Re: [PEPr] +1 for XML::XML_Feed_Parser

Justin Patrin wrote:

I didn't say it was a huge difference. The difference between $a++ and ++$a is also not that big, but it makes a difference. Add up all the little tricks and you can get significant speedups. At least I have shown, for all to see, that what I've been saying is true (although I shouldn't have had to since other well-known developers also vouched for this and you should have been able to test it yourself as well).

Premature optimization is the root of all evil. Don't collect tricks for optimization. Design correctly, write readable code, and profile. Optimize on hotspots only. And never, ever, fret about optimization tricks. You'll put people on a defensive stance.

And you're still ignoring that concatenation is easier to audit. *All* syntax highlighters will highlight concatenation. Only some highlight in-string vars correctly. Besides that, it's also simpler to be able to skip over single quoted vars when looking for things like XSS or SQL injection attacks. It also means that there are no special chars in the string to watch out for.

Here is your strong point. Readability, and thus ease of auditing, is a major point to go for. You'd easily win this argument if you dropped the performance point and aimed at readability.

Using " is also more error-prone when dealing with complicated vars (and it can't be used for *really* complicated ones). On top of this it tends to promote bad array syntax ($arr[key] instead of $arr['key']). For all of these reasons (and probably some I'm missing) ' should be preferred over ".

A good list of security and readability reasons could probably go in the coding guidelines as a recomendation, no? Regards, -- Sérgio