This Code is Crap, it Needs Rewritten

A few weeks ago I stumbled on Peter Naur’s essay Programming As Theory Building and it helped clarify a lot of things that have been on my mind for a while. It will likely be the source of many posts on this blog as time goes on, but there was one big idea that I’ve been obsessed with after reading it:

Not only are you building a theory of a program as you are programming, but you’re also building a theory of building programs.

It turns out that Naur even touches on this idea in Pluralism In Software Engineering (p79):


“For me, program development is all about grasping the relationship between:

* the modellee (the real-world problem),
* the model (the program),
* the model building elements (the programming language constructs).”

I’m still figuring out all the implications of this and working out how usable of a thought it is for my career, but it does explain some of the things I’ve seen so far. One in particular is the topic of this post.

I’m sure we’ve all seen people join a team we’ve been on for a long time and immediately decide the program is crap and that it needs to be rewritten. I’m also sure that we’ve been that person many times as well. While there is a chance that it actually is crap, there’s even more of a chance that there is a mismatch in theories. There’s almost definitely a mismatch in the new programmer’s theory of how to solve the particular problem this program solves and the way the original programmers who have been working on the program since the beginning solved the problem. But, and this is the big thing, it is also just as likely that there is a mismatch in their different theories of building programs.

You can see this manifest itself in a bunch of different ways such as basic style differences, usage of different language idioms, usage of different programming patterns, and where the new person is on the software political axis versus the team who built the program. Unless you’re really lucky, you’re likely to have some significant differences in ways you program to solve problems – enough that you’ll run into something frustrating that someone else did before you.

The best use of this insight that I can think of is to come at all projects with an open mind – though in a different way than you probably think. You want to try as hard as possible to lose your attachment to the ways you have solved problems in the past no matter how much better you think they are. On one hand, you could get to more viscerally feel the cons of using a certain pattern or idiom – but on the other hand, you could also be learning something useful you’ll take with you the rest of your career. Either way, though, your goal on a new team isn’t to prove how smart you are. Your goal should be to minimize the amount of time it takes you to internalize the theory of the program you’re working on and the team’s theory of building programs. Being frustrated with the way the team works together and complaining about how bad the program is will just make that it take longer. I’m not saying that if things really are bad that you just have to live with them, but you should be as comfortable in the program and with the theory of the program as the best on the team before you start suggesting changes that deviate far from current styles. The upside is that once you’ve internalized the new style, you should be able to incorporate and easily switch between any of the styles you’ve learned so far. So while you may need to keep your ego in check at first and treat a new style with a beginner’s mind, in the long run it will make you a much better programmer.