async-await.swift

import Foundation
import Combine
import PlaygroundSupport

func await<T>(_ body: @escaping (@escaping (T) -> Void) -> AnyCancellable) -> T {
    return {
        var result: T! = nil
        let semaphore = DispatchSemaphore(value: 0)
        body { value in
            result = value
            semaphore.signal()
        }
        semaphore.wait()
        return result!
    }()
}
func async(_ body: @escaping () -> Void) {
    DispatchQueue(label: "async").async(execute: body)
}

async {
    let response1 = await(URLSession.shared.dataTaskPublisher(for: URL(string: "https://apple.com")!).assertNoFailure().sink)
    print(response1.data)
    let response2 = await(URLSession.shared.dataTaskPublisher(for: URL(string: "https://google.com")!).assertNoFailure().sink)
    print(response2.data)
}

PlaygroundPage.current.needsIndefiniteExecution = true