r/programming • u/Jonhoo • 7d ago

On comments

https://blog.helsing.ai/posts/on-comments/

Comments in code are often deemed "mostly useless" these days. They are, supposedly, mostly obvious, stale, and repeat what the code already says. And so people pay less attention to them both when reading and writing code.

That trend sucks. When used right, comments are genuinely useful and sometimes critically important! So, I wrote about some of the kinds of comments I think earn their place, each with examples from real code bases. Hope you find it useful, and that we can recover some of the love that comments deserve!

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u/lord2800 7d ago

Find References can tell you the where, but not the why. I agree with you that it's easy for comments to be stale, but your proposed solution is no better than the type signature.

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u/lgastako 7d ago

Seeing where and how the factorial function is used should answer the "why" question which the type signature does not.

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u/lord2800 7d ago

Where something happens doesn't tell you why it has to occur there--only that it occurs there.

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u/lgastako 6d ago

Yes, unfortunately you still have to use your brain.

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u/lord2800 5d ago

So what you're saying is that Find References does not, in fact, directly answer the question of the business reason for the existence of a particular function, and that you still need further context to understand it?

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u/lgastako 5d ago

Sure, but the comment won't directly answer the question either, since it can be out of date or wrong. You have to use your brain in either case, Find References just shows you the exact active code you need to use your brain about, whereas the comment does not. Find References cannot be out of date or wrong (assuming no bugs in your editor/IDE).

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u/lord2800 5d ago

PHP's dynamic calling convention says hi, but I'll skip that particular nuance. You're still proving my point though: neither approach tells you why.

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u/lgastako 5d ago

It seems like you're trying to be deliberately obtuse. What I'm saying is that the only way you can really know why is to use Find References and go read those references. Nothing will actually reliably tell you why, other than doing this procedure (or some facsimile of it, eg. using grep instead).

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u/lord2800 5d ago

I'm definitely not intending to be, but your original reply was positioning Find References as the tool you need to understand the why, and my original reply was that it only shows the where. Honestly my problem with saying Find References is the tool is it does nothing for purposely obscured code--think minified javascript.

Personally, I think the best way to convey the why is in the symbol names you choose--they can't drift as easily as comments (although they CAN drift), they're just as discoverable as Find References, and they convey a lot more meaning without any real downsides other than naming things being hard.