GNU bug report logs - #1260
regex.c and RE_FRUGAL

Package: emacs;

Reported by: "Alexander V. Lukyanov" <lav <at> netis.ru>

Date: Mon, 27 Oct 2008 16:05:04 UTC

Severity: normal

Done: Stefan Monnier <monnier <at> iro.umontreal.ca>

Bug is archived. No further changes may be made.

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Report forwarded to bug-submit-list <at> lists.donarmstrong.com, Emacs Bugs <bug-gnu-emacs <at> gnu.org>:
bug#1260; Package emacs. Full text and rfc822 format available.

Acknowledgement sent to "Alexander V. Lukyanov" <lav <at> netis.ru>:
New bug report received and forwarded. Copy sent to Emacs Bugs <bug-gnu-emacs <at> gnu.org>. Full text and rfc822 format available.

Message #5 received at submit <at> emacsbugs.donarmstrong.com (full text, mbox):

From: "Alexander V. Lukyanov" <lav <at> netis.ru>
To: bug-gnu-emacs <at> gnu.org
Subject: regex.c and RE_FRUGAL
Date: Mon, 27 Oct 2008 18:56:11 +0300

Hello!

This bug report is not quite for emacs, but for its regex library.

It features RE_FRUGAL flag (very useful), but it does not seem to work.

I have tried this rather simple program and it prints 0-12 instead of expected 0-6.

Please advice.

#include "config.h"
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include "regex.h"
int main()
{
   const char *rexp="<.*?>";
   static struct re_pattern_buffer rexp_c;
   static struct re_registers regs;
   re_syntax_options = RE_FRUGAL;
   re_compile_pattern(rexp,strlen(rexp),&rexp_c);
   if(re_search(&rexp_c,"<html><head>",12,0,12,&regs)==-1) {
      printf("search failed\n");
      return 1;
   }
   printf("%d-%d\n",regs.start[0],regs.end[0]);
   return 0;
}

--
   Alexander.

Information forwarded to bug-submit-list <at> lists.donarmstrong.com, Emacs Bugs <bug-gnu-emacs <at> gnu.org>:
bug#1260; Package emacs. Full text and rfc822 format available.

Acknowledgement sent to Stefan Monnier <monnier <at> iro.umontreal.ca>:
Extra info received and forwarded to list. Copy sent to Emacs Bugs <bug-gnu-emacs <at> gnu.org>. Full text and rfc822 format available.

Message #10 received at submit <at> emacsbugs.donarmstrong.com (full text, mbox):

From: Stefan Monnier <monnier <at> iro.umontreal.ca>
To: "Alexander V. Lukyanov" <lav <at> netis.ru>
Cc: 1260 <at> debbugs.gnu.org, bug-gnu-emacs <at> gnu.org
Subject: Re: bug#1260: regex.c and RE_FRUGAL
Date: Tue, 28 Oct 2008 04:17:45 -0400

> This bug report is not quite for emacs, but for its regex library.
> It features RE_FRUGAL flag (very useful), but it does not seem to work.
> I have tried this rather simple program and it prints 0-12 instead of
> expected 0-6.

IIRC you'll need to set RE_NO_POSIX_BACKTRACKING as well, otherwise the
match returned will always be the longest.


        Stefan

Information forwarded to bug-submit-list <at> lists.donarmstrong.com, Emacs Bugs <bug-gnu-emacs <at> gnu.org>:
bug#1260; Package emacs. Full text and rfc822 format available.

Acknowledgement sent to "Alexander V. Lukyanov" <lav <at> netis.ru>:
Extra info received and forwarded to list. Copy sent to Emacs Bugs <bug-gnu-emacs <at> gnu.org>. Full text and rfc822 format available.

Message #20 received at submit <at> emacsbugs.donarmstrong.com (full text, mbox):

From: "Alexander V. Lukyanov" <lav <at> netis.ru>
To: Stefan Monnier <monnier <at> iro.umontreal.ca>
Cc: 1260 <at> debbugs.gnu.org, bug-gnu-emacs <at> gnu.org
Subject: Re: bug#1260: regex.c and RE_FRUGAL
Date: Tue, 28 Oct 2008 14:57:39 +0300

On Tue, Oct 28, 2008 at 04:17:45AM -0400, Stefan Monnier wrote:
> > This bug report is not quite for emacs, but for its regex library.
> > It features RE_FRUGAL flag (very useful), but it does not seem to work.
> > I have tried this rather simple program and it prints 0-12 instead of
> > expected 0-6.
> 
> IIRC you'll need to set RE_NO_POSIX_BACKTRACKING as well, otherwise the
> match returned will always be the longest.

Thank you! The flag RE_NO_POSIX_BACKTRACKING did the trick.

Is there a reason for RE_SYNTAX_EMACS including RE_FRUGAL and not including
RE_NO_POSIX_BACKTRACKING?

-- 
   Alexander.

Information forwarded to bug-submit-list <at> lists.donarmstrong.com, Emacs Bugs <bug-gnu-emacs <at> gnu.org>:
bug#1260; Package emacs. Full text and rfc822 format available.

Reply sent to Stefan Monnier <monnier <at> iro.umontreal.ca>:
You have taken responsibility. Full text and rfc822 format available.

Notification sent to "Alexander V. Lukyanov" <lav <at> netis.ru>:
bug acknowledged by developer. Full text and rfc822 format available.

Message #30 received at 1260-done <at> emacsbugs.donarmstrong.com (full text, mbox):

From: Stefan Monnier <monnier <at> iro.umontreal.ca>
To: "Alexander V. Lukyanov" <lav <at> netis.ru>
Cc: 1260-done <at> debbugs.gnu.org
Subject: Re: bug#1260: regex.c and RE_FRUGAL
Date: Tue, 28 Oct 2008 10:31:29 -0400

>> > This bug report is not quite for emacs, but for its regex library.
>> > It features RE_FRUGAL flag (very useful), but it does not seem to work.
>> > I have tried this rather simple program and it prints 0-12 instead of
>> > expected 0-6.
>> 
>> IIRC you'll need to set RE_NO_POSIX_BACKTRACKING as well, otherwise the
>> match returned will always be the longest.

> Thank you! The flag RE_NO_POSIX_BACKTRACKING did the trick.

> Is there a reason for RE_SYNTAX_EMACS including RE_FRUGAL and not including
> RE_NO_POSIX_BACKTRACKING?

Emacs passes RE_NO_POSIX_BACKTRACKING explicitly depending on whether it
wants posix behavior or not (it has matching functions like
"string-match" and "posix-string-match").


        Stefan

bug archived. Request was from Debbugs Internal Request <don <at> donarmstrong.com> to internal_control <at> emacsbugs.donarmstrong.com. (Tue, 25 Nov 2008 15:24:04 GMT) Full text and rfc822 format available.

This bug report was last modified 16 years and 303 days ago.

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GNU bug report logs - #1260 regex.c and RE_FRUGAL

GNU bug report logs - #1260
regex.c and RE_FRUGAL