wcwidth.js

/*
wcwidth.js: JavaScript Portng of Markus Kuhn's wcwidth() Implementation
=======================================================================

Copyright (C) 2012 by Jun Woong.

This package is a JavaScript porting of `wcwidth()` implementation
[by Markus Kuhn](http://www.cl.cam.ac.uk/~mgk25/ucs/wcwidth.c).

Permission is hereby granted, free of charge, to any person obtaining a copy of
this software and associated documentation files (the "Software"), to deal in
the Software without restriction, including without limitation the rights to
use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
of the Software, and to permit persons to whom the Software is furnished to do
so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.


THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR
OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
POSSIBILITY OF SUCH DAMAGE.
*/

"use strict"

var punycode = require('punycode');

exports = module.exports = wcswidth;
exports.wcwidth = wcwidth;

var combining = [
  [ 0x0300, 0x036F ], [ 0x0483, 0x0486 ], [ 0x0488, 0x0489 ],
  [ 0x0591, 0x05BD ], [ 0x05BF, 0x05BF ], [ 0x05C1, 0x05C2 ],
  [ 0x05C4, 0x05C5 ], [ 0x05C7, 0x05C7 ], [ 0x0600, 0x0603 ],
  [ 0x0610, 0x0615 ], [ 0x064B, 0x065E ], [ 0x0670, 0x0670 ],
  [ 0x06D6, 0x06E4 ], [ 0x06E7, 0x06E8 ], [ 0x06EA, 0x06ED ],
  [ 0x070F, 0x070F ], [ 0x0711, 0x0711 ], [ 0x0730, 0x074A ],
  [ 0x07A6, 0x07B0 ], [ 0x07EB, 0x07F3 ], [ 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 ],
  [ 0x0CE2, 0x0CE3 ], [ 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 ], [ 0x135F, 0x135F ],
  [ 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 ],
  [ 0x1A17, 0x1A18 ], [ 0x1B00, 0x1B03 ], [ 0x1B34, 0x1B34 ],
  [ 0x1B36, 0x1B3A ], [ 0x1B3C, 0x1B3C ], [ 0x1B42, 0x1B42 ],
  [ 0x1B6B, 0x1B73 ], [ 0x1DC0, 0x1DCA ], [ 0x1DFE, 0x1DFF ],
  [ 0x200B, 0x200F ], [ 0x202A, 0x202E ], [ 0x2060, 0x2063 ],
  [ 0x206A, 0x206F ], [ 0x20D0, 0x20EF ], [ 0x302A, 0x302F ],
  [ 0x3099, 0x309A ], [ 0xA806, 0xA806 ], [ 0xA80B, 0xA80B ],
  [ 0xA825, 0xA826 ], [ 0xFB1E, 0xFB1E ], [ 0xFE00, 0xFE0F ],
  [ 0xFE20, 0xFE23 ], [ 0xFEFF, 0xFEFF ], [ 0xFFF9, 0xFFFB ],
  [ 0x10A01, 0x10A03 ], [ 0x10A05, 0x10A06 ], [ 0x10A0C, 0x10A0F ],
  [ 0x10A38, 0x10A3A ], [ 0x10A3F, 0x10A3F ], [ 0x1D167, 0x1D169 ],
  [ 0x1D173, 0x1D182 ], [ 0x1D185, 0x1D18B ], [ 0x1D1AA, 0x1D1AD ],
  [ 0x1D242, 0x1D244 ], [ 0xE0001, 0xE0001 ], [ 0xE0020, 0xE007F ],
  [ 0xE0100, 0xE01EF ]
];

var opts = {
  nul: 0,
  control: 0
};

/*
 *  The following functions define the column width of an ISO 10646
 *  character as follows:
 *  - The null character (U+0000) has a column width of 0.
 *  - Other C0/C1 control characters and DEL will lead to a return value
 *    of -1.
 *  - Non-spacing and enclosing combining characters (general category
 *    code Mn or Me in the
 *    Unicode database) have a column width of 0.
 *  - SOFT HYPHEN (U+00AD) has a column width of 1.
 *  - Other format characters (general category code Cf in the Unicode
 *    database) and ZERO WIDTH
 *    SPACE (U+200B) have a column width of 0.
 *  - Hangul Jamo medial vowels and final consonants (U+1160-U+11FF)
 *    have a column width of 0.
 *  - Spacing characters in the East Asian Wide (W) or East Asian
 *    Full-width (F) category as
 *    defined in Unicode Technical Report #11 have a column width of 2.
 *  - All remaining characters (including all printable ISO 8859-1 and
 *    WGL4 characters, Unicode control characters, etc.) have a column
 *    width of 1.
 *  This implementation assumes that characters are encoded in ISO 10646.
*/

function wcswidth(str) {
  if (typeof str !== 'string') return wcwidth(str);

  var s = 0;
  var codePoints = punycode.ucs2.decode(str);
  for (var i = 0; i < codePoints.length; i++) {
    var n = wcwidth(codePoints[i]);
    if (n < 0) return -1;
    s += n;
  }

  return s;
}

function wcwidth(ucs) {
  // test for 8-bit control characters
  if (ucs === 0) return opts.nul;
  if (ucs < 32 || (ucs >= 0x7f && ucs < 0xa0)) return opts.control;

  // binary search in table of non-spacing characters
  if (bisearch(ucs)) 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 >= 0xfe10 && ucs <= 0xfe19) ||    // Vertical forms
        (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)));
}

function bisearch(ucs) {
  var min = 0;
  var max = combining.length - 1;
  var mid;

  if (ucs < combining[0][0] || ucs > combining[max][1]) return false;

  while (max >= min) {
    mid = Math.floor((min + max) / 2);
    if (ucs > combining[mid][1]) min = mid + 1;
    else if (ucs < combining[mid][0]) max = mid - 1;
    else return true;
  }

  return false;
}