/**

• tallbag-from-obs

• ---

• Convert an observable (or subscribable) to a tallbag listenable source.
• npm install tallbag-from-obs
• Example:
• Convert an RxJS Observable:

• const Rx = require('rxjs');

• const fromObs = require('tallbag-from-obs');

• const observe = require('callbag-observe');

• const source = fromObs(Rx.Observable.interval(1000).take(4));

• observe(x => console.log(x)(source); // 0

•                                      // 1

•                                      // 2

•                                      // 3

• Convert anything that has the .subscribe method:

• const fromObs = require('tallbag-from-obs');

• const observe = require('callbag-observe');

• const subscribable = {

•   subscribe: (observer) => {

•     let i = 0;

•     setInterval(() => observer.next(i++), 1000);

•   }

• };

• const source = fromObs(subscribable);

• observe(x => console.log(x))(source); // 0

•                                       // 1

•                                       // 2

•                                       // 3

•                                       // ...

*/

const makeShadow = require('shadow-callbag').default; const $$observable = require('symbol-observable').default;

const fromObs = observable => (start, sink) => { if (start !== 0) return; let dispose; const shadow = makeShadow('from-obs'); function talkback(t) { if (t === 2 && dispose) { if (dispose.unsubscribe) dispose.unsubscribe(); else dispose(); } } sink(0, talkback, shadow); observable = observable[$$observable] ? observable$$observable : observable; dispose = observable.subscribe({ next: x => { shadow(1, x); sink(1, x); }, error: e => sink(2, e), complete: () => sink(2), }); };

module.exports = fromObs;