50 lines
1.3 KiB
JavaScript
50 lines
1.3 KiB
JavaScript
import { SYMBOL_ITERATOR } from "./symbols.mjs";
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/* eslint-disable no-redeclare */
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// $FlowFixMe[name-already-bound]
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var arrayFrom = Array.from || function (obj, mapFn, thisArg) {
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if (obj == null) {
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throw new TypeError('Array.from requires an array-like object - not null or undefined');
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} // Is Iterable?
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var iteratorMethod = obj[SYMBOL_ITERATOR];
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if (typeof iteratorMethod === 'function') {
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var iterator = iteratorMethod.call(obj);
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var result = [];
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var step;
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for (var i = 0; !(step = iterator.next()).done; ++i) {
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result.push(mapFn.call(thisArg, step.value, i)); // Infinite Iterators could cause forEach to run forever.
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// After a very large number of iterations, produce an error.
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// istanbul ignore if (Too big to actually test)
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if (i > 9999999) {
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throw new TypeError('Near-infinite iteration.');
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}
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}
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return result;
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} // Is Array like?
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var length = obj.length;
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if (typeof length === 'number' && length >= 0 && length % 1 === 0) {
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var _result = [];
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for (var _i = 0; _i < length; ++_i) {
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if (Object.prototype.hasOwnProperty.call(obj, _i)) {
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_result.push(mapFn.call(thisArg, obj[_i], _i));
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}
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}
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return _result;
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}
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return [];
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};
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export default arrayFrom;
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