I love code. Regardless of what happens with my life, I will always code. If, tomorrow, I found that I was suddenly very independently wealthy, I would still code.
This passion pushes me to improve. One of the most frustrating things is to need to rearchitect something for no good reason. So, I am always looking for ways to improve my code. I read books and blogs, and try to actively apply the things that I have learned in the code that I write. Typically, I love all the advice I have gotten from various sources over the years, and my code has improved dramatically.
There is something that has always bothered me about programming advice, though. This was a topic that I touched on in the second phase of learning to program. From my recollection, all advice on how to write good code follows the same general principles. A model object might do too much, and thus need to be split apart. A controller might be doing something "more" than simply coordinating the models and the views, and needs to have that logic removed. A function might just get too large, and should then be split apart. A database might have a denormalized schema, which makes updating difficult, and thus should be normalized.
These guidelines feel really similar to one another. This is good, because it probably means they make sense. It would be suspicious if we were getting wildly different advice from different sources. However, this also suggests existence of an underlying, unifying principle. Does such a principle exist?
Personally, I am not sure. But, I do have an idea about what it might be. I have been thinking that programming is fundamentally about the "idea", and the act of programming is just the act of codifying ideas.
Lets talk about what this means. Really abstract things are hard. For these purposes, I mean an idea is a mental state -- something that can be held in your brain. These states, these basic units of information, are the stuff that our existence is made out of. Just as there is a limit to how much we can consider at a moment, there is also a limit to the size and complexity of an idea.
Regardless of the form that our code takes, we somehow force it our heads around it. Imagine examining a method that is not trivial to grasp. We would probably decomposing it, possibly by creating a story about its behavior. First it "does this", then it "does that". In any case, this method is now composed of multiple ideas, even though it is still one method. Our program does not match the structure of our thoughts, and this creates a hefty brain tax.
Once we realize this, we can alleviate this pressure by changing the structure of our code. We could do something as simple as splitting this method into multiple methods, or we could create a service object. Either way, we have just brought the code into line with the way we think about it.
I have started to try to develop a process for applying this principle, with the goal of trying to get a sense of whether or not it works. So far, results the are fruitful. Focusing on the ideas that need to be expressed has drastically helped me every time I have applied it.
So, what have we (maybe) gained? We have a framework to understand how all of this design advice fits together, as well as a metric to help us think about how to apply it. We also have a general principle to help us decide how our code should be structured. I think that's a win, either way. Let me know your thoughts!