44 lines
792 B
JavaScript
44 lines
792 B
JavaScript
const { ReplaySubject } = require('rxjs');
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const { map, scan } = require('rxjs/operators');
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const { exhaustMap, takeLast, take } = require('rxjs/operators');
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let _scan = scan((acc, curr) => {
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acc.push(curr);
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if (acc.length > 4) {
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acc.shift();
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}
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return acc;
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}, [])
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let _average = map(arr => arr.reduce((acc, current) => acc + current, 0) / arr.length)
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let sub = new ReplaySubject();
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sub.next(1)
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sub.next(2)
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sub.next(3)
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sub.next(4)
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// sub.pipe(_scan, _average).subscribe((v) => {
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sub.pipe(takeLast(2)).subscribe((v) => {
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console.log("got value " + v)
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})
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// result:
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// got value 1
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// got value 1.5
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// got value 2
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// got value 2.5
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// wanted result:
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// got value 2.5
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console.dir("---------")
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sub.next(5)
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sub.next(6)
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// expected afterwards
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// got value 3.5
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// got value 4.5
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