On Fri, Jun 3, 2022 at 8:09 PM Bruno Haible <br...@clisp.org> wrote: > Paul Eggert asked: > > So, what do you think of the idea of not warning for this particular > > stray backslash? Proposed Gnulib patch attached, with the idea of > > propagating this into GNU grep before its upcoming release. I haven't > > installed this. > > Warning about undefined behaviour is good. > > But when I think about the thousands of people who use regular expressions > out there. How would they remember that in parentheses both should be > backslash-escaped in EREs > \( \) > but brackets and braces are asymmetric > \[ ] > \{ } > Even if the warning message you install in grep has 3 or 5 lines and goes > into all details, we are not serving the community if we force them to adhere > to asymmetric rules, where up to now they could use symmetric rules.
I agree with Bruno.