|Just another Perl shrine|
Re (tilly) 4 (disagree): Another commenting question,by tilly (Archbishop)
|on Mar 21, 2001 at 02:17 UTC||Need Help??|
If you peruse my example and walked away from it thinking that it stands as an example of why to comment every line, use pretty formatting of comments, put comments at the end of lines where they have to be adjusted by anyone making changes to the code, etc, etc, etc - then you missed the point.
My last paragraph of what you were responding to said:
Also note that I don't actually write uncommented code. But my comments are about different aspects of the code than the mere mechanics of what each line is doing...
Stare at that carefully.
The sample commenting examples that you gave resulted in comments whose formatting would be a maintainance issue that so closely duplicate what the code says that there is little added value. Secondly the very verbosity of the comments led you to use a useless variable and a confusing comment. You claim you wouldn't use such a variable name in practice, but I only have what you wrote to judge by. And in what you wrote you used a useless variable name and a useless - confusing - comment.
The sample code I pointed you at is commented. But it is commented in a completely different way and style. Plus I can tell you how that style would change in a slightly different circumstance.
I comment. Yes. I comment intent. I highlight key points. I do not explain my algorithms. I do not explain my variable names. I do not produce a separate document for the human and the computer. And above all I have a commenting style that is not going to be a lot of work to maintain.
So if you need to change the code and make it do something else, or if you need to understand the mechanics so you can do something similar, then you will need to read the code. Humans should be able to figure out how the code does what it says it does.
Now you claim I misunderstood you and you never meant to advocate play by play commentary on the mechanics. But the examples that you gave were play by play commentary on the mechanics. The statement you made (that I cannot disagree strongly enough with) is that there is no such thing as overcommenting. The formatting of comments that you advocated poses a serious maintainance problem. You claim that overcommenting only accounts for perhaps 0.1% of comment related problems out there.
I am sorry, but I cannot reconcile these two points of view. What you are saying now does not fit what you showed as an example of what you think people should do.
I have dealt with problems due to overcommenting, poorly maintained comments, comments that only make sense if you are in the original author's point of view, comments that cover for poorly thought out code, comments whose formatting makes code hard to tinker with...and most of these problems would have either not been there or been lessened if the original programmers understood that not all comments are good.
In fact for every one of those items I either saw them in your examples of how to comment, or I saw you doing things that have lead to these errors in code that I have worked with.
Now you claim that the style of commenting that I demonstrated is what you were attempting to advocate. Well it certainly isn't what you describe. So let me explicitly explain the style that I follow:
A better way to put this might be that I do not comment on the code. I comment on the usage of the code and I comment on other code. I comment on desired changes, I comment about what is critical, and what the external dependencies are. But the code at hand should be readable and should stand as its own comment.
Now with all that in mind, please go back and read my example again and compare to this detailed summary. Does my code not fit my description? Does my code need detailed comments about how it works? Do I, despite that, comment in a useful way while requiring a minimum of work to maintain the comments as the code changes?