polyfills.js

// https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number/isInteger#Polyfill
// https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Math/log2#Polyfill
// https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/isArray#Polyfill
// https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/indexOf#Polyfill
Number.isInteger = Number.isInteger || function(value) {
	return typeof value === 'number' && 
		isFinite(value) && 
		Math.floor(value) === value;
};
Math.log2 = Math.log2 || function(x) {
	return Math.log(x) * Math.LOG2E;
};
Array.isArray = Array.isArray || function(arg) {
	return Object.prototype.toString.call(arg) === '[object Array]';
};
Array.prototype.indexOf = Array.prototype.indexOf || (function(Object, max, min){
	"use strict";
	return function indexOf(member, fromIndex) {
		if(this===null||this===undefined)throw TypeError("Array.prototype.indexOf called on null or undefined");
		
		var that = Object(this), Len = that.length >>> 0, i = min(fromIndex | 0, Len);
		if (i < 0) i = max(0, Len+i); else if (i >= Len) return -1;
		
		if(member===void 0){ for(; i !== Len; ++i) if(that[i]===void 0 && i in that) return i; // undefined
		}else if(member !== member){	 for(; i !== Len; ++i) if(that[i] !== that[i]) return i; // NaN
		}else for(; i !== Len; ++i) if(that[i] === member) return i; // all else

		return -1; // if the value was not found, then return -1
	};
})(Object, Math.max, Math.min);