I'll happily be "so brave" and reiterate a simple truism of software development -- comments are the battle cry of terrible developers.
They are the crutch of people who can't read code: "Add more comments because otherwise I can't make sense of what the statements are doing." It is the English speaker demanding that every French passage have an English translation, rather than simply learning French.
They are the crutch of people who can't write code. "My code is a gigantic, illiterate mess, so instead read the comment at the top that has no guarantee of being robust or accurate."
Bringing up mathematicians and Knuth are both irrelevant distractions. Software development in the modern world is a very structure, self-describing affair, or at least it should be. Comments are the short-circuit from having to figure out how to do that.
I'm not meaning to insult you, but you sounds like a programmer who's experience consists solely of personal projects and academic assignments.
As has been said, comments explain why you are doing something in a certain way. That why is often related to a business process, several business process, and/or 25 different outside cases.
The code can be amazingly clean and organized, but you comment to indicate why you did something one way and not another.
I'd like you to offer some examples of code that successfully documents its own raison d'être - in a way that a comment couldn't do better - instead of repeating this 'crutch of poor developers' rhetoric.
I mean, I can write self documenting code without any comments, and it's perfectly understandable.
before_create :auto_increment
def auto_increment
self.count + 1
end
That code fails to tell the programmer why it's in the application logic and not defined in the database schema. What should I do instead, so I can code without crutches?
def auto_increment_natural_key
self.count + 1
end
That's not a great deal better, it's still just saying what it does, not why it's there in the first place.
def auto_increment_natural_key_because_another_app_relies_on_it
self.count + 1
end
Your code doesn't actually seem to do anything, so a comment would either be contradictory to the code, which is confusing, or explain why your code does nothing, which is silly.
I would argue that in this case, it is far better to just understand the code and then fix it appropriately. A comment would leave you second guessing.
def auto_increment
self.count += 1
end
(though, for the purposes of self documenting code, count probably is not a great variable name either)
I'm now curious to know what you would have written for documentation.
Though, I think your example turned out to be a great one because it highlights that not everyone reads code the same way. Personally, I load large segments of code into memory and then mentally step through. You left me wanting more to see the context in which the method was to be executed, but I didn't really feel the need for comments.
However, with just the one method that you wrote in your example, that seems to indicate that you read just one function at a time. If you are not observing the code as whole, I guess a comment would help. I often find them taxing though, as they have to be read into memory as well.
I think that discrepancy is why the comments vs. self-documenting code debate exists.
The problem was I initially hinted at the context in my first example, with a call to Rails' `before_create` callback method. I then omitted it from every other example, thinking it'd be inferred. Evidently that wasn't very clear.
But the way in which people read code is an interesting point, which I actually think might be worthy of its own discussion. Looking at the psychology behind this would be good, I think.
Actually, I would say your intent there was quite clear, which is where I came to realize that the code did nothing. Without that context, one could assume the method was used for its return value where the code could very well have had purpose as written.
What wasn't clear was how the count attribute was intended to be used throughout the rest of application. In the real world I would start to build a mental model around the uses of count, which was not available from your example. In terms of self-documenting code, I liken a short code snippet like your example to a sentence fragment in english. The entire sentence, or statement if you will, encompasses much more of the codebase.
This is definitely an fascinating topic, but unfortunately one that is very difficult to discuss for many reasons. I wonder how we can dig into the physiology aspects that you raise without the prevalent "my way is the only true way" attitude?
Now we just put the comment in the variable name. The compiler just checks the variable names all match up, but doesn't check whether their names make sense.
Perhaps the example chosen was too much of a toy to yield valuable insight?
Do you have github/sourceforge? I'd love to read some of your non-trivial code.
I'm not trying to be an a$$hole btw. I am not a coding guru, I genuinely want to minimize the need for comments in my code and am willing to learn from examples.
Do you have github/sourceforge? I'd love to read some of your non-trivial code.
Read almost any non-trivial successful project for good examples. The Linux kernel. Firefox. etc. The frequency and verbosity of comments tends to have a direct correlation with the simplicity of the code (which is the exact opposite of normal expectations).
Have you written any large projects that you've had to maintain over years, or worked with large teams, or handed off maintenance of a large project to others?
Two projects that are enormous successes, both with more contributors than any code that you've ever touched, I would wager. "Messes". Indeed.
To your questions, while you're rhetorically asking, trying to wink to the crowd in the implication that the answers are telling, yes, actually I have. To very good effect. I'm speaking from actual experience here, not just the hilarious patter of the bottomfeeder that is far too typical on HN.
> Two projects that are enormous successes, both with more contributors than any code that you've ever touched, I would wager.
No.
> "Messes". Indeed.
Yes, messes. Why do you think Chrome is eating Firefox's lunch ? Google has both a better-implemented product and sufficient marketing clout to push it.
Have you worked on Linux kernel code?
> I'm speaking from actual experience here, not just the hilarious patter of the bottomfeeder that is far too typical on HN.
What have you worked on?
I've worked on FreeBSD, Mac OS X, and an assortment of smaller widely used software projects, including user-facing applications.
Why do you think Chrome is eating Firefox's lunch?
Humorous given that both webkit and from that Chromium are largely comment free. What nonsense are you arguing again?
I've worked on FreeBSD, Mac OS X, and an assortment of smaller widely used software projects, including user-facing applications.
"Worked on" in HN parlance means "I did a coop term and wrote some test cases for some irrelevant little utility". Given your comical claims about Linux and Firefox re: Chrome, I have enough information about your skills.
You clearly have no idea what you're talking about. I hope I never get stuck cleaning up your messes, but chances are that someone as intellectually lazy as you -- if not you -- will leave me an uncommented code base to maintain.
The fact that you actively advocate intellectual laziness is distressing.
Intellectually lazy? That's a mighty big term for someone like you.
Further it's utterly astonishing that you would equate writing clear and non-ambiguous code rather than nebulous code of uncertain purpose -- like the example Chromium code you linked -- is "intellectual laziness". That you hold good coding as deficient compared to lazy commenting is hardly surprising given your comments.
Failing to document code is to the detriment of future maintainers. Anyone that claims their code is clear and ambiguous without comments is lying to everyone, including themselves, as a means to justify their intellectual laziness.
"I don't need to comment" is really "I don't want to document my work because that's boring and I'm much too smart to need to do that".
You're not that smart. If you were, you'd realize just how dumb everyone is, and thus, just how necessary comments are.
Making the machine check as much as possible about your code is a worthy and practical goal. I often try long and hard to capture as many invariants as possible in the type system. And even though the language that we are using, Haskell, has one of the strongest typesystems you can find, that's still not very much logic guaranteed by the compiler. Of course, run time checks can catch a few more errors, but I'd rather catch mistakes as early as possible.
You seem to have lots of experience with expressing intent in code, and making that intent 'canonical'. How do you make the machine check the accuracy of your code? What language are you using for that?
They are the crutch of people who can't read code: "Add more comments because otherwise I can't make sense of what the statements are doing." It is the English speaker demanding that every French passage have an English translation, rather than simply learning French.
They are the crutch of people who can't write code. "My code is a gigantic, illiterate mess, so instead read the comment at the top that has no guarantee of being robust or accurate."
Bringing up mathematicians and Knuth are both irrelevant distractions. Software development in the modern world is a very structure, self-describing affair, or at least it should be. Comments are the short-circuit from having to figure out how to do that.