On 2024-05-26 14:02, James Youngman wrote:
Is this a known issue? If yes, was there a decision not to implement this
in gnulib, or is it a to-do?
Gnulib (which is very close to glibc) has never gotten around to
implementing shy groups. It'd be a nice thing to add for both Gnulib and
glibc,
Findutils has a bug report about non-capturing ("shy") groups \(? in
Emacs-dialect regular expressions (
https://savannah.gnu.org/bugs/index.php?65770).
>From the Emacs Texinfo manual:
‘\(?: ... \)’
specifies a “shy group” that does not record the matched substring;
you can’t refer back
