From mboxrd@z Thu Jan 1 00:00:00 1970 Received: (from majordomo@localhost) by pauillac.inria.fr (8.7.6/8.7.3) id PAA29490; Thu, 16 Sep 2004 15:29:34 +0200 (MET DST) X-Authentication-Warning: pauillac.inria.fr: majordomo set sender to owner-caml-list@pauillac.inria.fr using -f Received: from concorde.inria.fr (concorde.inria.fr [192.93.2.39]) by pauillac.inria.fr (8.7.6/8.7.3) with ESMTP id PAA30133 for ; Thu, 16 Sep 2004 15:29:33 +0200 (MET DST) Received: from smtp3.adl2.internode.on.net (smtp3.adl2.internode.on.net [203.16.214.203]) by concorde.inria.fr (8.13.0/8.13.0) with ESMTP id i8GDTVmf021557; Thu, 16 Sep 2004 15:29:32 +0200 Received: from [192.168.1.200] (ppp202-133.lns1.syd3.internode.on.net [203.122.202.133]) by smtp3.adl2.internode.on.net (8.12.9/8.12.9) with ESMTP id i8GDTBOU052575; Thu, 16 Sep 2004 22:59:12 +0930 (CST) Subject: Re: [Caml-list] Need NFA/DFA conversion help From: skaller Reply-To: skaller@users.sourceforge.net To: Luc Maranget Cc: Diego Olivier Fernandez Pons , caml-list In-Reply-To: <20040916120724.GB16633@yquem.inria.fr> References: <1095291341.27775.1164.camel@pelican.wigram> <20040916120724.GB16633@yquem.inria.fr> Content-Type: text/plain Message-Id: <1095341350.27775.1237.camel@pelican.wigram> Mime-Version: 1.0 X-Mailer: Ximian Evolution 1.2.2 (1.2.2-4) Date: 16 Sep 2004 23:29:11 +1000 Content-Transfer-Encoding: 7bit X-Miltered: at concorde with ID 4149953B.000 by Joe's j-chkmail (http://j-chkmail.ensmp.fr)! X-Loop: caml-list@inria.fr X-Spam: no; 0.00; caml-list:01 sourceforge:01 2004:99 context-free:99 pcre:01 expressive:01 9660:01 glebe:01 regexp:01 regexp:01 compiler:01 tagged:01 implementors:01 handles:01 nsw:01 Sender: owner-caml-list@pauillac.inria.fr Precedence: bulk On Thu, 2004-09-16 at 22:07, Luc Maranget wrote: > > > What doesn't work is sub-group matching, look ahead, etc -- things > > > requiring actions in the middle of a regexp (rather than at the > > > end). > > > > textbook say. They do not accept rational or context-free languages, > > they do not use DFA, NFA or LR(k) automata as claimed. > > > > Perhaps I should make my previous post (on the theoretic side of ocamllex) > a bit more precise. > > The cited articles relate to << sub-group matching >> in DFA implementation > of regexp matching. > > The proposed technique is an extension of the Dragon-Book technique > (Glukov ?) I have read the Laurikari article and it describes the kind of thing I was looking for. It provides a mathematical formalism for Tagged NFAs and gives an modification of the subset construction which handles determinising such TNFAs. I think this gives all the functionality of lex and Str/PCRE together (except for back references). That seems a reasonable goal for a first release because it can simplify the life or ordinary programmers as well as compiler implementors. Perhaps more expressive automata will follow (as well as performance improvements :) -- John Skaller, mailto:skaller@users.sf.net voice: 061-2-9660-0850, snail: PO BOX 401 Glebe NSW 2037 Australia Checkout the Felix programming language http://felix.sf.net ------------------- To unsubscribe, mail caml-list-request@inria.fr Archives: http://caml.inria.fr Bug reports: http://caml.inria.fr/bin/caml-bugs FAQ: http://caml.inria.fr/FAQ/ Beginner's list: http://groups.yahoo.com/group/ocaml_beginners