Comment by bottd
9 days ago
> If there is a need to comment the code all over the place, to me it means that the code is maybe not as good as it should be :-)
If good code was enough on its own we would read the source instead of documentation. I believe part of good software is good documentation. The prose of literate source is aimed at documentation, not line-level comments about implementation.
> If good code was enough on its own we would read the source instead of documentation.
That's 100% how I work -- reading the source. If the code is confusing, the code needs to be fixed.
Confusing code is one thing, but projects with more complex requirements or edge cases benefit from additional comments and documentation. Not everything is easily inferred from code or can be easily found in a large codebase. You can also describe e.g. chosen tradeoffs.
There's no way around just learning the codebase. I have never seen code documentation that was complete or correct, let alone both.
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Exactly, that's why a good project will use comments sparingly and have them only where they matter to actually meaningfully augment the code. The rest is noise.
Code alone can never describe intent or rationale.
Indeed, you need both!
But documentation should not go too deep in the "how" otherwise it risks telling a lie after a while as the code changes but the documentation lags.
https://diataxis.fr/
(originally developed at: https://docs.divio.com/documentation-system/) --- divides documentation along two axes:
- Action (Practical) vs. Cognition (Theoretical)
- Acquisition (Studying) vs. Application (Working)
which for my current project has resulted in:
- readme.md --- (Overview) Explanation (understanding-oriented)
- Templates (small source snippets) --- Tutorials (learning-oriented)
- Literate Source (pdf) --- How-to Guides (problem-oriented)
- Index (of the above pdf) --- Reference (information-oriented)
I've been trying to implement this as closely as possible from scratch in an existing FOSS project:
https://github.com/super-productivity/super-productivity/wik...
Even with a well-described framework it is still hard to maintain proper boundaries and there is always a temptation to mix things together.
I'm very near the idea that "LLM's are randomized compilers" and the human prompts should be 1000% more treated with care. Don't (necessarily) git commit the whole megabytes of token-blathering from the LLM, but keeping the human prompts:
"Hey, we're going to work on Feature X... now some test cases... I've done more testing and Z is not covered... ok, now we'll extend to cover Case Y..."
Let me hover over the 50-100 character commit message and then see the raw discussion (source) that led to the AI-generated (compiled) code. Allow AI.next to review the discussion/response/diff/tests and see if it can expose any flaws with the benefit of hindsight!
> If good code was enough on its own we would read the source instead of documentation.
An axiom I have long held regarding documenting code is:
An important addendum: code can sometimes, with a bit of extra thinking of part of the reader, answer the 'why' question. But it's even harder for code to answer the 'why not' question. Ie what were other approaches that we tried and that didn't work? Or what business requirements preclude these other approaches.
> But it's even harder for code to answer the 'why not' question.
Great point. Well-placed documentation as to why an approach was not taken can be quite valuable.
For example, documenting that domain events are persisted in the same DB transaction as changes to corresponding entities and then picked up by a different workflow instead of being sent immediately after a commit.
I don't think this is enough to completely obsolete comments, but a good chunk of that information can be encoded in a VCS. It encodes all past approaches and also contains the reasoning and why not in annotation. You can also query this per line of your project.
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Good naming and good tests can get you 90% of the way to "why" too.
Agreed. Tests are documentation too. Tests are the "contract": "my code solves those issues. If you have to modify my tests, you have a different understanding than I had and should make sure it is what you want".
Having "grown up" on free software, I've always been quick to jump into code when documentation was dubious or lacking: there is only one canonical source of truth, and you need to be good at reading it.
Though I'd note two kinds of documentation: docs how software is built (seldom needed if you have good source code), and how it is operated. When it comes to the former, I jump into code even sooner as documentation rarely answers my questions.
Still, I do believe that literate programming is the best of both worlds, and I frequently lament the dead practice of doing "doctests" with Python (though I guess Jupyter notebooks are in a similar vein).
Usually, the automated tests are the best documentation you can have!
I do read the code instead of the documentation, whenever that is an option.
Interesting factiod. The number of times I've found the code to describe what the software does more accurately than the documentation: many.
The number of times I've found the documentation to describe what the software does more accurately than the code: never.
You seem to misunderstand the purpose of documentation.
It's not to be more accurate than the code itself. That would be absurd, and is by definition impossible, of course.
It's to save you time and clarify why's. Hopefully, reading the documentation is about 100x faster than reading the code. And explains what things are for, as opposed to just what they are.
Clearly.
Crazy thing.
Number of times reading the source saved time and clarified why: many.
Number of times reading the documentation saved time and clarified why: never.
Perhaps I've just been unlucky?
EDIT:
The hilarious part to me is that everyone can talk past each other all day (reading the documentation) or we can show each other examples of good/bad documentation or good/bad code (reading the code) and understand immediately.
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> If good code was enough on its own we would read the source instead of documentation.
Uh. We do. We, in fact, do this very thing. Lots of comments in code is a code smell. Yes, really.
If I see lots of comments in code, I'm gonna go looking for the intern who just put up their first PR.
> I believe part of good software is good documentation
It is not. Docs tell you how to use the software. If you need to know what it does, you read the code.
> Lots of comments in code is a code smell. Yes, really.
No, not really. It's actually a sign of devs who are helping future devs who will maintain and extend the code, so they can understand it faster. It's professionalism and respect.
> If I see lots of comments in code, I'm gonna go looking for the intern who just put up their first PR.
And I'm going to find them to say good job, keep it up! You're saving us time and money in the future.
> It's professionalism and respect.
If someone gives me code full of superfluous comments, I don't consider it professional. Sounds like an intern who felt the need to comment everything because ever single line seemed very complex to them.
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> If you need to know what it does, you read the code.
True.
But If you need to know why it does what its does, you read the comments. And often you need that knowledge if you are about to modify it.
Do you have an example of such knowledge that you need to get from the comments? I have been programming for 20 years, and I genuinely don't see that much code that is so complex that it needs comments.
Not that it doesn't exist; sometimes it's needed. But so rarely that I call it "comments", and not a whole discipline in itself that is apparently be called "literate programming". Literate programming sounds like "you need to comment pretty much everything because code is generally hard to understand". I disagree with that. Most code is trivial, though you may need to learn about the domain.
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Not for everything. For code you own, yes this is often the case. For the majority of the layers you still rely on documentation. Take the project you mention going straight to source, did you follow this thread all the way down through each compiler involved in building the project? Of course not.
My understanding is that "literate programming" doesn't say "you should document the public API". It says "you should document the implementation details, because code is hard to understand".
My opinion is that if whoever is interested in reading the implementation details cannot understand it, either the code is bad or they need to improve themselves. Most of the time at least. But I hear a lot of "I am very smart, so if I don't understand it without any effort, it means it's too complicated".