ArrayConstructor.js [plain text]
function of()
{
"use strict";
var length = arguments.length;
var array = @isConstructor(this) ? new this(length) : new @Array(length);
for (var k = 0; k < length; ++k)
@putByValDirect(array, k, arguments[k]);
array.length = length;
return array;
}
function from(items )
{
"use strict";
var thisObj = this;
var mapFn = arguments.length > 1 ? arguments[1] : @undefined;
var thisArg;
if (mapFn !== @undefined) {
if (typeof mapFn !== "function")
throw new @TypeError("Array.from requires that the second argument, when provided, be a function");
if (arguments.length > 2)
thisArg = arguments[2];
}
if (items == null)
throw new @TypeError("Array.from requires an array-like object - not null or undefined");
var iteratorMethod = items.@iteratorSymbol;
if (iteratorMethod != null) {
if (typeof iteratorMethod !== "function")
throw new @TypeError("Array.from requires that the property of the first argument, items[Symbol.iterator], when exists, be a function");
var result = @isConstructor(thisObj) ? new thisObj() : [];
var k = 0;
var iterator = iteratorMethod.@call(items);
var wrapper = {}
wrapper.@iteratorSymbol = function() { return iterator; };
for (var value of wrapper) {
if (mapFn)
@putByValDirect(result, k, thisArg === @undefined ? mapFn(value, k) : mapFn.@call(thisArg, value, k));
else
@putByValDirect(result, k, value);
k += 1;
}
result.length = k;
return result;
}
var arrayLike = @Object(items);
var arrayLikeLength = @toLength(arrayLike.length);
var result = @isConstructor(thisObj) ? new thisObj(arrayLikeLength) : new @Array(arrayLikeLength);
var k = 0;
while (k < arrayLikeLength) {
var value = arrayLike[k];
if (mapFn)
@putByValDirect(result, k, thisArg === @undefined ? mapFn(value, k) : mapFn.@call(thisArg, value, k));
else
@putByValDirect(result, k, value);
k += 1;
}
result.length = arrayLikeLength;
return result;
}