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Re: Help improve regular expression for 24 hours format
From: |
Jean Louis |
Subject: |
Re: Help improve regular expression for 24 hours format |
Date: |
Thu, 24 Nov 2022 11:59:20 +0300 |
User-agent: |
Mutt/2.2.7+37 (a90f69b) (2022-09-02) |
* Yuri Khan <yuri.v.khan@gmail.com> [2022-11-24 09:33]:
> 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.)
Thanks, I make it now this way:
(defvar rcd-rx-time (rx line-start (or "00" "01" "02" "03" "04" "05" "06" "07"
"08" "09" "10" "11"
"12" "13" "14" "15" "16" "17" "18" "19"
"20" "21" "22" "23")
":" (any "0" "1" "2" "3" "4" "5") (any digit)
line-end)
"Regular expression for 24 hours format")
➜ "^\\(?:0[0-9]\\|1[0-9]\\|2[0-3]\\):[0-5][[:digit:]]$"
I like to have `rx' notation, and it still looks way complicated.
(string-match rcd-rx-time "00:00") ➜ 0
(string-match rcd-rx-time "30:00") ➜ nil
(string-match rcd-rx-time "24:00") ➜ nil
(string-match rcd-rx-time "23:69") ➜ nil
(string-match rcd-rx-time "23:59") ➜ 0
--
Jean
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- Help improve regular expression for 24 hours format, Jean Louis, 2022/11/23
- Re: Help improve regular expression for 24 hours format, tomas, 2022/11/24
- Re: Help improve regular expression for 24 hours format, Yuri Khan, 2022/11/24
- Re: Help improve regular expression for 24 hours format,
Jean Louis <=
- Re: Help improve regular expression for 24 hours format, tomas, 2022/11/24
- Re: Help improve regular expression for 24 hours format, Jean Louis, 2022/11/24
- Re: Help improve regular expression for 24 hours format, tomas, 2022/11/24
- [SOLVED]: Re: Help improve regular expression for 24 hours format, Jean Louis, 2022/11/24
- [SOLVED]: Re: Help improve regular expression for 24 hours format, Jean Louis, 2022/11/24
- Re: [SOLVED]: Re: Help improve regular expression for 24 hours format, Emanuel Berg, 2022/11/26
- Re: [SOLVED]: Re: Help improve regular expression for 24 hours format, Jean Louis, 2022/11/26
Re: Help improve regular expression for 24 hours format, Michael Heerdegen, 2022/11/24