Chapter 7. Wallowing in Filth

As a dog returns to its vomit, so fools repeat their folly.

Psalms 26:11

We’ve all encountered it: quicksand code. You wade into it unawares, and pretty soon you get that sinking feeling. The code is dense, not malleable, and resists any effort made to move it. The more effort you put in, the deeper you get sucked in. It’s the man-trap of the digital age.

How does the effective programmer approach code that is, to be polite, not so great? What are our strategies for coping with crap?

Don’t panic, don your sand-proof trousers, and we’ll wade in…

Smell the Signs

Some code is great, like fine art, or well-crafted poetry. It has discernible structure, recognisable cadences, well-paced meter, and a coherence and beauty that make it enjoyable to read and a pleasure to work with.

But, sadly, that is not always the case.

Some code is messy and unstructured: a slalom of gotos that hide any semblance of algorithm. Some is hard to read: with poor layout and shabby naming. Some code is cursed with an unnecessarily rigid structure: nasty coupling and poor cohesion. Some code has poor factoring: entwining UI code with low-level logic. Some code is riddled with duplication: making the project larger and more complex than it need be, whilst harbouring the exact same bug many times over. Some code commits “OO abuse”: inheriting, for all the wrong reasons, tightly associating parts of code that have no real need to be bound. Some code sits like a pernicious cuckoo ...

Get Becoming a Better Programmer now with the O’Reilly learning platform.

O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.