[TYPO3-core] RFC: T3-speedup preg insted of ereg

[Martin Kutschker]

Michael Stucki <michael at typo3.org> writes on 
Sat, 05 Nov 2005 00:52:05 +0100 (MET):

> 
> - Kasper checks for empty strings using strcmp, you make a "==="
> check instead. Is there any difference between them? Which of those
> methods is faster?


Theoretically === should be faster because it has no function call.


> - Sometimes, you write complicated expressions like this one:
> 
> if (preg_match('/^([^\<\>]*\-\-\>)?(.*?)(\<\!\-\-[^\<\>]*)?$/s',
> $content,
> $matches)===1) {


Why ist practically every character escaped? There is NO need to escape any character (except ]) in a character class ( eg [abc>]). Outside of character classes only regexp meta chars like . and * must be escaped.

This the above regexp can be safely written like this:

preg_match('/^([^<>]*-->)?(.*?)(<!--[^<>]*)?$/s', ...);

Hint: if you need brackets for grouping but don't need the match you can write (?:expr). expr will match but won't appear in the match array. This is also a bit faster.

eg.

preg_match('/^(?:[^<>]*-->)?(.*?)(?:<!--[^<>]*)?$/s', ..., $matches);

In $matches[1] you will find the content of the 2nd bracket.


> > Branches:
> > HEAD, 3.7(?), 3.8(?)
> 
> I guess this change is much too big for maintenance releases. So it is
> for HEAD only, right?
> 
> Regards, and thumbs up!


+1 for HEAD

Masi