Hi, is it technically possible to resume continuat...

# coroutines

[Antanas A.]

Hi, is it technically possible to resume continuation twice when calling suspendCoroutine { cont -> cont.resumeWith(...) }?

[Dominaezzz]

No! It must only be done once. The second time would throw an exception I think. Do you need this?

[Antanas A.]

I am just thinking what capabilities would emerge if multiple returns would be possible. It will work as some kind of re-entrant call of function (which is parent program), it's hard to imagine mentally, but if it's possible maybe we could create something like Jetpack Compose without compiler addons.

[Dico]

Definitely not supported and dangerous

[Antanas A.]

why it would be dangerous?

[Antanas A.]

By reading some examples where CPS could be applied there are interesting cases: as backtracking or others:

[Antanas A.]

http://www.it.uu.se/edu/course/homepage/avfunpro/ht10/notes/html/f06-cont.html

[streetsofboston]

Use Flow for multiple value emissions.

If you're thinking about for-comprehension like or do-notation like functionality, the folks from Arrow actually did make a form of multi-shot continuation possible. Not sure if their current Fx library still does that or now uses a different approach.

[Dico]

Not considering Arrow, coroutine code abstracted by continuation contains a state machine based on your code, which is predicated on running exactly once. Therefore, if it runs more than once on the same state machine you get undefined behaviour.