IdentifiableContinuation is a lightweight wrapper around CheckedContinuation that conforms to Identifiable and includes an easy to use cancellation handler with the id.
IdentifiableContinuation can be installed by using Swift Package Manager.
Note: IdentifiableContinuation requires Swift 5.7 on Xcode 14+. It runs on iOS 13+, tvOS 13+, macOS 10.15+, Linux and Windows.
To install using Swift Package Manager, add this to the dependencies: section in your Package.swift file:
.package(url: "https://github.com/swhitty/IdentifiableContinuation.git", .upToNextMajor(from: "0.1.0"))Usage is similar to existing continuations, but requires an Actor to ensure the closure is executed within the actors isolation:
let val: String = await withIdentifiableContinuation(isolation: self) {
$0.resume(returning: "bar")
}This allows actors to synchronously start continuations and mutate their isolated state before suspension occurs. The onCancel: handler is @Sendable and can be called at any time after the body has completed. Manually check Task.isCancelled before creating the continuation to prevent performing unrequired work.
let val: String = await withIdentifiableContinuation(isolation: self) {
// executed within actor isolation so can immediatley mutate actor state
continuations[$0.id] = $0
} onCancel: { id in
// @Sendable closure executed outside of actor isolation requires `await` to mutate actor state
Task { await self.cancelContinuation(with: id) }
}IdentifiableContinuation is primarily the work of Simon Whitty.