D-ASYNC CloudSharp is an extension to C# language that introduces new paradigms of service-oriented cloud programming. The new syntax removes the need to use or to create a framework for service APIs, inter-service communication, workflows, and state management.
The basic concepts define a serivce and its contract, most common communication primitives: query, command, event, event handler.
// A service API contract that is transpiled into an interface. service contract IUserService { query List<User> GetActiveUsers(); command void Register(string name, string email); command bool SuspendUser(string userId); event EventHandler<User> UserRegistered; }// A service implementation that is transpiled into a class. service UserService : IUserService { command void Register(string name, string email) { var user = new User(name, email); // ..... // Publish an event. publish UserRegistered(this, user); } }service RewardService { public RewardService(IUserService userService) { // Subscribe to an event of another service. subscribe OnUserRegistered to userService.UserRegistered; } // An event handler. handler OnUserRegistered(object sender, User user) { // ..... } }service OrderService { command ProcessOrder(Order order) { // The variable is saved as a part of the execution state. persisted Guid transactionId = Guid.NewGuid(); // Save execution state of this method when invoke the command. follow ProcessPayment(order, transactionId); try { follow ReserveItems(order); } catch (OutOfStockException) { // Use saved transaction ID to guarantee idempotency. follow CancelPayment(transactionId); throw; } follow ShipItems(order); } command ProcessPayment(Order order, Guid transactionId) { ..... } command CancelPayment(Guid transactionId) { ..... } command ReserveItems(Order order) { ..... } command ShipItems(Order order) { ..... } }The ability to describe higher level concepts using the syntax of a programming language itself produces at least 5 times less code, makes the program more readable, saves a lot of time to understand and maintain a multi-service application.