RxJS でフィボナッチ数列

fib.ts

import { Observable, Subject } from 'rxjs';

const subj = new Subject();

subj.take(10).
  startWith([1, 1]).
  scan(([a, b], _) => [b, a + b]).
  do(([a, b]) => console.log(a)).
  subscribe();

while (true) { subj.next(); }