[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
RE: test for shy-group "feature"?
From: |
Drew Adams |
Subject: |
RE: test for shy-group "feature"? |
Date: |
Fri, 9 Dec 2005 19:42:18 -0800 |
> Emacs 22 has shy groups for regexps; previous versions did not.
Wrong.
** Regular expressions now support intervals \{n,m\} as well as
Perl's shy-groups \(?:...\) and non-greedy *? +? and ?? operators.
Also back-references like \2 are now considered as an error if the
corresponding subgroup does not exist (or is not closed yet).
Previously it would have been silently turned into `2'
(ignoring the `\').
I didn't find any reference to "shy" by grepping the source code. Thanks for
looking in News.
> When writing conditional code that tries to work with multiple Emacs
> versions, it is usually better to test fboundp, boundp, or
> featurep, than it
> is to test the major version. I couldn't find any function,
> variable, or
> feature associated with this new "feature", shy groups. Is
> there one that I
> might have missed? Thanks.
(if (string-match "\\(?:\\)" "")
...
...)
Very good (elegant - it even acts as an explanatory comment).
Thanks.