lepu-test-platform-web/node_modules/es5-ext/string/from-code-point/shim.js

38 lines
1.0 KiB
JavaScript

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