Introduction
@Awaiting is a Swift @propertyWrapper
that waits asynchronously until the value matches a predicate.
Usage
Any class can declare a property to be @Awaiting
as follows:
@Awaiting var isComplete: Bool = false
You then use its projected value to await until some predicate is met;
// Suspends until isComplete == true
_ = try await $isComplete.first(where: { $0 })
Cancellation
CancellationError
is thrown if the task is cancelled before the predicate is met.
Optionals
When optionals are wrapped you can wait for the first non nil value:
@Awaiting var name: String?
// Suspends until name != nil
let name = try await $name.first()
Collections
When collections are wrapped you can wait for at least n elements to exist:
@Awaiting var names = [String]()
// Suspends until names.count >= 1
let nonEmpty = try await $names.first(withAtLeast: 1)
Credits
@Awaiting
is primarily the work of Simon Whitty.