| '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; | |
| }; |