On Sun, Feb 19, 2012 at 1:55 AM, Tom Lane <t...@sss.pgh.pa.us> wrote: > Dimitri Fontaine <dimi...@2ndquadrant.fr> writes: >> Tom Lane <t...@sss.pgh.pa.us> writes: >>> Yeah ... if you *don't* know the difference between a DFA and an NFA, >>> you're likely to find yourself in over your head. Having said that, > >> So, here's a paper I found very nice to get started into this subject: >> http://swtch.com/~rsc/regexp/regexp1.html > > Yeah, I just found that this afternoon myself; it's a great intro. > > If you follow the whole sequence of papers (there are 4) you'll find out > that this guy built a new regexp engine for Google, and these papers are > basically introducing/defending its design. It turns out they've > released it under a BSD-ish license, so for about half a minute I was > thinking there might be a new contender for something we could adopt. > But there turn out to be at least two killer reasons why we won't: > * it's in C++ not C > * it doesn't support backrefs, as well as a few other features that > maybe aren't as interesting but still would represent compatibility > gotchas if they went away.
Another interesting library, technology-wise, is libtre: http://laurikari.net/tre/about/ http://laurikari.net/tre/documentation/ NetBSD plans to replace the libc regex with it: http://netbsd-soc.sourceforge.net/projects/widechar-regex/ http://groups.google.com/group/muc.lists.netbsd.current-users/browse_thread/thread/db5628e2e8f810e5/a99c368a6d22b6f8?lnk=gst&q=libtre#a99c368a6d22b6f8 Another useful project - AT&T regex tests: http://www2.research.att.com/~gsf/testregex/ About our Spencer code - if we don't have resources (not called Tom) to clean it up and make available as library (in short term - at least to TCL folks) we should drop it. Because it means it's dead end, however good it is. -- marko -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
