[typescript] Should I use a promise to represent an event that can occur at most once, may never occur but can never fail? If not, what else should I use? Callbacks?

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    Well actually the event occurs several times but it doesn't really make sense to listen to multiple of them so I only have a function to catch the next one.
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    I'm using rxjs observables and unsubscribing upon invocation. It's a hack, a horrible one I must say, judging by how difficult it is to unsub, but it works. I wonder what others do tho.

    Edit: I'm not a js/ts dev 😁
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    Lacking background knowledge, how do you want to represent an event as a Promise ? There is basically no difference to use a promise or callbacks. It’s just syntactic sugar IMO.
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    @dder The difference is in semantics. Promises can reject anytime for any reason. If a callback has no "error" argument you know there's nothing to handle. At the same time, promises can only be resolved once, for a callback that isn't a given. However, one might assume that a promise will resolve or reject at some point, whereas in my case that can't be known.
    Additionally, with promises I have much less control over references so it's harder to let the user cancel the request and ensure that the handler gets GCd.
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    Oh, and Promises can be passed to Promise.all([...]) as opposed to callbacks.
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