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  1. {"ast":null,"code":"'use strict';\n\nvar ctx = require('./_ctx');\n\nvar $export = require('./_export');\n\nvar toObject = require('./_to-object');\n\nvar call = require('./_iter-call');\n\nvar isArrayIter = require('./_is-array-iter');\n\nvar toLength = require('./_to-length');\n\nvar createProperty = require('./_create-property');\n\nvar getIterFn = require('./core.get-iterator-method');\n\n$export($export.S + $export.F * !require('./_iter-detect')(function (iter) {\n Array.from(iter);\n}), 'Array', {\n // 22.1.2.1 Array.from(arrayLike, mapfn = undefined, thisArg = undefined)\n from: function from(arrayLike\n /* , mapfn = undefined, thisArg = undefined */\n ) {\n var O = toObject(arrayLike);\n var C = typeof this == 'function' ? this : Array;\n var aLen = arguments.length;\n var mapfn = aLen > 1 ? arguments[1] : undefined;\n var mapping = mapfn !== undefined;\n var index = 0;\n var iterFn = getIterFn(O);\n var length, result, step, iterator;\n if (mapping) mapfn = ctx(mapfn, aLen > 2 ? arguments[2] : undefined, 2); // if object isn't iterable or it's array with default iterator - use simple case\n\n if (iterFn != undefined && !(C == Array && isArrayIter(iterFn))) {\n for (iterator = iterFn.call(O), result = new C(); !(step = iterator.next()).done; index++) {\n createProperty(result, index, mapping ? call(iterator, mapfn, [step.value, index], true) : step.value);\n }\n } else {\n length = toLength(O.length);\n\n for (result = new C(length); length > index; index++) {\n createProperty(result, index, mapping ? mapfn(O[index], index) : O[index]);\n }\n }\n\n result.length = index;\n return result;\n }\n});","map":null,"metadata":{},"sourceType":"script"}