38 lines
1.0 KiB
JavaScript
38 lines
1.0 KiB
JavaScript
// Based on:
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// http://norbertlindenberg.com/2012/05/ecmascript-supplementary-characters/
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// and:
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// https://github.com/mathiasbynens/String.fromCodePoint/blob/master
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// /fromcodepoint.js
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"use strict";
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var floor = Math.floor, fromCharCode = String.fromCharCode;
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// eslint-disable-next-line no-unused-vars
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module.exports = function (codePoint1/*, …codePoints*/) {
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var chars = [], length = arguments.length, i, codePoint, result = "";
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for (i = 0; i < length; ++i) {
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codePoint = Number(arguments[i]);
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if (
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!isFinite(codePoint) ||
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codePoint < 0 ||
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codePoint > 0x10ffff ||
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floor(codePoint) !== codePoint
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) {
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throw new RangeError("Invalid code point " + codePoint);
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}
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if (codePoint < 0x10000) {
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chars.push(codePoint);
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} else {
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codePoint -= 0x10000;
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// eslint-disable-next-line no-bitwise
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chars.push((codePoint >> 10) + 0xd800, (codePoint % 0x400) + 0xdc00);
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}
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if (i + 1 !== length && chars.length <= 0x4000) continue;
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result += fromCharCode.apply(null, chars);
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chars.length = 0;
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}
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return result;
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};
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