23 lines
413 B
JavaScript
23 lines
413 B
JavaScript
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'use strict';
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module.exports = (iterable, reducer, initVal) => new Promise((resolve, reject) => {
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const iterator = iterable[Symbol.iterator]();
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let i = 0;
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const next = total => {
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const el = iterator.next();
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if (el.done) {
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resolve(total);
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return;
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}
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Promise.all([total, el.value])
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.then(value => {
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next(reducer(value[0], value[1], i++));
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})
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.catch(reject);
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};
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next(initVal);
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});
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