What's the purpose of the

Flow.cancellable

operator ? What kind of use case does it solve ?

I think it's for when you have a flow that is made completely out of non cancellable functions but you want it to be cancellable on element emission. Am I right @elizarov?

Right

https://gist.github.com/octylFractal/9cd8b2cd0c71c123d657acde8fef3d31 is a simple example

That example is ready to paste in the editor on kotl.in or play.kotlin for you to try @tseisel

I see, this checks for cancellation on each

emit

and propagate it when applicable, which is not performed otherwise for performance reasons. Does this apply for thread-blocking code as well ?

Thread.sleep

show a different behavior

no, unless you wrap it in

runInterruptible

-- cancellation must be picked up by checking

isActive

, which is impossible for anything that isn't depending on the coroutines library (this means that suspend functions defined in stdlib also are not cancellable)

@octylFractal Where does

runInterruptible

come from?

coroutines library? https://kotlin.github.io/kotlinx.coroutines/kotlinx-coroutines-core/kotlinx.coroutines/run-interruptible.html

Ah, I had to update kotllinx.coroutines in the project I'm working on (how ironic since it's a project to update libraries!), TIL this exists, great stuff for interop, thank you 👍