Because I've already rewritten more of the standard library than is healthy.
I mean, it's clearly the right thing to do here but I can predict the conversation that will inevitably result... "You wrote your own tolower() function? Why?" "The standard one is horribly broken." "How could a function that lower-cases a letter be broken??? Jesus Kenton your NIH syndrome is out of control." "Sigh..."
(Slightly more seriously, any particular time I need to lower-case something, it takes 10 seconds to write out the code, but would take 10 minutes to find a good place to define a reusable function and exactly what its API should be, and so it never seems worth the effort in the moment. Just like how most messy code comes to be.)
This conversation can be simply be avoided by copy pasting your original hacker news comment into the library function header.
I have noticed some coworkers have their ego gratified by being right while everyone else is wrong. Instead of simply explaining what they are doing when they are doing it, they will do something that looks wrong in a very noticeable way and wait for the backlash. The backlash gives them an opportunity to show everyone else how they were right while everyone else was wrong and also an opportunity to play victim. However, in SW development - it is not just the technical details - your behavior also matters in a big way.
In this particular case, the correct approach is to create your own library function with appropriate comments. This is why the concept of a library function was invented. It is its entire raison-d'etre. However, you are doing everything but that. Including providing justifications in hacker news comments instead of your source code.
Now inevitably, someone will change your inline code to use to_lower. This will give you an opportunity to scream bloody murder, show how other engineers don't really understand technical details, correct them and also play victim. Create a library utility with comments and link it in - End of story.
I’m reminded of garbage collector blog posts where they do something stupid (“disable it”, “allocate a ballast”) and then get to spend a couple pages explaining why it worked for them.
Looks like you're only 10 times away from using this to having spent your 10 minutes ;)
But seriously, I'm not here to lecture you, but personally I'd appreciate having a teammate educate me on the undesired behavior and have a nice function I could use to ensure my own code doesn't break user input
Most codebases I've worked with have a StringUtils.java, or .kt, or a str.c or utils.c. Maybe just start one. Interestingly I haven't needed it as much in Ruby.
But I too feel the cognitive (and social!) burden of introducing a new function. It's not just "where do I put this", but "how do I convince the team I know what I'm doing since 15 years of experience clearly isn't enough and developers (mostly rightly) ignore positional authority and seniority".
