RE: [OT?] Coding Style

Jonathan Earle
2001-01-22T18:01:26Z

> -----Original Message-----
> From: Larry McVoy [mailto:lm@bitmover.com]
>
> On Mon, Jan 22, 2001 at 11:04:50AM -0500, Jonathan Earle wrote:
> > > -----Original Message-----
> > > From: profmakx.fmp [mailto:profmakx.fmp@gmx.de]
> > >
> > > So, every good programmer
> > > should know where to put comments. And it is unnecessary to
> > > put comments to
> > > explain what code does. One should see this as stated in the
> > > CodingStyle doc.
> > > Ok, there are points where a comment is good, but for example
> > > at university
> > > we are to comment on every single line of code ...
> >
> > WRONG!!!
> >
> > Not documenting your code is not a sign of good coding, but
> rather shows
> > arrogance, laziness and contempt for "those who would dare
> tamper with your
> > code after you've written it". Document and comment your
> code thoroughly.
> > Do it as you go along. I was also taught to comment nearly
> every line - as
> > part of the coding style used by a large, international
> company I worked for
> > several years ago. It brings the logic of the programmer
> into focus and
> > makes code maintenance a whole lot easier. It also helps
> one to remember
> > the logic of your own code when you revisit it a year or more hence.
>
> Please don't listen to this. The only place you really want
> comments is
>
> a) at the top of files, describing the point of the file;
> b) at the top of functions, if the purpose of the
> function is not obvious;
> c) in line, when the code is not obvious.
>
> If you are writing code that requires a comment for every
> line, you are
> writing bad, obscure, unobvious code and no amount of
> commenting will fix
> it.

The point of comments is not to "fix" bad code, it's to provide
understanding. As the original poster said, _you_ may understand your code,
but that in no way implies that _I_ will, or your co-worker down the hall
will, etc. I'm not suggesting that a statement like "counter=0;" at the
start of a function be commented, but other operations should be. "Why do
we want this file written in /proc - wouldn't syslog have worked better?"
"Why is this loop skipping the first seven elements?" "Why is this
structure used here instead of a simple array?" "What on earth does
m->n->o->num represent?"

> The real reason to sparing in your comments is that code and
> comments are
> not semantically bound to each other: the program doesn't
> stop working when
> the comment becomes incorrect. It's incredibly frustrating
> to read a comment,
> believe you understand what is going on, only to find out
> that the comment
> and the code no longer match.

Comments should be updated when code is updated. I believe that
documentation is of far greater value than code itself. Code can be
changed, however, logic drives the code. Without a good understanding of
the latter, the former is of little value, IMHO.

Cheers!
Jon