There need to be some first-class cancellation tok...

# coroutines

[elizarov]

There need to be some first-class cancellation token concept. The idea is that you can create a cancelllation token val myCancel = Cancellable(), then start a coroutine (or multiple coroutines) with this cancellation token via async(myCancel) {} or asycnGenerate(myCancel) {} or with any other coroutine builder that accepts a dispatcher as parameter and then you can cancel all of them with just myCancel.cancel(). Maybe it should be called Task or something. The idea is that you can have some high-level task that spawns multiple coroutines in the process, but if that task is cancelled, then you need to abort all the coroutines that are running in its context.