1 |
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2 |
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3 | var defaults = require('defaults')
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4 | var combining = require('./combining')
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5 |
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6 | var DEFAULTS = {
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7 | nul: 0,
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8 | control: 0
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9 | }
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10 |
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11 | module.exports = function wcwidth(str) {
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12 | return wcswidth(str, DEFAULTS)
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13 | }
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14 |
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15 | module.exports.config = function(opts) {
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16 | opts = defaults(opts || {}, DEFAULTS)
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17 | return function wcwidth(str) {
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18 | return wcswidth(str, opts)
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19 | }
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20 | }
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21 |
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22 | /*
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23 | * The following functions define the column width of an ISO 10646
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24 | * character as follows:
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25 | * - The null character (U+0000) has a column width of 0.
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26 | * - Other C0/C1 control characters and DEL will lead to a return value
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27 | * of -1.
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28 | * - Non-spacing and enclosing combining characters (general category
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29 | * code Mn or Me in the
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30 | * Unicode database) have a column width of 0.
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31 | * - SOFT HYPHEN (U+00AD) has a column width of 1.
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32 | * - Other format characters (general category code Cf in the Unicode
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33 | * database) and ZERO WIDTH
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34 | * SPACE (U+200B) have a column width of 0.
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35 | * - Hangul Jamo medial vowels and final consonants (U+1160-U+11FF)
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36 | * have a column width of 0.
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37 | * - Spacing characters in the East Asian Wide (W) or East Asian
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38 | * Full-width (F) category as
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39 | * defined in Unicode Technical Report #11 have a column width of 2.
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40 | * - All remaining characters (including all printable ISO 8859-1 and
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41 | * WGL4 characters, Unicode control characters, etc.) have a column
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42 | * width of 1.
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43 | * This implementation assumes that characters are encoded in ISO 10646.
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44 | */
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45 |
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46 | function wcswidth(str, opts) {
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47 | if (typeof str !== 'string') return wcwidth(str, opts)
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48 |
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49 | var s = 0
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50 | for (var i = 0; i < str.length; i++) {
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51 | var n = wcwidth(str.charCodeAt(i), opts)
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52 | if (n < 0) return -1
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53 | s += n
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54 | }
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55 |
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56 | return s
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57 | }
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58 |
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59 | function wcwidth(ucs, opts) {
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60 | // test for 8-bit control characters
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61 | if (ucs === 0) return opts.nul
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62 | if (ucs < 32 || (ucs >= 0x7f && ucs < 0xa0)) return opts.control
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63 |
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64 | // binary search in table of non-spacing characters
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65 | if (bisearch(ucs)) return 0
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66 |
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67 | // if we arrive here, ucs is not a combining or C0/C1 control character
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68 | return 1 +
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69 | (ucs >= 0x1100 &&
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70 | (ucs <= 0x115f || // Hangul Jamo init. consonants
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71 | ucs == 0x2329 || ucs == 0x232a ||
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72 | (ucs >= 0x2e80 && ucs <= 0xa4cf &&
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73 | ucs != 0x303f) || // CJK ... Yi
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74 | (ucs >= 0xac00 && ucs <= 0xd7a3) || // Hangul Syllables
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75 | (ucs >= 0xf900 && ucs <= 0xfaff) || // CJK Compatibility Ideographs
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76 | (ucs >= 0xfe10 && ucs <= 0xfe19) || // Vertical forms
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77 | (ucs >= 0xfe30 && ucs <= 0xfe6f) || // CJK Compatibility Forms
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78 | (ucs >= 0xff00 && ucs <= 0xff60) || // Fullwidth Forms
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79 | (ucs >= 0xffe0 && ucs <= 0xffe6) ||
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80 | (ucs >= 0x20000 && ucs <= 0x2fffd) ||
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81 | (ucs >= 0x30000 && ucs <= 0x3fffd)));
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82 | }
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83 |
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84 | function bisearch(ucs) {
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85 | var min = 0
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86 | var max = combining.length - 1
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87 | var mid
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88 |
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89 | if (ucs < combining[0][0] || ucs > combining[max][1]) return false
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90 |
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91 | while (max >= min) {
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92 | mid = Math.floor((min + max) / 2)
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93 | if (ucs > combining[mid][1]) min = mid + 1
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94 | else if (ucs < combining[mid][0]) max = mid - 1
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95 | else return true
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96 | }
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97 |
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98 | return false
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99 | }
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