[cl-ppcre-devel] slow matching

[Carlos Konstanski]

On Thu, 17 Jul 2008, Edi Weitz wrote:

> Date: Thu, 17 Jul 2008 22:01:40 +0200
> From: Edi Weitz <edi at agharta.de>
> Reply-To: General interest list about cl-ppcre
>     <cl-ppcre-devel at common-lisp.net>
> To: General interest list about cl-ppcre <cl-ppcre-devel at common-lisp.net>
> Subject: Re: [cl-ppcre-devel] slow matching
> 
> On Thu, 17 Jul 2008 08:55:23 -0600, Carlos Konstanski <ckonstanski at pippiandcarlos.com> wrote:
>
>> I was not on the list at the time that Edi posted the message
>> "1.4.0/1 performance" which is why I am posting a new one instead of
>> replying.
>>
>> I am using threaded SBCL 1.0.18 on gentoo amd64.  On my platform,
>> matching has slowed to a crawl.  It takes 1.5 to 2 seconds to
>> perform the following match:
>>
>> (cl-ppcre:all-matches-as-strings "^\\d\\d\\d\\d-\\d\\d-\\d\\d\\d\\d:\\d\\d:\\d\\d\.0$" <anystring>)
>>
>> I'm sure I could write this regex better.  Nevertheless it runs
>> hundreds of times slower than it did previously.
>>
>> I'll test on the same setup with x86 and give a report.
>
> No need to do that, I just tested on x86 and it looks just as bad
> there.  The good news is that I have a completely re-factored CL-PPCRE
> on my hard disk which will be released in a couple of days and which
> won't have this problem anymore, so stay tuned.
>
> Thanks for the report,
> Edi.

I just noticed the new 2.0 version, and it works like a champ!  Thanks
so much for getting that released.  I will bug the gentoo lisp herd to
get it updated in their overlay.

Your English is quite amazing, by the way.  I was tempted to write my
posts in German, but you can probably read my English more easily.

Carlos Konstanski