http://www.perlmonks.org?node_id=879417


in reply to Re^2: On comments
in thread On comments

Sorry, but bad comments do not make up for bad code.

All of this:

Can be replaced by:

{ local( $trace, $single, $^D ); ($evalarg) = $evalarg =~ /(.*)/s; # Untaint # $usercontext built in DB::DB @res = eval "$usercontext $evalarg;\n"; # '\n' for nice recur +sive debug }

Not only is it shorter and clearer, it is safer. As tchrist points out in the above code:

# 'my' would make it visible from user code # but so does local! --tchrist

You've gone to great verbosity to explain how the variables: $otrace, $osingle, $od, are used to prevent the user code from messing with the debugger's internal state. Completely missing the fact that by storing copies in those localised globals, it is just as likely that the user code will mess with those variables as the originals. And if they do, the code will be restoring the messed with values over the top of the untouched original values.

Whereas if you simply localise the original globals, they'll be restored when the block exits regardless of what the user does. And the need for all the code-concealing and confusing comments just goes away.

I can see from what you've done to perl5db.pl that we'll never agree. That's fine. Some people like marmite, some don't.

But, the last four paras of your post above show me that you've either not read Programming *is* much more than "just writing code"., or you have and still think you can justify your position by concluding that those with the opposed viewpoint are either too lazy or too arrogant to comment. And that is just plain not the case.

I rarely comment because I've found over the years that the vast majority of comments tell me nothing more than the code does. But worse, as above, the comments attempt to persuade me stuff that is just flat out wrong.

Even your point that "Not every programmer is going to be as brilliant as every other." totally misreads that reasoning. For example, any programmer unfamiliar with local--which is a larger portion of modern Perl programmers--will, from reading your comments above, get entirely the wrong idea about what it does and how it works. And will go away with entirely the wrong impression because of those bad comments.

If however, there were no comments, they would have had to have gone to the documentation, and read up about the local keyword and learnt what it really does.

Like I said. Bad comment are worse than no comments. And most comments are bad. Even those by people who think they write good ones.


Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.
"Science is about questioning the status quo. Questioning authority".
In the absence of evidence, opinion is indistinguishable from prejudice.