Re: [HACKERS] regular expressions from hell - Mailing list pgsql-hackers

> I've noticed there are no less then 10^10 regex implementations.
> Is there a standard?  Does ANSI have a regexp standard, or is there
> a regex standard in the ANSI SQL spec?  What do we use?
>
> Personally, I'm a perl guy, so everytime I have to bend my brain to
> some other regex syntax, I get a headache.  As part of my perl PL
> package, perl regexps will be included as a set of operators.
>
> Is there interest in the release of perl-style regexp operators for
> postgres before the PL is completed?  Note that this requires the
> entire perl library to be loaded when the operator is used (possibly
> expensive).  But, if you have a shared perl library, this only has to
> happen once.

Well, not to bring this up for discussion again, but there is apparently
a Posix standard, and even better a free implementation:


Article 10705 of comp.os.linux.misc:
Newsgroups: gnu.announce,gnu.utils.bug,comp.os.linux.misc,alt.sources.d
Subject: Rx 1.9
Date: Wed, 10 Jun 1998 10:40:00 -0700 (PDT)
Approved: info-gnu@gnu.org

The latest version of Rx, 1.9, is available on the web at:

    http://users.lanminds.com/~lord
    ftp://emf.net/users/lord/src/rx-1.9.tar.gz
 and at ftp://ftp.gnu.org/pub/gnu/rx-1.9.tar.gz and mirrors of that
                                                site (see list below).

Rx is a regexp pattern matching library. The library exports these
functions which are standardized by Posix:

     regcomp         - compile a regexp
     regexec         - search for a match
     regfree         - release storage for a regexp
     regerr          - translate error codes to strings

The library exports many other functions as well, and does a lot
more than Posix requires.

                RECENT CHANGES

1. Rx 1.9
   Recent changes: More "dead code" was recently discarded,
           and the remaining code simplified.

           Benchmark comparisons to GNU regex and older
           versions of Rx were added to the distribution.

0. Rx 1.8
   Recent changes: Various bug-fixes and small performance improvements.
           A great deal of "dead code" was recently discarded,
           making the size of the Rx library smaller and the
           source easier to maintain (in theory).


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