[aklug] Re: perl lists question, sorting, sort of.

On Wed, Aug 18, 2010 at 01:25:30AM -0800, Arthur Corliss wrote:
> Consistency is a big part of secure programming, Mike.

I seem to remember a quote about foolish consistency somewhere..

> Now, if you'd like to share an anecdote of an instance where you found the
> opposite, please share. But it needs to be more than "unmaintainable
> because it utilized a convention I disliked".

You want rational, and you want an anecdote.. interesting. I shall
share an anecdote, then. I was discussing a regex on AKLUG mailing
list, and..

The point is, you used 'split /\./sm, $s'. Were I to see this without
the context of this discussion, this would be a red flag. I would have
to spend extra time trying to determine why you used /sm when it has no
effect on the existing code. Did you neglect something in your regex?
Is the regex accomplishing what it should? What should it accomplish,
anyways?

If you used '/foo .* bar/sm', I would also have to spend extra time
trying to determine why you used /m. Did you neglect an anchor? There
should be a name for this sort of thing; anti-bug, perhaps. It makes
you look for problems where there are none (maybe).

Superfluous code, that is, code that is completely unnecessary, makes
your intent unclear. This has nothing to do with convention, unless the
convention is "throw code at it until it sticks." You may consider
unclear intent a bugaboo, but it has real implications for debugging;
nearly every day I have to dig into someone's source code trying to
figure out what the hell they were thinking.

I can give you an example of unclear intent leading me down the wrong
path for quite some time. I was maintaining an e-commerce system
written by an author I will not name. It was double-escaping HTML
coming out of a database; when I looked at the code responsible, there
was only one level of escaping. I assumed this was correct. I then had
to dig through the rest of the code trying to find where it was being
escaped again during presentation, but I could not find anything. I
then had to expand the search to code not responsible for presentation,
and found that the HTML was being escaped -prior- to being inserted into
the database.

The initial HTML escaping I had found was, arguably, the error.

Perhaps not an example of superfluous code, but I couldn't resist using
this as an example of unclear intent.

--
Michael Fowler
www.shoebox.net
---------
To unsubscribe, send email to <aklug-request@aklug.org>
with 'unsubscribe' in the message body.