@swift-main -Xfrontend -emit-sil -Xfrontend -enable-experimental-concurrency

import Foundation func download(from url: URL) async throws -> Data { fatalError("Unimplemented yet.") } let url: URL! = nil @asyncHandler func onButtonPressed(_ sender: Any) { do { let data = try await download(from: url) print(data.count) } catch { print("\(error)") } }