My first program in Apple Swift

first_program

// 1. Structure declaration
// 2. Enum declartion
// 3. Structure variables declaration
struct HTTPRequest {
    enum Method {
        case GET
        case POST
    }
    
    // Type Specific variable
    var path: String
    // Enumeration instance
    var method: Method
}


// 4. Abstract base class or virtual class
protocol HTTPHandlerType {
    // ** Not sure what it is.
    typealias Data
    
    func handle(request: HTTPRequest, data: Data) -> Bool
    
}

// 5. Class declaration
class HTTPServer {
    
    // 6. Abstract function signature, If you understand this line of code in first glance u r thru for generics.
    func addHandler<T: HTTPHandlerType>(handler: T) {
        
        // Populating values for an array. Absolutely cluess what is going on in the lines marked "holy shit"
        handlers.append {
            // HOLY SHIT
            (request: HTTPRequest, args: Any) -> Bool in
            
            // HOLY SHIT
            if let typedArgs = args as? T.Data {
                return handler.handle(request, data: typedArgs)
            }
            
            return false
        }
        
    }
    // 7. Array of tuple declaration I guess and initialization using []. Is it tuple, not quite sure. Is it array of function pointer
    private var handlers: [(HTTPRequest, Any) -> Bool] = []
    
    // 8. Function signature with Bool return type
    func dispatch(req: HTTPRequest, args: Any) -> Bool {
        
        for handler in handlers {
            // here it looks like function pointer
            if handler (req, args) {
                return true
            }
        }
        
        return false;
    }
    
}

// 9. Derived class
class MyHandler: HTTPHandlerType {
    // 10. Pure virtual(abstract) function implementation
    func handle(request: HTTPRequest, data: Int) -> Bool {
        return data > 5
    }
}

// 11. Object instance without new operator. Declare constants with let and variables with var
let server = HTTPServer()

server.addHandler(MyHandler())
server.dispatch(HTTPRequest(path: "/update", method: .POST), args: "x")

// 12. HIGHT OF MADNESS, UNICODE SUPPORT. People will declare variables in their local languages
let 你好 = "你好世界"
let சந்தோஷ் = "சந்தோஷ்"
var అజయ్ = "అజయ్"
var હાર્દિક = "હાર્દિક"