22 lines
821 B
JavaScript
22 lines
821 B
JavaScript
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'use strict';
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var GetIntrinsic = require('get-intrinsic');
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var $TypeError = require('es-errors/type');
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var $fromCharCode = GetIntrinsic('%String.fromCharCode%');
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// https://262.ecma-international.org/7.0/#sec-utf16decode
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var isLeadingSurrogate = require('../helpers/isLeadingSurrogate');
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var isTrailingSurrogate = require('../helpers/isTrailingSurrogate');
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// https://262.ecma-international.org/11.0/#sec-utf16decodesurrogatepair
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module.exports = function UTF16Decode(lead, trail) {
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if (!isLeadingSurrogate(lead) || !isTrailingSurrogate(trail)) {
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throw new $TypeError('Assertion failed: `lead` must be a leading surrogate char code, and `trail` must be a trailing surrogate char code');
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}
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// var cp = (lead - 0xD800) * 0x400 + (trail - 0xDC00) + 0x10000;
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return $fromCharCode(lead) + $fromCharCode(trail);
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};
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