GAgabeidx·Sep 20, 2023
You may be thinking of the ECMAScript Observable proposal: https://github.com/tc39/proposal-observable
In Svelte 5: Runestc39
proposal-observable
JavaScript2015–2026
tc39 / proposal-observable
proposal-observable
Observables for ECMAScript
18Distinct people
20Mentions
0Explicit recommenders
3.1KGitHub stars
What to know before exploring
What it is
Observables for ECMAScript
GitHub
Where it is used
No documented product use was verified in the last source check.
What people are saying
No recommendation phrase was found in the indexed comments.
No classified warning is attached to this page. Read the discussions before treating silence as approval.
Also in these discussions
- reactive-extensions/rxjs · linked in 2 of the same discussions
Mentioned in the same Hacker News threads. That is not proof they are substitutes.
This week on Hacker News
Nov 8–Nov 15 UTC · Direct repository links and separately labeled related project stories. Indexed through 11/15/2026, 12:45:45 PM UTC.
No direct repository links were found in the indexed HN discussions over the past seven days. Older discussions are available below.
Mentions over time
HN mentions by year20 dated mentions
Observed mentions: 2015-08-23 02:02:14 UTC to 2026-04-07 20:28:34 UTC.
* An incomplete calendar period is marked with an outlined bar. Its count is not directly comparable with a full period.
Counts come from the repository’s dated source evidence. Index cutoff: 2026-11-02 08:16:59 UTC.
View mention counts and date ranges
| Period | Start (UTC) | End (exclusive, UTC) | Mentions | Submissions | Comments |
|---|---|---|---|---|---|
| 2015 | 2015-01-01 00:00:00 UTC | 2016-01-01 00:00:00 UTC | 4 | 1 | 3 |
| 2016 | 2016-01-01 00:00:00 UTC | 2017-01-01 00:00:00 UTC | 5 | 0 | 5 |
| 2017 | 2017-01-01 00:00:00 UTC | 2018-01-01 00:00:00 UTC | 2 | 0 | 2 |
| 2018 | 2018-01-01 00:00:00 UTC | 2019-01-01 00:00:00 UTC | 0 | 0 | 0 |
| 2019 | 2019-01-01 00:00:00 UTC | 2020-01-01 00:00:00 UTC | 1 | 0 | 1 |
| 2020 | 2020-01-01 00:00:00 UTC | 2021-01-01 00:00:00 UTC | 0 | 0 | 0 |
| 2021 | 2021-01-01 00:00:00 UTC | 2022-01-01 00:00:00 UTC | 1 | 0 | 1 |
| 2022 | 2022-01-01 00:00:00 UTC | 2023-01-01 00:00:00 UTC | 0 | 0 | 0 |
| 2023 | 2023-01-01 00:00:00 UTC | 2024-01-01 00:00:00 UTC | 4 | 0 | 4 |
| 2024 | 2024-01-01 00:00:00 UTC | 2025-01-01 00:00:00 UTC | 1 | 0 | 1 |
| 2025 | 2025-01-01 00:00:00 UTC | 2026-01-01 00:00:00 UTC | 0 | 0 | 0 |
| 2026 (partial) | 2026-01-01 00:00:00 UTC | 2027-01-01 00:00:00 UTC | 2 | 0 | 2 |
What Hacker News says
4 sourcesIt kind of had to get sent back to the drawing board to work well (avoid all the absurd one-at-a-time limitations of generators), but async-iteration-helpers I think will be an incidental huge help in normalizing/nudging the consumer api into "just an async iterable". Updating/writing state might be more complex, speak to the implementation, but seeing things change should have a semi-standard api.
https://github.com/tc39/proposal-async-iterator-helpers
One huge sadness I have is that when you have a callback in .then or .next, your handler doesn't get a gratis reference to what you were listening to. I'd love to have this be a better record. DOM is so good about having thick events that say what happened, and it's so helpful, sets such a rich base, but js snubbed that path & left passing data in 100% to each event producer to decide as i
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t will. Consumers can craft closures to seal some data into their handlers but it sucks compared to having an extensible data flow system. We're kind of sort of finally fixing this crime the hard way by standardizing async context/async_hooks, which is a whole new ambient way to create context that we can enrich our async events with, since there was no first class object to extend for having omitted passing in the promise to the promise handler. https://github.com/tc39/proposal-async-context
Also worth pointing out, maybe arguable as a hazard tale, observables was proposed a long long time ago. There's still a ton of adoption. But it also feels extremely similar yet notably apart & worse ergonomics than async iteration. It's imo a good thing it didn't get formalized. https://github.com/tc39/proposal-observable
Alas one reactivity I really wish we had had is object.observe (note: different API than observables), or something like it. Undoing good specification work & saying, 'yeah, if users want it, they can implement it themselves with proxies' has lead to no one doing it. And you can't just observe anything; whomever is the producer has to up front make the decision ahead of time for all consumers, which turned a great capability into something first boutique then quickly forgotten. Alas! https://esdiscuss.org/topic/an-update-on-object-observe
I ack your ask, and there's no shortage of options that are pretty damned good. But I feel like we are still in a discovery not deployment phase, still delay competing because we have a lot of terrain and idea space to consider. Before we pick, standardize & ship one.
How does it differ from <https://github.com/tc39/proposal-observable/>?
In Observable API ProposalI think it is a shame that the Observable proposal [1] still seems somewhat stuck in Stage 1. It's a better idea than just raw event emitters because of composability (if no other reason). Making Observables "first class" could go a long way to unifying a lot of reactivity patterns in various frameworks, in theory at least.
To be fair, Observables and especially Observable composition has a rough learning curve and many frameworks like Svelte intentionally prefer implict reactivity and avoiding things like explicit Observables because they are seen as too complex/"too hard" for the average developer.
(Then you get awful worst of both worlds frameworks like Angular that sort of rely on Observables but yet also don't trust teaching Observables and wind up with code that isn't properly Observable and so also has all the code for implicit rea
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ctivity and is full of nasty escape hatches that cause all sorts of composition problems and unnecessary side effects.)
[1] https://github.com/tc39/proposal-observable