8 ms·

Many people think their subjective comments are clear! Code doesn't lie, comments do.

MrGilbert 4y ago
Yet, code might not tell the whole story. It's a pitty.
afandian 4y ago
I wouldn’t use the word ‘lie’ but plenty of Rails code I’ve seen has mystery effects and hard to follow coupling due to monkey patching and the like. Comments please.
lordgroff 4y ago
So train people to write better comments, because although code doesn't lie (questionable as that is since the intent behind the code and what it does doesn't always align) it can be literally the worst implantation of an algorithm imaginable, and so we teach people how to code. Teaching people how to comment is a skill that's just as important and nothing turns me off a project faster than the "code is its own documentation" mantra.
- afarrell 4y ago
  How much do you charge to run training sessions on how to write better comments?
  - Psyladine 4y ago
    Here's a free method that's twice as much work but produces great results: immediately after composing, for each step and nested step, write a line or two of what its place in the code is for. Write it as though the code is broken and you're following the imaginary line threading through, explained as if to your rubber duck. Then, having written out the business logic map, look at each written step and see if they're just a description of the logic "iterates through file, passes hits onto nextFunc" and you can safely delete those. They're just glue, really, holding processes together. What you'll have left is skeletal comments that are restricted to "we did this because this stackoverflow post gave the solution" as well as those mental maps of the solution in your head, which is really what comments are for, future programmers to grok your state of mind and thus better implement their code changes.
- ajross 4y ago
  This is misunderstanding the point. Code cannot lie. Reading code (correctly) gives you a correct understanding of the state of the system, no matter how clear or unclear it is. Reading comments only tells you what the person who wrote the comment believed. It does not tell you anything in particular about how the system behaved, you have to trust the other human beings (in general a long succession of them) to have understood it correctly. And any one of you can mess that up. Saying good comments have value is fine. But their ability to lie is unique; code doesn't have that misfeature. You can't make comments lie-free by fiat, for the same reason that you can't train your developers not to write bugs. Given that, IMHO comments have limited value. Don't be a zealot in either direction, but when debugging hard problems, train yourself to ignore the lying comments.
  - agalunar 4y ago
    This is a good point, and I'm not arguing with it, but I don't think the words "code cannot lie" are the right way to express it. Code can deceive even if, definitionally, the code states what the computer will do. So code most certainly can lie. [By analogy, you'd still feel lied to if someone told you something that is technically correct but very misleading: "(Me) It's going to rain tomorrow." → tomorrow comes → "(You) It isn't raining today!" → "(Me) It is raining, in Japan. I didn't say it would rain here."] I suppose it depends on whether you're considering what the code communicates to the machine or what it communicates to a person.
    - galangalalgol 4y ago
      How about "code does what it does but comments say what it might have once, and possibly still might do?" You can have your pipeline regression test code, but not comments. Just recently my mentee found some of my code where I had changed the code but not the comment. I'm a horrible human and wasted his time. If that comment hadn't existed the code might have taken a moment to understand but as it was, he wasn't sure which was the intent.
  - _AzMoo 4y ago
    While code gives you a correct understanding of the state of the system, it doesn't give you any understanding of why the system is in that state. That's the point from the OP. Code tells you what a system is doing, not why it was designed to be that way. Comments that try and explain what a system is doing can absolutely be wrong and therefore problematic, but there's no way for code to convey the context in which it was implemented a particular way, which is what comments are for. Code without comments only gives half the story. It gives you the what, not the why.
- ac50hz 4y ago
  +10 It sounds like we have had similar experiences and have come to similar conclusions. Learning to code, learning to comment and learning to log are all ways to learn to communicate and represent a means to risk-reduction and importantly, to cost-reduction.
saiya-jin 4y ago
Comments shouldn't be there if they are not maintained in same way code is, meaning there isn't shared understanding in the team about their importance. And important they will be if you actually maintain your code, or somebody else is. Adding few comments means you show respect for their time (and sanity) so they can focus on delivering changes or fixes instead of just grokking your crap. Every time I see 0 comment in complex logic I attribute it to laziness of coder. And of course every time excuse is the same - its self-documenting, you see what its doing etc. But why, what are the effects elsewhere in the system and outside, what part of business needs this is covering, what SLA it tries to cover, what are overall goals etc. can be even impossible to grok from just code itself. World is bigger than just code.
JohannesH 4y ago
Comments can lie, but so can code... function Add(int a, int b) { return a - b; } Code can lie in so, so many ways that are much more obscure and confusing than this simple example.
- JamesBarney 4y ago
  // Adds two numbers together function Add(int a, int b) { return a - b; } is even less clear.
  - rightbyte 4y ago
    Not really. You clearly see that the intent at some point was to add two numbers, and not some fiction about ADD the diagnosis or what ever.
    - ablob 4y ago
      So which one is right, the name of the function (the comment), or it's implementation?
      - rightbyte 4y ago
        Rethorical question? You can't know that without looking on how the function is used. You at least know something is strange from the comment.
  - alpaca128 4y ago
    Sure, but I don't think anyone would call this a useful comment - it's exactly the kind of comment which should be avoided. Comments don't need to describe what the code does, but if there's an unexplicable line which handles an obscure edge case you better add a comment or even you won't remember why that line exists 3 months later.
  - TedDoesntTalk 4y ago
    Because comment is out-of-date. That’s technical debt. The comment is not the problem: the developer not updating it is. You wouldn’t leave out-of-date code in a system, it would cause bugs. Why would you leave out-of-date comments? Oh, because you don’t like to write. Your strength is math and code, not writing. Now we get to the heart of the matter and not some ruse like “code is self-documenting.”
_dain_ 4y ago
> Code doesn't lie, comments do pi = 3
- hayst4ck 4y ago
  You can't attach a debugger to the comments and figure out why your code is calculating that the circumfrence of a circle with radius 1 is 6 rather than 6.28... You're proving the point of the person you are responding to. pi = 3 isn't a lie, it's the truth of the program regardless of what any comment says.
  - agalunar 4y ago
    But that is a lie. It's deceptive and misleading. The code states what the computer will do; nobody is contesting that or claiming otherwise. They were pointing out that, although part of what `pi = 3` communicates to a person (that the machine will assign the value 3 to the variable named "pi") is correct, another part of what it communicates (that 3 is close enough to the ratio between a circle's circumference and diameter for the task at hand) may be untrue – and thus a lie. The programs that people work with in their mind are not the programs (the code) that the machine runs. What the machine does is definitely more important in the moment, but the models that live in the heads of people are more important in the long term. The code that the machine runs is just one implementation, a shadow cast by the real thing from one of many angles.
hooverd 4y ago
It may not lie, but it can certainly misdirect.
pkolaczk 4y ago
Code can lie too. Example: poor naming of classes, functions and variables. A name can tell you it's doing one thing but it can be doing something different.
citrin_ru 4y ago
> Code doesn't lie, comments do Code doesn't tell the full story either. And code can contain bugs so one cannot fully trust the code too. If code/comments are out of sync it is likely that someone changed the code and forgot to update comments (which is possible to verify using VCS logs) or it may be that the comment stated the intention right but the code has a bug. Code+comments like a parity check to me - if they agree it is good, if not - I have to investigate if the comment or the code is correct.

