Retrying on Subjects.

retry_on_subject.swift

import Combine

var subscriptions = Set<AnyCancellable>()

enum SomeError: Error { /// (1) inb4 rogue code review, this is for sake of example.
	case anError
}

let subject = PassthroughSubject<Int, SomeError>()

subject
	.retry(1) /// (2) The key bit.
	.sink(
		receiveCompletion: { print($0) },
		receiveValue: { print($0) }
	)
	.store(in: &subscriptions)

subject.send(1)
subject.send(2)
subject.send(3)

subject.send(completion: .failure(.anError))

subject.send(4)