Explaining Very Bad Storm Clojure Code
This afternoon I'm forced to stay late because two guys in the group needed to have some ver bad clojure code explained to them because the guy that wrote it was off for the day, and the code he wrote was bad - to say the least. First, to be fair, this is clojure code, so it can be tough for some to understand, but these two guys aren't bad, so I don't think that was the issue.
No, the issue is that you can read clojure code a lot sooner than you can write good clojure code. For example, this was in the most convoluted function:
(defn build-a-bridge [start-point end-point & [lanes type width]] (let [lanes (or lanes (/ width 20)) ... ))
in a few short lines, he'd done so many bad things - that actually would work - that it made understanding this code very hard for these two guys.
Start with the re-valuation:
(let [lanes (or lanes (/ width 20))
yes, it's possible, but in the real code, there was so much else going on it was hard to see this (the guys missed it), and so they thought that the lanes argument was nil, when in fact, it was being re-valued in the let. Yes, it's legal, but it's bad form, and the reason it was done is because the author really didn't understand optional arguments:
(defn build-a-bridge [start-point end-point & [lanes type width]]
Here, the type of the bridge is non-optional - and so, really, are the number of lanes. Yet he was in so much of a hurry to get this done in the day, that he slapped things wherever he needed to to get them to work. Then, when the optional args were nil, he used the re-valueing to "make them right".
To call it hacks is being generous. It was a horrible way to use functional code, and it was all because he wanted to impress. Impress management that he's capable of getting the feature out in a day. In truth, it should have been an hour, but a day for him was within reasonable limits. But the time slipped by, and he started to panic.
I think it's fair to say that a panicked rookie clojure developer is bound to make some pretty bad code. And so I had to stay late to explain this code to the others in the team that couldn't figure it out for themselves.
And I'm the one that has to leave... Insanity.