Yet, code might not tell the whole story. It's a pitty.

I wouldn’t use the word ‘lie’ but plenty of Rails code I’ve seen has mystery effects and hard to follow coupling due to monkey patching and the like. Comments please.

lordgroff 4y ago

So train people to write better comments, because although code doesn't lie (questionable as that is since the intent behind the code and what it does doesn't always align) it can be literally the worst implantation of an algorithm imaginable, and so we teach people how to code. Teaching people how to comment is a skill that's just as important and nothing turns me off a project faster than the "code is its own documentation" mantra.

afarrell 4y ago
How much do you charge to run training sessions on how to write better comments?
- Psyladine 4y ago
  Here's a free method that's twice as much work but produces great results: immediately after composing, for each step and nested step, write a line or two of what its place in the code is for. Write it as though the code is broken and you're following the imaginary line threading through, explained as if to your rubber duck. Then, having written out the business logic map, look at each written step and see if they're just a description of the logic "iterates through file, passes hits onto nextFunc" and you can safely delete those. They're just glue, really, holding processes together. What you'll have left is skeletal comments that are restricted to "we did this because this stackoverflow post gave the solution" as well as those mental maps of the solution in your head, which is really what comments are for, future programmers to grok your state of mind and thus better implement their code changes.
ajross 4y ago
This is misunderstanding the point. Code cannot lie. Reading code (correctly) gives you a correct understanding of the state of the system, no matter how clear or unclear it is. Reading comments only tells you what the person who wrote the comment believed. It does not tell you anything in particular about how the system behaved, you have to trust the other human beings (in general a long succession of them) to have understood it correctly. And any one of you can mess that up. Saying good comments have value is fine. But their ability to lie is unique; code doesn't have that misfeature. You can't make comments lie-free by fiat, for the same reason that you can't train your developers not to write bugs. Given that, IMHO comments have limited value. Don't be a zealot in either direction, but when debugging hard problems, train yourself to ignore the lying comments.
- agalunar 4y ago
  This is a good point, and I'm not arguing with it, but I don't think the words "code cannot lie" are the right way to express it. Code can deceive even if, definitionally, the code states what the computer will do. So code most certainly can lie. [By analogy, you'd still feel lied to if someone told you something that is technically correct but very misleading: "(Me) It's going to rain tomorrow." → tomorrow comes → "(You) It isn't raining today!" → "(Me) It is raining, in Japan. I didn't say it would rain here."] I suppose it depends on whether you're considering what the code communicates to the machine or what it communicates to a person.
  - galangalalgol 4y ago
    How about "code does what it does but comments say what it might have once, and possibly still might do?" You can have your pipeline regression test code, but not comments. Just recently my mentee found some of my code where I had changed the code but not the comment. I'm a horrible human and wasted his time. If that comment hadn't existed the code might have taken a moment to understand but as it was, he wasn't sure which was the intent.
- _AzMoo 4y ago
  While code gives you a correct understanding of the state of the system, it doesn't give you any understanding of why the system is in that state. That's the point from the OP. Code tells you what a system is doing, not why it was designed to be that way. Comments that try and explain what a system is doing can absolutely be wrong and therefore problematic, but there's no way for code to convey the context in which it was implemented a particular way, which is what comments are for. Code without comments only gives half the story. It gives you the what, not the why.
ac50hz 4y ago
+10 It sounds like we have had similar experiences and have come to similar conclusions. Learning to code, learning to comment and learning to log are all ways to learn to communicate and represent a means to risk-reduction and importantly, to cost-reduction.

