gistfile1.txt

struct Counter: AsyncSequence {
    typealias Element = Int
    let howHigh: Int

    struct AsyncIterator: AsyncIteratorProtocol {
        let howHigh: Int
        var current = 1

        mutating func next() async -> Int? {
            guard current <= howHigh else {
                return nil
            }

            let result = current
            current += 1
            return result
        }
    }


    func makeAsyncIterator() -> AsyncIterator {
        return AsyncIterator(howHigh: howHigh)
    }
}