From: tomas@tuxteam.de
To: steve-humphreys@gmx.com
Cc: "help-gnu-emacs@gnu.org" <help-gnu-emacs@gnu.org>
Subject: Re: [External] : Use the characters "+" and "-" in regular expressions
Date: Thu, 20 May 2021 12:22:44 +0200 [thread overview]
Message-ID: <20210520102244.GE1127@tuxteam.de> (raw)
In-Reply-To: <trinity-4405a98e-6f45-40c7-973f-3f47bfa65017-1621505509447@3c-app-mailcom-bs16>
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On Thu, May 20, 2021 at 12:11:49PM +0200, steve-humphreys@gmx.com wrote:
>
>
> > Sent: Thursday, May 20, 2021 at 9:56 PM
> > From: tomas@tuxteam.de
> > To: steve-humphreys@gmx.com
> > Cc: "help-gnu-emacs@gnu.org" <help-gnu-emacs@gnu.org>
> > Subject: Re: [External] : Use the characters "+" and "-" in regular expressions
> >
> > On Thu, May 20, 2021 at 11:42:58AM +0200, steve-humphreys@gmx.com wrote:
> > > I have now used ";; [;+-.]+" to match some specific lines.
> > >
> > > (string-match ";; [;+-.]+" s")
> > ^ NOOOO!
> >
> > This is a dash in the middle, indicating a range (i.e. "match all
> > characters in the range "+" to "."). In ASCII (and by extension,
> > in UTF-8), these are "+", ",", "-" and ".".
>
> I thought it was only about numeric and letter ranges only.
No. Any characters can be the endpoints of a range. But this is
somewhat dangerous, since, strictly speaking, the results might
depend on the character encoding. Nowadays, with ubiquitous Unicode,
this is less of a problem. In the context of Emacs, which probably
always uses its internal set (a superset of Unicode), results are
probably always consistent.
That doesn't mean they are always intuitive. Quick: is "d" in
the range "[(-{]"?
Don't do that. Your reader will thank you.
Again: please, play with it. Make yourself test cases.
Cheers
- t
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next prev parent reply other threads:[~2021-05-20 10:22 UTC|newest]
Thread overview: 50+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-19 16:07 Use the characters "+" and "-" in regular expressions steve-humphreys
2021-05-19 16:17 ` Skip Montanaro
2021-05-19 16:26 ` steve-humphreys
2021-05-19 16:47 ` Yuri Khan
2021-05-19 17:39 ` steve-humphreys
2021-05-19 19:16 ` tomas
2021-05-19 19:27 ` tomas
2021-05-19 19:30 ` Yuri Khan
2021-05-19 21:32 ` tomas
2021-05-19 21:59 ` [External] : " Drew Adams
2021-05-20 6:26 ` RE: [External] : " steve-humphreys
2021-05-20 7:59 ` steve-humphreys
2021-05-20 8:26 ` tomas
2021-05-20 8:41 ` steve-humphreys
2021-05-20 9:42 ` steve-humphreys
2021-05-20 9:56 ` tomas
2021-05-20 10:11 ` steve-humphreys
2021-05-20 10:22 ` tomas [this message]
2021-05-20 10:37 ` steve-humphreys
2021-05-20 10:50 ` tomas
2021-05-20 11:19 ` steve-humphreys
2021-05-20 11:27 ` steve-humphreys
2021-05-20 12:04 ` tomas
2021-05-20 11:31 ` Christopher Dimech
2021-05-20 11:40 ` steve-humphreys
2021-05-20 11:49 ` Christopher Dimech
2021-05-20 13:03 ` Jean Louis
2021-05-20 11:59 ` tomas
2021-05-20 12:53 ` Jean Louis
2021-05-20 12:46 ` Jean Louis
2021-05-20 13:55 ` steve-humphreys
2021-05-20 14:14 ` Jean Louis
2021-05-20 14:28 ` steve-humphreys
2021-05-20 16:24 ` Yuri Khan
2021-05-20 16:34 ` steve-humphreys
2021-05-20 17:16 ` Eduardo Ochs
2021-05-20 18:29 ` Drew Adams
2021-05-21 5:48 ` Jean Louis
2021-05-20 10:29 ` Negating a regexp Yuri Khan
2021-05-20 10:39 ` tomas
2021-05-20 12:39 ` [External] : Use the characters "+" and "-" in regular expressions Jean Louis
2021-05-20 7:15 ` Dash in regexp character classes: Beginnig vs. end [was: Use the characters "+" and "-" in regular expressions] tomas
2021-05-20 8:08 ` Robert Pluim
2021-05-19 19:26 ` [External] : Re: Use the characters "+" and "-" in regular expressions Drew Adams
2021-05-19 19:25 ` Drew Adams
2021-05-19 16:27 ` tomas
2021-05-19 16:39 ` Skip Montanaro
2021-05-19 17:43 ` Marcin Borkowski
2021-05-19 19:10 ` tomas
2021-05-19 19:17 ` [External] : " Drew Adams
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