[cl-ppcre-devel] Need help with a slow regexp

[Edi Weitz]

On Mon, 24 Jan 2005 15:24:47 -0500, pete-cl-ppcre at kazmier.com wrote:

> It is better now.  However, I am no longer using DO-REGISTER-GROUPS
> as I realized that I intended to use REGISTER-GROUPS-BIND all along.
> In any case, I am thrilled with the performance of cl-ppcre now that
> I have set *regex-char-code-limit* to an appropriate value.

Actually, if your Lisp implementation has a decent hash table
implementation the value of *REGEX-CHAR-CODE-LIMIT* shouldn't matter
much during scanning - only when a regular expression is created.

The problem that I fixed in 1.1.0 was that your function created a new
scanner each time it was called although this wasn't necessary.  This
resulted in much too much consing (because of the huge hash tables
that were generated).

> I think your library is great, my only problem now is the
> performance of READ-LINE in the free CL implementations (which is
> certainly not your problem).  Its absolutely terrible in SBCL.  I've
> inquired about it, but have not really received any good responses
> yet:
>
> http://sourceforge.net/mailarchive/forum.php?thread_id=6400934&forum_id=4133

Yeah, I've read that and I'm concerned, too.  I'd love to see an
encouraging response.  Have you tried to download the trial versions
of AllegroCL and/or LispWorks just to check how they cope with this?

Cheers,
Edi.