onTermination
A callback to invoke when canceling iteration of an asynchronous stream.
Declaration
var onTermination: (@Sendable (AsyncStream<Element>.Continuation.Termination) -> Void)? { get nonmutating set }Discussion
If an onTermination callback is set, using task cancellation to terminate iteration of an AsyncStream results in a call to this callback.
Canceling an active iteration invokes the onTermination callback first, then resumes by yielding nil. This means that you can perform needed cleanup in the cancellation handler. After reaching a terminal state as a result of cancellation, the AsyncStream sets the callback to nil.