Re: Regex in PHP

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On Wed, 2008-06-04 at 23:20 -0400, Nathan Nobbe wrote:
>
> i repeated your test using the time program and splitting the script into 2,
> one for each strpos and stripos, to find similar results.  imo, there is no
> need for 2 comparisons for case-insensitive searches, because both arguments
> can be converted to a single case prior to the search.  obviously, there is
> a small amount of overhead there the case-sensitive search is unencumbered
> by.  i guess i never sat down and thought about how that algorithm would
> work (case-sensitive) =/.
> 
> thanks for the tips rob.  sorry to bother you richard.

You would do two comparisons... why incur the overhead of a conversion
if one is not necessary. First you do case sensitive match, if that
fails then you try the alternative version comparison. It is inefficient
to perform 2 conversions and a single comparison in contrast. Similarly,
it's very inefficient to convert two entire strings then perform a
comparison. If the first characters differ then conversion of the rest
of the strings was pointless. This is basic algorithms in computer
science.

Cheers,
Rob.
-- 
http://www.interjinn.com
Application and Templating Framework for PHP


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