kiwix-js-pwa/www/js/lib/arrayFromPolyfill.js

/**
 * Simple Array.from polyfill (with Set support) from https://stackoverflow.com/a/62682524/9727685
 */
(function () {

	function arrayFrom(arr, callbackFn, thisArg) {
		//if you need you can uncomment the following line
		//if(!arr || typeof arr == 'function')throw new Error('This function requires an array-like object - not null, undefined or a function');

		var arNew = [],
			k = [], // used for convert Set to an Array
			i = 0,
			v;

		//if you do not need a Set object support then
		//you can comment or delete the following if statement
		if (window.Set && arr instanceof Set) {
			//we use forEach from Set object
			arr.forEach(function (v) {
				k.push(v)
			});
			arr = k;
		}

		for (; i < (arr.length || arr.size); i++) {
			v = typeof arr[i] !== 'undefined' ? arr[i] : arr.get ? arr.get(i) : null;
			arNew[i] = callbackFn ?
			callbackFn.call(thisArg, v, i, arr) : v;
		}
		
		return arNew;
	}
	//You could also use it without the following line, but it is not recommended because native function is faster.
	Array.from = Array.from || arrayFrom; //We set it as polyfill
}());