Re: Help improve regular expression for 24 hours format

[Yuri Khan <yuri.v.khan@gmail.com>]

On Thu, 24 Nov 2022 at 10:38, Jean Louis <bugs@gnu.support> wrote:

> This regular expression shall match 24 hours format such as "12:34".
>
> I do not like how I wrote this regular expression, is there way to
> provide to `rx' function something like "[012]"?

I’d write it in classic regexp notation as

    \(?:\(?:[01][0-9]|2[0-3]\):\(?:[0-5][0-9]\)\)

and probably leave like that as it’s readable enough as is.

If you feel the need for rx here, then, as Tomas said, ‘any’ (aka ‘in’
and ‘char’) with ranges is your friend.

(Also I don’t understand your use of ‘(= 1 …)’. Looks redundant to me.)