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Comment by christophilus | Hacker News Reader

After 20 years as a software engineer, I've started commenting heavily. I used to comment sparingly. What made me change was a combination of reading the SQLite and Redis codebases and inheriting two biggish projects (one Rails, and one JS) which had no comments.

Reading through code that looks like this[0] is so much nicer than reading through code that looks like this[1].

[0] https://www.sqlite.org/src/artifact/9711a7575036f0d3

[1] https://github.com/mysql/mysql-server/blob/b93c1661d689c8b7d...

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I made an opposite journey. While working in C and Java I commented heavily, but in Python I prefer to just leave a comment here and there if I'm not sure the reason for the code and its intent are clear - but at the same time a comment is also a powerful signal for me to rethink that piece of code and make it more obvious.

I find both of your examples readable to about the same level; MySQL one because the naming is helpful (`number_of_bytes_read_from_buffer`) and SQLite one because of the comments - I would be lost without them. For example, why is a function that does "Release the STATIC_MASTER mutex" called "leaveMutex"? On the other hand, SQLite comments explain much more about how the code is used, what assumptions are made, so this is really a bonus.

The problem is there's not just one type of code. Shared low-level code needs much more comments as shuffling a bunch of words through memory often is a bit abstract and you don't get the "why" by just looking at it, while writing business code that basically glues the UI to the DB using a lot of frameworks for the ugly parts can (and should) read like English.

I would suggest to use commenting as soon as you're doing something that's not immediately obvious to the reader, which can be all of the time or almost never depending on what you're doing. If would like to see some examples of Rails or JS code that needs comments according to you to have a better discussion about it.

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