31 lines
1.1 KiB
JavaScript
31 lines
1.1 KiB
JavaScript
'use strict';
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var call = require('../internals/function-call');
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var isCallable = require('../internals/is-callable');
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var anObject = require('../internals/an-object');
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var getIteratorDirect = require('../internals/get-iterator-direct');
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var getIteratorMethod = require('../internals/get-iterator-method');
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var getMethod = require('../internals/get-method');
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var wellKnownSymbol = require('../internals/well-known-symbol');
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var AsyncFromSyncIterator = require('../internals/async-from-sync-iterator');
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var ASYNC_ITERATOR = wellKnownSymbol('asyncIterator');
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module.exports = function from(obj) {
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var object = anObject(obj);
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var alreadyAsync = true;
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var method = getMethod(object, ASYNC_ITERATOR);
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var iterator;
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if (!isCallable(method)) {
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method = getIteratorMethod(object);
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alreadyAsync = false;
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}
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if (method !== undefined) {
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iterator = call(method, object);
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} else {
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iterator = object;
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alreadyAsync = true;
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}
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anObject(iterator);
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return getIteratorDirect(alreadyAsync ? iterator : new AsyncFromSyncIterator(getIteratorDirect(iterator)));
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};
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