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List:       kfm-devel
Subject:    Re: Regexp stuff is KJS.
From:       Michael Bedy <mjbedy () mediaone ! net>
Date:       2001-01-31 2:07:59
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On Tue, 30 Jan 2001, Andreas Pour wrote:

> 
> Hi,
> 
> You may take a look at ftp://ftp.csx.cam.ac.uk/pub/software/programming/pcre/. 
> This is quite cross-platform (it's used in php which runs just about
> everywhere) and has the backticks, look-aheads, conditional matches, yada yada
> yada.
> 
> It would actually be really cool to wrap this in C++ and include it in
> kdelibs.  Would save tons of programming time on many things that do not
> require super-optimization.
> 
> But wait -- it's already been wrapped in C++.  See
> http://regx.sourceforge.net/.
> 

   Cool!

   This could make life a lot easier :-)

   Thanks,
     - Mike


> Ciao,
> 
> Andreas
> 
> 
> Michael Bedy wrote:
> > 
> > On Tue, 30 Jan 2001, Harri Porten wrote:
> > 
> > > Michael Bedy wrote:
> > > >
> > > >   Well, I have looked over the regexp stuff, and there are a few ways to
> > > > proceed, as I see it..
> > > >
> > > >    1) Write a complete regexp package.
> > > [...]
> > > >    2) Rip the regexp stuff out of glibc and hack away.
> > >
> > > I always was under the impression that we just have to map a few
> > > functions (e.g. for retrieving captures) and that's all. What exactly is
> > > missing ? It would really be a dumb move by the authors of the spec if
> > > they require functionality not being provided by regular system libs.
> > >
> > 
> >   The spec says it's "modelled after the regular expression facility in
> > the perl 5 programming language."
> > 
> > > >    3) Write a "preprocessor" that converts a Javascript regexp into an
> > > >       POSIX one. Then use the POSIX stuff as it does now.
> > >
> > > That's the way *I* intended to go. Under the assumption that the
> > > differences would be rather minor, of course. Even if - let's say - 5%
> > > of the features can't be done that way I would simply skip them unless
> > > they are proven to be used in real world web pages.
> > >
> > 
> >    Oh, I don't WANT to write a regex package. I've got a good idea how
> > much work that would be.
> > 
> >    The POSIX spec (at least as presented by the documents I have found on
> > the web) has several significant differences from JS. As an example, JS
> > allows things like "\w" which matches any "word" character. POSIX has
> > [:alnum:], which I think means the same thing.
> > 
> >    So far, I have determined that at least one (evil) feature of JS just
> > can't be done with POSIX (at least, not at the same time as tons of more
> > interesting stuff): backreferences.
> > 
> >    One additional option: GLIBC has a seperate interface to it's regular
> > expression stuff, and it may provide almost all of the constructs
> > required. Pros: easy, Cons: only woks on GLIBC systems.
> > 
> >    Or, another (heavy) option is to link to libperl and use it, since JS
> > regex is taken pretty much word for word from perl.
> > 
> >      - Mike
> 
> -- 
> Ciao,
> 
> Andreas Pour
> 
> http://www.kde.com/ :  Everything KDE
> http://apps.kde.com/:  The Latest in KDE Applications
> 

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