On Wed, 12 Sep 2007 09:00:44 -0700, Tom Phoenix wrote:
> On 9/12/07, Peter Scott <[EMAIL PROTECTED]> wrote:
>
>> If you do
>>
>> my $a = 6.023E23; # Avagadro's number
>> # Many lines of chemistry code elided
>> @elements = sort { $atomic_wt{$a} <=> $atomic_wt{$b} } @elements;
>>
>> you get
>>
>> Can't use "my $a" in sort comparison
>>
>> which is going to annoy someone who then has to change all the
>> references to Avagadro's number.
>
> That would be annoying. But why would they change dozens of $a's to
> $avogadro instead of simply fixing the sort to use the right package
> variable, as perldiag suggests?
>
> @elements = sort { $atomic_wt{$pkg::a} <=> $atomic_wt{$pkg::b} } @elements;
>
> There's no doubt that $a and $b were poor choices for sort. It's too
> bad that Larry didn't choose other names, or capitalize them, or
> something. I rarely use single-letter names for long spans of code,
> but if I did, I'd capitalize the name because $A stands out and makes
> a better name Avogadro. And you can use it during a sort().
Well, quite, and so would I. I was answering in a beginners' context,
though. The $a/$b specialness hasn't bothered *me* for a long time
and I'm sure it hasn't bothered you either. But I think your average
beginner is not au fait with perldiag and doesn't want to spelunk to the
bottom of the perldoc explanations for simple things where the explanation
turns to advanced things, when they're trying to do something that seemed
simple to begin with. That said, I'll readily admit to being solidly in
hair-splitting territory.
--
Peter Scott
http://www.perlmedic.com/
http://www.perldebugged.com/
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