Depth-first programmers

Depth-first programmers are always busy creating horribly complicated solutions that are somehow off the mark. Here’s why and what to do against it.

Just as there are at least two fundamentally different approaches for searching, namely depth-first and breadth-first search, there are also different types of programmers. The depth-first programmer is a dangerous type, as he is prone to yak shaving and reinvention of the wheel.

The depth-first programmer

Let me try to define the term of a “depth-first programmer” by a little (true) story. A novice java programmer should make some changes to an existing code. To secure his work, he should and wanted to write unit tests in JUnit. He started the work and soon enough, first results could be seen. But when he started to write his tests, the progress notifications stopped. The programmer worked frantically for hours and then days to write what appeared to be some simple data-driven tests.

Finally, the novice java programmer reported success and showed his results. He wrote his tests and “had to extend JUnit a bit to do it right”. Wait, what? Well, in JUnit, the test methods cannot have parameters, but the programmer’s tests needed to be parametrized. So he replaced the part of JUnit that calls the test methods by reflection with an “improved” algorithm that could also inject parameters. His implementation relied on obscure data structures that provided the actual parameter values and only really worked for his needs. The whole mess was nearly intangible, a big bloat and needed most of the development time for the unit tests.

And it was totally unnecessary once you learn about “Parameterized” JUnit4 tests or build light-weight data drivers instead of changing the signature of the test method itself. But this programmer dove deep into JUnit to adjust the framework itself to his needs. When asked about it, he stated that “he needed to pass the parameters somehow”. That’s right, but he choose the most expensive way to do so.

He exhibited the general behaviour of a depth-first programmer: whenever you face a problem, take the first possible solution to a problem you can come up with and work on it without evaluation against other possibilities. And continue on the path without looking back, no matter how long it takes.

Stuck in activism

The problem with this approach should be common sense. The obvious option isn’t always the best or even a good one. You have to evaluate the different possible solutions by their advantages and drawbacks. A less obvious solution might be far better in every aspect but obviousness. Another problem with this approach is the absence of internal warning signs.

Getting stuck is an internal warning sign every programmer understands. You’ve worked your way in a certain direction and suddenly, you cannot advance further. Something blocks your anticipated way of solving the problem and you cannot think of an acceptable way past it. A depth-first programmer never gets stuck this way. No matter how expensive, he will pursue the first thing that brings him closer to the target. A depth-first programmer always churns out code at full speed. Most of it isn’t needed on second thought and can be plain harmful when left in the project. The depth-first programmer will always report progress even when he needs days for a task of minutes. He is stuck in activism.

Progress without guidance

This isn’t a rant about incompetent programmers. Every good programmer knows the situation when you suddenly realize that you’re shaving a yak when all you wanted to do is to add a feature to the code base. This is your self-guidance system regaining consciousness after a period of auto-piloting in depth-first mode. Every programmer behaves depth-first sometimes.

This can be explained with the Dreyfus Model of Skill Acquisition. On the first stage, called “Beginner”, you are simply not capable of proper self-evaluation. You cannot distinguish between good and not so good approaches beforehands or even afterwards. Your expertise in the narrow field of the problem at hand isn’t broad enough to recognize an error even when you are working on the error yourself for prolonged times.

In the Dreyfus Model, a beginner needs external guidance. Somebody with more experience has to point out errors for you and formulate alternatives as clearly and specific as possible. Without external guidance, a beginner will become a depth-first programmer. We’ve all been there.

 Be a guide

The real failure in the story above was done by me. Instead of interacting with the novice java programmer after a few hours when I thought he should be done by now, I let him “advance”. I could have avoided the resulting mess by providing guidance and a few alternate solutions for the immediate problem. I would give an overview of the problem’s context and some hints about the general direction this task should be solved.

Every depth-first programmer works in a suboptimal environment. The programmer tries his best, it’s really the environment that could do better.

So, the next time you see somebody working frantically on a problem that should be rather easy to solve, lend him a hand. Be gentle and empathic about his attempt and work with proposals, not with instructions. Perhaps you’ve spared yourself a mess like an unnecessarily extended JUnit library and the depth-first programmer the frustration when his hard work of several days is silently discarded.