Functions

coroutineScope

,

withContext

,

withTimeout

and

supervisorScope

have very similar behavior and this group should have a name. In some places they are referenced as "Scoping functions", but I understand this can be confused with "Scope functions". What are your feelings about that? I am considering naming them "Coroutine scope function" or "Coroutine scoping functions".

Mmh I don't believe they have similar behaviour.

coroutineScope

and

supervisorScope

create a scope to allow launching coroutines, and suspend until those child coroutines terminate. These 2 could be grouped. The 2 others don't provide a scope, so they have quite different usage patterns and I don't quite get the need for a name that would encompass them as well.

withTimeout

is just a suspend function like any other, and I don't see it as related to

withContext

@Joffrey Show me, because as far as I tested, there is no difference between

coroutineScope

,

withContext(EmptyCoroutineContext)

and

withTimeout(Long.MAX_VALUE)

. They all create scope.

Apologies, then. I was answering from the top of my head, and

withTimeout

and

withContext

actually do provide a scope. That being said, they popped in such different contexts in my experience that I actually never had to consider these 4 as a group. And in particular, I never used

withTimeout

or

withContext

to actually start coroutines - just to control the timeout of some suspending code, or change the context. Starting a coroutine with

withContext

would be equivalent to just pass that context to the actual coroutine builder.

This is very interesting. I never would have thought

withTimeout

created a new scope. But I'm glad to see confirmation that

withContext

does create a new scope, rather than "just" modify context.

Yes, this is the current state of the chapter about both of them: https://kt.academy/article/cc-scoping-functions

Great! Just bought it!