5 ms·

This is more or less what RxJS calls an Observable (except with nicer syntax). Here's a very nice table that makes the lack of this feature in ESnext seem like

• CGamesPlay 8y ago
  In case that link is your site, the SSL hostname is for `www.` not for the main domain, so it doesn't load in Safari. Chrome for whatever reason didn't care.
  • abraham 8y ago
    Chrome shows an interesting notice in the console. > Redirecting navigation danreynolds.ca -> www.danreynolds.ca because the server presented a certificate valid for www.danreynolds.ca but not for danreynolds.ca. To disable such redirects launch Chrome with the following flag: --disable-features=SSLCommonNameMismatchHandling
    • ThJ 8y ago
      It's not my site. Just didn't bother to hunt for that image in the RxJS docs and looked for it on GIS instead, since I was on a phone.
• tzahola 8y ago
  >Wouldn't it be wonderful if ESnext allowed you to write event loops that maintain state with block scope variables instead of all the hacks we have to resort to now? I think this is already possible: let event = null while (event = await getNextEvent()) { ... // process event } getNextEvent() creates a promise, registers an event handler which resolves it and returns the promise. Have I misunderstood your question?
  • ThJ 8y ago
    Suppose the events in question are network messages arriving via DOM callback. You call getNextEvent() and then what? You're not inside the event callback, so there's no event to hand back. You could push events onto an array as they arrive in the event callback and pop them off from getNextEvent(), but how? You can't await an array. Iterators won't help you either, because they are for pulling multiple results out of a function synchronously, not having multiple results pushed to the caller asynchronously. That's what asynchronous iterators / generators are for. Think of it like looping through an array, except the loop will halt to wait for elements that aren't populated yet.
    • ThJ 8y ago
      Now, on top of that, add the ability to run map(), reduxe() and filter() on a series of events. Instead of having to wait for all the elements in an array to be available, you can process it as you're receiving it, yet treat it as an already complete array in terms of being able to filter and transform it. It's a very powerful concept and I suggest you read about Observables in the RXJS docs. It took a while before it clicked for me.
      • jack9 8y ago
        > run map(), reduxe() and filter() on a series of events. Can't you do that with a btree already?
    • tzahola 8y ago
      Yeah... Well, I'm pretty sure you're wrong: 'use strict'; function getNextEvent() { return new Promise(resolve => { document.getElementById('button').onclick = event => resolve(event); }) } async function enterEventLoop() { let event = null; while (event = await getNextEvent()) { alert(event); } } enterEventLoop(); And thanks for recommending RxJS, but I've been using reactive programming on various platforms for the past 6 years, so I'm pretty sure it already had "clicked" for me.
• WorldMaker 8y ago
  Yes, there is a relationship, with RxJS on the "push" side and async iterators on the "pull" side. An interesting alternative to the library mentioned here is that IxJS is the RxJS team's own implementation of the sorts of operators that Axax is trying to provide, though for both ordinary iterators and async iterators: https://github.com/ReactiveX/IxJS https://github.com/ReactiveX/IxJS IxJS gets the benefits of trying to share as much as possible the same API as RxJS, making it really easy to use bits of IxJS and RxJS in the same project, depending on use case.