/* Polyfiller for Duktape for NetSurf * * This JavaScript will be loaded into heaps before the generics * * We only care for the side-effects of this, be careful. */ // Production steps of ECMA-262, Edition 6, 22.1.2.1 if (!Array.from) { Array.from = (function () { var toStr = Object.prototype.toString; var isCallable = function (fn) { return typeof fn === 'function' || toStr.call(fn) === '[object Function]'; }; var toInteger = function (value) { var number = Number(value); if (isNaN(number)) { return 0; } if (number === 0 || !isFinite(number)) { return number; } return (number > 0 ? 1 : -1) * Math.floor(Math.abs(number)); }; var maxSafeInteger = Math.pow(2, 53) - 1; var toLength = function (value) { var len = toInteger(value); return Math.min(Math.max(len, 0), maxSafeInteger); }; // The length property of the from method is 1. return function from(arrayLike/*, mapFn, thisArg */) { // 1. Let C be the this value. var C = this; // 2. Let items be ToObject(arrayLike). var items = Object(arrayLike); // 3. ReturnIfAbrupt(items). if (arrayLike == null) { throw new TypeError('Array.from requires an array-like object - not null or undefined'); } // 4. If mapfn is undefined, then let mapping be false. var mapFn = arguments.length > 1 ? arguments[1] : void undefined; var T; if (typeof mapFn !== 'undefined') { // 5. else // 5. a If IsCallable(mapfn) is false, throw a TypeError exception. if (!isCallable(mapFn)) { throw new TypeError('Array.from: when provided, the second argument must be a function'); } // 5. b. If thisArg was supplied, let T be thisArg; else let T be undefined. if (arguments.length > 2) { T = arguments[2]; } } // 10. Let lenValue be Get(items, "length"). // 11. Let len be ToLength(lenValue). var len = toLength(items.length); // 13. If IsConstructor(C) is true, then // 13. a. Let A be the result of calling the [[Construct]] internal method // of C with an argument list containing the single item len. // 14. a. Else, Let A be ArrayCreate(len). var A = isCallable(C) ? Object(new C(len)) : new Array(len); // 16. Let k be 0. var k = 0; // 17. Repeat, while k < len… (also steps a - h) var kValue; while (k < len) { kValue = items[k]; if (mapFn) { A[k] = typeof T === 'undefined' ? mapFn(kValue, k) : mapFn.call(T, kValue, k); } else { A[k] = kValue; } k += 1; } // 18. Let putStatus be Put(A, "length", len, true). A.length = len; // 20. Return A. return A; }; }()); }