24 lines
639 B
JavaScript
24 lines
639 B
JavaScript
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'use strict';
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var CodePointAt = require('./CodePointAt');
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var $TypeError = require('es-errors/type');
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// https://262.ecma-international.org/13.0/#sec-isstringwellformedunicode
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module.exports = function IsStringWellFormedUnicode(string) {
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if (typeof string !== 'string') {
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throw new $TypeError('Assertion failed: `string` must be a String');
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}
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var strLen = string.length; // step 1
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var k = 0; // step 2
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while (k !== strLen) { // step 3
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var cp = CodePointAt(string, k); // step 3.a
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if (cp['[[IsUnpairedSurrogate]]']) {
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return false; // step 3.b
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}
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k += cp['[[CodeUnitCount]]']; // step 3.c
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}
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return true; // step 4
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};
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