scan

example(of: "scan") { var dailyGainLoss: Int { .random(in: -10...10) } let august2019 = (0..<22) .map { _ in dailyGainLoss } .publisher august2019 .scan(50) { latest, current in max(0, latest + current) } .sink(receiveValue: { _ in }) .store(in: &subscriptions) }