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- /*! http://mths.be/fromcodepoint v0.2.1 by @mathias */
- if (!String.fromCodePoint) {
- (function() {
- var defineProperty = (function() {
- // IE 8 only supports `Object.defineProperty` on DOM elements
- try {
- var object = {};
- var $defineProperty = Object.defineProperty;
- var result = $defineProperty(object, object, object) && $defineProperty;
- } catch(error) {}
- return result;
- }());
- var stringFromCharCode = String.fromCharCode;
- var floor = Math.floor;
- var fromCodePoint = function(_) {
- var MAX_SIZE = 0x4000;
- var codeUnits = [];
- var highSurrogate;
- var lowSurrogate;
- var index = -1;
- var length = arguments.length;
- if (!length) {
- return '';
- }
- var result = '';
- while (++index < length) {
- var codePoint = Number(arguments[index]);
- if (
- !isFinite(codePoint) || // `NaN`, `+Infinity`, or `-Infinity`
- codePoint < 0 || // not a valid Unicode code point
- codePoint > 0x10FFFF || // not a valid Unicode code point
- floor(codePoint) != codePoint // not an integer
- ) {
- throw RangeError('Invalid code point: ' + codePoint);
- }
- if (codePoint <= 0xFFFF) { // BMP code point
- codeUnits.push(codePoint);
- } else { // Astral code point; split in surrogate halves
- // http://mathiasbynens.be/notes/javascript-encoding#surrogate-formulae
- codePoint -= 0x10000;
- highSurrogate = (codePoint >> 10) + 0xD800;
- lowSurrogate = (codePoint % 0x400) + 0xDC00;
- codeUnits.push(highSurrogate, lowSurrogate);
- }
- if (index + 1 == length || codeUnits.length > MAX_SIZE) {
- result += stringFromCharCode.apply(null, codeUnits);
- codeUnits.length = 0;
- }
- }
- return result;
- };
- if (defineProperty) {
- defineProperty(String, 'fromCodePoint', {
- 'value': fromCodePoint,
- 'configurable': true,
- 'writable': true
- });
- } else {
- String.fromCodePoint = fromCodePoint;
- }
- }());
- }
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