A share-based approach to Publisher.prefixInclusive.

shared_prefix_while_inclusive.swift

import CombineExt

extension Publisher {
	func prefixInclusive(while predicate: @escaping (Output) -> Bool) -> AnyPublisher<Output, Failure> {
		let shared = share(replay: 1)

		return shared
			.prefix(while: predicate)
			.append(shared.first { !predicate($0) }) // We miiight be able to use the non-predicate `first`
			// operator — instead of `first(where:)` — since `append` subscribes to the provided publisher
			// only after upstream completes, which in our case loads a `predicate`-failing value to
			// `shared`’s internal buffer. If you‘re a thread-safety wizard who can chime in here, please do!
			.eraseToAnyPublisher()
	}
}