25 lines
713 B
JavaScript
25 lines
713 B
JavaScript
'use strict';
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var GetIntrinsic = require('get-intrinsic');
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var $TypeError = GetIntrinsic('%TypeError%');
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var $fromCharCode = GetIntrinsic('%String.fromCharCode%');
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var floor = require('./floor');
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var modulo = require('./modulo');
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var isCodePoint = require('../helpers/isCodePoint');
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// https://ecma-international.org/ecma-262/12.0/#sec-utf16encoding
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module.exports = function UTF16EncodeCodePoint(cp) {
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if (!isCodePoint(cp)) {
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throw new $TypeError('Assertion failed: `cp` must be >= 0 and <= 0x10FFFF');
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}
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if (cp <= 65535) {
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return $fromCharCode(cp);
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}
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var cu1 = $fromCharCode(floor((cp - 65536) / 1024) + 0xD800);
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var cu2 = $fromCharCode(modulo(cp - 65536, 1024) + 0xDC00);
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return cu1 + cu2;
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};
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