[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
bug#2881: 23.0.91; inconsistent regexps with "explicitly numbered group
From: |
Joe Corneli |
Subject: |
bug#2881: 23.0.91; inconsistent regexps with "explicitly numbered group" |
Date: |
Fri, 3 Apr 2009 17:38:30 -0400 |
Oh, OK, I see! Never mind!
On Fri, Apr 3, 2009 at 5:32 PM, Andreas Schwab <schwab@linux-m68k.org> wrote:
> Andreas Schwab <schwab@linux-m68k.org> writes:
>
>> Joe Corneli <holtzermann17@gmail.com> writes:
>>
>>> Please execute the following forms with C-x C-e. Form 1
>>> and Form 3 return `t' (Yes, we are looking at the
>>> indicated regular expression), whereas Form 2 returns
>>> `nil' (even though from the Elisp reference page "34.3.1.3
>>> Backslash Constructs in Regular Expressions", it appears
>>> that this form ought to return `t' like the others).
>>
>> `\|' applies to the largest possible surrounding expressions.
>> Only a surrounding `\( ... \)' grouping can limit the grouping
>> power of `\|'.
>>
>>> (let ((possible-environments
>>> "\\(?1:lisp\\)\\|\\(?1:idea\\)\\|\\(?1:common\\)") )
>>> (looking-at
>>> (concat "\n*?\\\\begin{"
>>> possible-environments
>>> "}")))
>>
>>
>> The three alternatives of this regexp are "\n*?\\\\begin{\\(?1:lisp\\)",
>> "\\(?1:idea\\)" and "\\(?1:common\\)".
>
> The last one is "\\(?1:common\\)}", of course.
>
> Andreas.
>
> --
> Andreas Schwab, schwab@linux-m68k.org
> GPG Key fingerprint = 58CA 54C7 6D53 942B 1756 01D3 44D5 214B 8276 4ED5
> "And now for something completely different."
>