| 'use strict'; | 
| /* eslint-disable yoda */ | 
| module.exports = x => { | 
|     if (Number.isNaN(x)) { | 
|         return false; | 
|     } | 
|   | 
|     // code points are derived from: | 
|     // http://www.unix.org/Public/UNIDATA/EastAsianWidth.txt | 
|     if ( | 
|         x >= 0x1100 && ( | 
|             x <= 0x115f ||  // Hangul Jamo | 
|             x === 0x2329 || // LEFT-POINTING ANGLE BRACKET | 
|             x === 0x232a || // RIGHT-POINTING ANGLE BRACKET | 
|             // CJK Radicals Supplement .. Enclosed CJK Letters and Months | 
|             (0x2e80 <= x && x <= 0x3247 && x !== 0x303f) || | 
|             // Enclosed CJK Letters and Months .. CJK Unified Ideographs Extension A | 
|             (0x3250 <= x && x <= 0x4dbf) || | 
|             // CJK Unified Ideographs .. Yi Radicals | 
|             (0x4e00 <= x && x <= 0xa4c6) || | 
|             // Hangul Jamo Extended-A | 
|             (0xa960 <= x && x <= 0xa97c) || | 
|             // Hangul Syllables | 
|             (0xac00 <= x && x <= 0xd7a3) || | 
|             // CJK Compatibility Ideographs | 
|             (0xf900 <= x && x <= 0xfaff) || | 
|             // Vertical Forms | 
|             (0xfe10 <= x && x <= 0xfe19) || | 
|             // CJK Compatibility Forms .. Small Form Variants | 
|             (0xfe30 <= x && x <= 0xfe6b) || | 
|             // Halfwidth and Fullwidth Forms | 
|             (0xff01 <= x && x <= 0xff60) || | 
|             (0xffe0 <= x && x <= 0xffe6) || | 
|             // Kana Supplement | 
|             (0x1b000 <= x && x <= 0x1b001) || | 
|             // Enclosed Ideographic Supplement | 
|             (0x1f200 <= x && x <= 0x1f251) || | 
|             // CJK Unified Ideographs Extension B .. Tertiary Ideographic Plane | 
|             (0x20000 <= x && x <= 0x3fffd) | 
|         ) | 
|     ) { | 
|         return true; | 
|     } | 
|   | 
|     return false; | 
| }; |