| Leo Repp | 58b9f11 | 2021-11-22 11:57:47 +0100 | [diff] [blame^] | 1 | 'use strict'; |
| 2 | |
| 3 | var GetIntrinsic = require('get-intrinsic'); |
| 4 | |
| 5 | var $TypeError = GetIntrinsic('%TypeError%'); |
| 6 | var $fromCharCode = GetIntrinsic('%String.fromCharCode%'); |
| 7 | |
| 8 | var floor = require('./floor'); |
| 9 | var modulo = require('./modulo'); |
| 10 | |
| 11 | var isCodePoint = require('../helpers/isCodePoint'); |
| 12 | |
| 13 | // https://262.ecma-international.org/7.0/#sec-utf16encoding |
| 14 | |
| 15 | module.exports = function UTF16Encoding(cp) { |
| 16 | if (!isCodePoint(cp)) { |
| 17 | throw new $TypeError('Assertion failed: `cp` must be >= 0 and <= 0x10FFFF'); |
| 18 | } |
| 19 | if (cp <= 65535) { |
| 20 | return $fromCharCode(cp); |
| 21 | } |
| 22 | var cu1 = floor((cp - 65536) / 1024) + 0xD800; |
| 23 | var cu2 = modulo(cp - 65536, 1024) + 0xDC00; |
| 24 | return $fromCharCode(cu1) + $fromCharCode(cu2); |
| 25 | }; |