Re: [Chicken-users] Chicken vs Perl

[Daishi Kato]

At Tue, 20 Sep 2011 15:18:30 +0200,
Peter Bex wrote:
> 
> On Tue, Sep 20, 2011 at 10:08:16PM +0900, Daishi Kato wrote:
> > Hi,
> > 
> > My situation is pretty similar to yours, meaning I used to use Perl
> > and later started using Chicken for my job.
> > 
> > Running your scripts on my machine produced similar result
> > (about 10 times difference).
> > 
> > -unsafe option in csc-4.6.0 didn't work (no change).
> > -unsafe-libraries in csc-4.0.0 did work (a little faster),
> > but it's not available in csc-4.6.0 (does anybody know why?).
> > 
> > I also tried with csc-4.7.0, and guess what, it's a little slower
> > (at least on my test data. I partially crawled wiki.call-cc.org).
> > Peter, how could this happen?
> 
> This probably depends on the nature of your regex.  We made the
> tradeoff that large consecutive ranges of characters are stored
> more efficiently as a range instead of as separate characters.
> This means that if you are using a regex with many separate chars
> it could be slightly slower.
> 
> In some cases regexes can't be compiled to DFA but need to use
> backtracking, which is comparatively slow.   That's not the case
> in Sascha's regex (I checked), but might be the reason it's slow
> for you.

I would like to note that I used the script that Sascha posted.

Let me try with a somewhat larger test set.

% wget -r -l2 http://wiki.call-cc.org/manual/index
% du -s wiki.call-cc.org
2528    wiki.call-cc.org

% time /usr/local/chicken-4.7.0/bin/csi -s a.scm wiki.call-cc.org > /dev/null
/usr/local/chicken-4.7.0/bin/csi -s a.scm wiki.call-cc.org > /dev/null  3.88s 
user 0.16s system 85% cpu 4.708 total

% time /usr/local/chicken-4.6.0/bin/csi -s a.scm wiki.call-c
c.org > /dev/null
/usr/local/chicken-4.6.0/bin/csi -s a.scm wiki.call-cc.org > /dev/null  3.13s 
user 0.13s system 86% cpu 3.771 total

% grep regexp a.scm
(define href (regexp "href=\"(http://[^\"/?]+)([\"/?].*)" #t))

% uname -r -v -o
2.6.39-2-686-pae #1 SMP Tue Jul 5 03:48:49 UTC 2011 GNU/Linux


Best,
Daishi