🆕 Add a 'collect(until:)' operator

[ferologics]

Useful for collecting elements when there the element count is unknown or does not fit any time grouping strategy.

[freak4pc]

Hey @ferologics,
Thanks for the suggestion! I think it's a great idea but there are a few issues with the implementation.
Specifically, it is preferable that an operator doesn't use sink internally. Both because it's not a best practice, and because it automatically forces unlimited back pressure demand.

It seems to me it would be more appropriate to either:

1. Find a way to compose other operators to make this work; or
2. Build a custom publisher (similar to others in this repo) to be the consumer for the events and the trigger

[freak4pc]

Hey @ferologics, do you still want to pursue this operator?

[ferologics]

Hey @freak4pc, yes! Thank you for the thoughtful response. AFAIK this will require a custom publisher implementation. I will take a look at the implementation of other publishers in the repo and update the code accordingly 🙂

[ferologics]

@freak4pc I updated the PR with alternative implementation that avoids the sink on upstream. I haven't thought of a way to avoid the sink on trigger. Let me know if this is correct 🙌