saiya-jin 4y ago

Comments shouldn't be there if they are not maintained in same way code is, meaning there isn't shared understanding in the team about their importance. And important they will be if you actually maintain your code, or somebody else is. Adding few comments means you show respect for their time (and sanity) so they can focus on delivering changes or fixes instead of just grokking your crap. Every time I see 0 comment in complex logic I attribute it to laziness of coder. And of course every time excuse is the same - its self-documenting, you see what its doing etc. But why, what are the effects elsewhere in the system and outside, what part of business needs this is covering, what SLA it tries to cover, what are overall goals etc. can be even impossible to grok from just code itself. World is bigger than just code.

JohannesH 4y ago

Comments can lie, but so can code... function Add(int a, int b) { return a - b; } Code can lie in so, so many ways that are much more obscure and confusing than this simple example.

JamesBarney 4y ago
// Adds two numbers together function Add(int a, int b) { return a - b; } is even less clear.
- rightbyte 4y ago
  Not really. You clearly see that the intent at some point was to add two numbers, and not some fiction about ADD the diagnosis or what ever.
  - ablob 4y ago
    So which one is right, the name of the function (the comment), or it's implementation?
    - rightbyte 4y ago
      Rethorical question? You can't know that without looking on how the function is used. You at least know something is strange from the comment.
- alpaca128 4y ago
  Sure, but I don't think anyone would call this a useful comment - it's exactly the kind of comment which should be avoided. Comments don't need to describe what the code does, but if there's an unexplicable line which handles an obscure edge case you better add a comment or even you won't remember why that line exists 3 months later.
- TedDoesntTalk 4y ago
  Because comment is out-of-date. That’s technical debt. The comment is not the problem: the developer not updating it is. You wouldn’t leave out-of-date code in a system, it would cause bugs. Why would you leave out-of-date comments? Oh, because you don’t like to write. Your strength is math and code, not writing. Now we get to the heart of the matter and not some ruse like “code is self-documenting.”

_dain_ 4y ago

> Code doesn't lie, comments do pi = 3

hayst4ck 4y ago
You can't attach a debugger to the comments and figure out why your code is calculating that the circumfrence of a circle with radius 1 is 6 rather than 6.28... You're proving the point of the person you are responding to. pi = 3 isn't a lie, it's the truth of the program regardless of what any comment says.
- agalunar 4y ago
  But that is a lie. It's deceptive and misleading. The code states what the computer will do; nobody is contesting that or claiming otherwise. They were pointing out that, although part of what `pi = 3` communicates to a person (that the machine will assign the value 3 to the variable named "pi") is correct, another part of what it communicates (that 3 is close enough to the ratio between a circle's circumference and diameter for the task at hand) may be untrue – and thus a lie. The programs that people work with in their mind are not the programs (the code) that the machine runs. What the machine does is definitely more important in the moment, but the models that live in the heads of people are more important in the long term. The code that the machine runs is just one implementation, a shadow cast by the real thing from one of many angles.

hooverd 4y ago

It may not lie, but it can certainly misdirect.

pkolaczk 4y ago

Code can lie too. Example: poor naming of classes, functions and variables. A name can tell you it's doing one thing but it can be doing something different.

citrin_ru 4y ago

> Code doesn't lie, comments do Code doesn't tell the full story either. And code can contain bugs so one cannot fully trust the code too. If code/comments are out of sync it is likely that someone changed the code and forgot to update comments (which is possible to verify using VCS logs) or it may be that the comment stated the intention right but the code has a bug. Code+comments like a parity check to me - if they agree it is good, if not - I have to investigate if the comment or the code is correct.