Re: regexMatch (Was: substring filters using DN attributes ?)

[Rob Byrne - Sun Microsystems <Robert.Byrne@france.Sun.COM>]

Kurt,

Is there a standard definition  of what a regular expression actually is ?

I ask this because if you work on Solaris for example, there are n different
libraries and functions for doing regular expression matching so the meaning
of "regular expression" is not so obvious.

Rob.

"Kurt D. Zeilenga" wrote:

> At 09:35 AM 7/25/00 -0700, Mark C Smith wrote:
> >"Kurt D. Zeilenga" wrote:
> >>
> >> I've meaning to publish a regexMatch rule I-D which would allow
> >> matching of an asserted regular expression against the string
> >> representation of attribute values.  Of course, to be useful with
> >> DNs, we'd have to have to define a canonical string representation
> >> of DNs.  Given such, you would be able to do DN matching like:
> >>
> >>         (member:regexMatch:=.*,dc=example,dc=com$)
> >>
> >> Such a matching rule, I believe, would be generally useful in
> >> a number of applications.  Of course, user applications may
> >> not want to expose regular expressions to average Joe.
> >>
> >> If others concur that this would be generally useful, I'll put
> >> up a straw man proposal after IETF#48.
> >
> >It would be interesting to see examples of the kinds of LDAP application
> >problems that would be more easily addressed if such a matching rule was
> >available.
>
> I agree.  In fact, I wouldn't attempt to write such an I-D
> without decent examples.  In general, such a rule would be useful
> to applications which required very specific, complex matching
> which cannot easily be decomposed into a substrings assertion.
> I'll try to come up with some examples, hopefully ones which
> are not too contrived.
>
> >If all we really need is a way to anchor the start and end
> >of strings (i.e., ^ and $ from regex), I'd rather see a more narrow
> >proposal.  Why?  Because general regular expression matching will be
> >quite difficult to support using indexes, etc.
>
> I concur that general regular expressions are quite difficult to
> to support using indexing.  I also concur that applications wanting
> to make an assertion should use an appropriate matching rule.  I
> fully agree that applications wanting to simply assert start/end
> text should use a substrings matching rules.
>
> Kurt