Convert `CoroutineContext` into `Executor`

I have to use an API that accepts an Executor as a parameter. How can I create an Executor that is backed by Dispatchers.Default?

Can a CoroutineDispatcher.asExecutor(): Executor function be added to support this use case?

fun externalApi(executor: Executor)

fun example() {
  val executor: Executor = Dispatchers.Default.asExecutor()
  
  externalApi(executor)
}

Even better would be a fun CoroutineContext.asExecutor(): Executor function. I would imagine if the receiver CoroutineContext does not have a ContinuationInterceptor, this function would throw.

[elizarov]

@ZakTaccardi You can write the following simple extension for your use-case:

fun CoroutineContext.asExecutor(): Exector = 
    (get(ContinuationInterceptor) as CoroutineDispatcher).asExecutor()

[ZakTaccardi]

@zach-klippenstein For my use case, it would be fine to throw if the CoroutineContext does not contain a CoroutineDispatcher. I do something like the following:

AppDispatchers(
  val main: CoroutineContext = Dispatchers.Main,
  val default: CoroutineContext = Dispatchers.Default,
  val io: CoroutineContext = Dispatchers.IO,
)

CoroutineContext is preferred over CoroutineDispatcher as a type because it allows us to do something like dispatchers.copy(default = default + CoroutineExceptionHandler { ..}) (basically just the Liskov Substituion Principle)