1922 }, { 0x1927, 0x1928 },
    { 0x1932, 0x1932 }, { 0x1939, 0x193B }, { 0x200B, 0x200F },
    { 0x202A, 0x202E }, { 0x2060, 0x2063 }, { 0x206A, 0x206F },
    { 0x20D0, 0x20EA }, { 0x302A, 0x302F }, { 0x3099, 0x309A },
    { 0xFB1E, 0xFB1E }, { 0xFE00, 0xFE0F }, { 0xFE20, 0xFE23 },
    { 0xFEFF, 0xFEFF }, { 0xFFF9, 0xFFFB }, { 0x1D167, 0x1D169 },
    { 0x1D173, 0x1D182 }, { 0x1D185, 0x1D18B }, { 0x1D1AA, 0x1D1AD },
    { 0xE0001, 0xE0001 }, { 0xE0020, 0xE007F }, { 0xE0100, 0xE01EF }
  };

  /* test for 8-bit control characters */
  if (ucs == 0)
    return 0;
  if (ucs < 32 || (ucs >= 0x7f && ucs < 0xa0))
    return -1;

  /* binary search in table of non-spacing characters */
  if (bisearch(ucs, combining,
	       sizeof(combining) / sizeof(struct interval) - 1))
    return 0;

  /* if we arrive here, ucs is not a combining or C0/C1 control character */

  return 1 + 
    (ucs >= 0x1100 &&
     (ucs <= 0x115f ||                    /* Hangul Jamo init. consonants */
      ucs == 0x2329 || ucs == 0x232a ||
      (ucs >= 0x2e80 && ucs <= 0xa4cf &&
       ucs != 0x303f) ||                  /* CJK ... Yi */
      (ucs >= 0xac00 && ucs <= 0xd7a3) || /* Hangul Syllables */
      (ucs >= 0xf900 && ucs <= 0xfaff) || /* CJK Compatibility Ideographs */
      (ucs >= 0xfe30 && ucs <= 0xfe6f) || /* CJK Compatibility Forms */
      (ucs >= 0xff00 && ucs <= 0xff60) || /* Fullwidth Forms */
      (ucs >= 0xffe0 && ucs <= 0xffe6) ||
      (ucs >= 0x20000 && ucs <= 0x2fffd) ||
      (ucs >= 0x30000 && ucs <= 0x3fffd)));
}


int mk_wcswidth(const wchar_t *pwcs, size_t n)
{
  int w, width = 0;

  for (; n-- > 0 && *pwcs; pwcs++)
    if ((w = mk_wcwidth(*pwcs)) < 0)
      return -1;
    else
      width += w;

  return width;
}

#endif

int ustrwid(wchar_t const *s, int charset)
{
    char buf[256];
    int wid, len = ustrlen(s);
    charset_state state = CHARSET_INIT_STATE;

    wid = 0;

    while (len > 0) {
	bool err;
	wchar_t const *s_orig;

	err = false;
	s_orig = s;
        charset_from_unicode(&s, &len, buf, lenof(buf), charset, &state, &err);
	wid += wcswidth(s_orig, s - s_orig);
	if (err) {
	    assert(len > 0 && *s);
	    s++;
	    len--;
	}
    }

    return wid;
}

int strwid(char const *s, int charset)
{
    wchar_t buf[256];
    int wid, len = strlen(s);
    charset_state state = CHARSET_INIT_STATE;

    wid = 0;

    while (len > 0) {
	int ret;

	ret = charset_to_unicode(&s, &len, buf, lenof(buf),
				 charset, &state, NULL, 0);

	if (ret > 0)
	    wid += wcswidth(buf, ret);
    }

    return wid;
}