I mentioned, at the beginning of this chapter, that protocol-oriented programming is about so much more than just the protocol, and that it is a new way of not only writing applications, but also thinking about programming. In this section, we will examine the differences between our two designs in order to understand what that statement really means.

As developers, our primary goal is to always develop an application that works properly, but we should also be focused on writing clean and safe code. Clean code is code that is very easy to read and understand. It is important to write clean code because any code that we write will need to be maintained by someone, and that someone is usually the person who wrote it. There is nothing worse than looking back at the code you wrote and not being able...