I reask again:
I am using SwiftNIO and I faced a problem with protocols, that caused me searching a long time for the bug, because my app didn't work as expected. I try to abstract the problem with an example code:
Let's say, we have a protocol, that implements methods for handling values:
protocol HandlerProtocol {
func handleMethod(parameter1: String, parameter2: Int)
}
The framework, that implements this protocol, could look like this:
struct MyFramework {
var handler: HandlerProtocol?
// some other methods, doing very important stuff
// and of course one of them will call:
func handleMessages(parameter1: String, parameter2: Int) {
self.handler?.handleMethod(parameter1: parameter1, parameter2: parameter2)
}
}
Now let's assume, that the protocol has a lot more methods and while creating all theses methods, I came to the decision, that the user will not need all of those methods. So I will make some "default implementations" with an extension:
extension HandlerProtocol {
func handleMethod(parameter1: String, parameter2: Int) {
print("do sth. with \(parameter1) and \(parameter2)")
}
}
Now the problem starts, if I implement this protocol to a class but if I will make a typo like this ("param" insteand of "parameter"):
class DummyHandler: HandlerProtocol {
func handleMethod(param1: Float, param2: Int) {
// I'm never called by the handleMessages-method :( :(
}
}
In my opinion the compiler should check, if there are methods, that have the same name as those of the protocols and it should give a warning about that, that maybe the protocol isn't implemented correctly.
The other suggestion would be to make sth. like this (instead of an extension)?
implement protocol HandlerProtocol {
func handleMethod(parameter1: String, parameter2: Int) {
....
}
}
In this case, the compiler and everyone looking to the code would know, that there are default implementations (I am still confused about the way of extension, because to be honest, the code above gives methods with bodies to a protocol, but normally protocol methods doesn't allow bodies).
Xcode could then tell the user: "Hey, the protocol has default implementations! Do you want to implement one, two or all methods by yourself?"