You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
 
 
 

25 lines
700 B

'use strict';
var GetIntrinsic = require('get-intrinsic');
var $TypeError = GetIntrinsic('%TypeError%');
var $fromCharCode = GetIntrinsic('%String.fromCharCode%');
var floor = require('./floor');
var modulo = require('./modulo');
var isCodePoint = require('../helpers/isCodePoint');
// https://262.ecma-international.org/7.0/#sec-utf16encoding
module.exports = function UTF16Encoding(cp) {
if (!isCodePoint(cp)) {
throw new $TypeError('Assertion failed: `cp` must be >= 0 and <= 0x10FFFF');
}
if (cp <= 65535) {
return $fromCharCode(cp);
}
var cu1 = floor((cp - 65536) / 1024) + 0xD800;
var cu2 = modulo(cp - 65536, 1024) + 0xDC00;
return $fromCharCode(cu1) + $fromCharCode(cu2);
};