In praise of repetitive code

Sep 13, 2014

It is well known that programmers should avoid repeating themselves. This is simply because when you need to change code, you would then need to update each of the repetitions, with an increasing chance of adding bugs with each change made. Thus, mnenomics like DRY or Don't Repeat Yourself.

However, what I often see is a reaction to that which goes too far in the opposite direction. I would call it premature optimization but it's not really performance that's at stake. It's more a premature unification of code, and it prevents finding the best way to organize the solution.

In my own practice, I strive for simplicity, clarity, and transparency. So when I am building something new or refactoring, I write code as simple and repetitive as possible. This benefits me in multiple ways:

  • I don't spend as much time worrying about the right way to do it, I just get it done.
  • The code is simpler because I am not aiming for any cleverness.
  • best of all, the patterns pop out at me by the repetition.

Afterwards, I can use the obvious patterns to fold the repetitions together into a single, non-repeating thing which handles all edge cases properly.

Contact me at renaissance.nomad (at) google.com