In this post I would like to look at the The Law of Useful Return. The Law of Useful Return says: If you have already done the work to get some useful result, don’t throw it away. Return it to the caller because they may be able to use it.
In this post we will look at the iterative approach to programming where we should be constantly looking to improve our code. Keep in mind that no one writes good code the first time' it takes many iterations to find the most efficient or general way to do something. No programmer should have a single pass mindset.
POP vs OOP
Numerous tutorials that I have seen take a very Object-Oriented approach to the protocol-oriented programming (POP) paradigm. By this statement I mean that they tell us that with POP we should begin our design with the protocol rather than with the superclass as we did with OOP however the protocol design tends to mirror the superclass design of OOP. They also tell us that we should use extensions to add common functionality to types that conform to a protocol as we did with superclasses in OOP. While protocols and protocol extensions are arguably two of the most important concepts of POP these tutorials seem to be missing some other very important concepts.
In this post I would like to compare Protocol-Oriented design to Object-Oriented design to highlight some of the conceptual differences.