[debbugs-tracker] bug#34100: closed (26.1; Incomplete ? and ?? handling in rx)

[GNU bug Tracking System]

Your message dated Fri, 01 Feb 2019 11:44:20 +0200
with message-id <address@hidden>
and subject line Re: bug#34100: Acknowledgement (26.1; Incomplete ? and ?? 
handling in rx)
has caused the debbugs.gnu.org bug report #34100,
regarding 26.1; Incomplete ? and ?? handling in rx
to be marked as done.

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-- 
34100: http://debbugs.gnu.org/cgi/bugreport.cgi?bug=34100
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> --- Begin Message ---
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>
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> Subject: 
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> 26.1; Incomplete ? and ?? handling in rx
>
>
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> Date: 
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> Wed, 16 Jan 2019 12:39:58 +0100
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>
> In rx, the ? and ?? operators can be written verbatim as ? and ?? (space and ? 
> character), or by using symbols whose leading character needs to be escaped, \? 
> and \?? respectively. The names come from Olin Shivers's SRE, but ? is not a 
> special character in Scheme syntax, hence the character syntax hack.
>
> However, the symbols only partially work:
>
> (rx (\? "x") (\?? "y"))       --> "x?y?"  ; expected "x?y??"
> (rx (minimal-match (\? "x"))) --> "x??"   ; expected "x?"
>
> While it could be argued that only the character-based syntax should be used, 
> the fact is that the symbols are accepted and seem to work, just in a subtly 
> broken way.
>
> The documentation is also not clear on this point, and a programmer knowing the 
> elisp syntax might very well assume that the symbols are the ones to use.
>
> Suggested fix:
>
> diff --git a/lisp/emacs-lisp/rx.el b/lisp/emacs-lisp/rx.el
> index a39fe55c32..8b4551d0d3 100644
> --- a/lisp/emacs-lisp/rx.el
> +++ b/lisp/emacs-lisp/rx.el
> @@ -733,8 +733,8 @@
>  is non-nil."
>    (rx-check form)
>    (setq form (rx-trans-forms form))
> -  (let ((suffix (cond ((memq (car form) '(* + ?\s)) "")
> -                     ((memq (car form) '(*? +? ??)) "?")
> +  (let ((suffix (cond ((memq (car form) '(* + \? ?\s)) "")
> +                     ((memq (car form) '(*? +? \?? ??)) "?")
>                       (rx-greedy-flag "")
>                       (t "?")))
>         (op (cond ((memq (car form) '(* *? 0+ zero-or-more)) "*")
>
>
>
>
>
> --- End Message ---
> --- Begin Message ---
>
>
>
> Subject: 
>
> Re: bug#34100: Acknowledgement (26.1; Incomplete ? and ?? handling in rx)
>
>
>
>
> Date: 
>
> Fri, 01 Feb 2019 11:44:20 +0200
>
>
>
>
> > From: Michael Heerdegen <address@hidden>
> > Date: Mon, 28 Jan 2019 16:53:28 +0100
> > Cc: address@hidden
> > 
> > Mattias Engdegård <address@hidden> writes:
> > 
> > > Anything more I can do? I thought this one would be rather
> > > straightforward.  I do understand that there are more pressing
> > > matters.
> > 
> > I guess you just have to be patient until someone has a look.  That can
> > sometimes take some time, there are a lot of open bug reports...
> > 
> > For me what you suggest looks like a good idea btw.
>
> Sorry for the long delay, Mattias.  I've now pushed your changes to
> the master branch, and I'm marking this bug done.
>
> Thanks.
>
>
> --- End Message ---