From: "Mattias Engdegård" <mattiase@acm.org>
To: Paul Eggert <eggert@cs.ucla.edu>
Cc: Stephen Leake <stephen_leake@stephe-leake.org>,
emacs-devel <emacs-devel@gnu.org>
Subject: Re: :alnum: broken?
Date: Sun, 23 Feb 2020 11:21:58 +0100 [thread overview]
Message-ID: <D3840F98-A930-40C7-8F05-88D9D16CF36F@acm.org> (raw)
In-Reply-To: <5fecc0e1-1ee2-5a89-9297-b0b9aa4a8e9c@cs.ucla.edu>
22 feb. 2020 kl. 02.09 skrev Paul Eggert <eggert@cs.ucla.edu>:
> That is, GNU grep treats a bracket expression like '[:space:]' as an error, since it's inevitably a typo. (POSIX does not allow this behavior so the diagnostic is suppressed if POSIXLY_CORRECT is set.)
Such a check is obviously unsound, strictly speaking, which may be a reason for objecting to it. But in practice? It would have to be naïve regexp-building code that puts characters inside square brackets without eliminating duplicates, like
(defun make-char-regexp (char-list)
(concat "[" (apply #'string char-list) "]"))
and given our experience in regexp mistakes, such code probably exists in use somewhere. I'm still in favour of the check since it would be cheap and helpful, and false positives unlikely. It is a fairly infrequent blunder, though.
next prev parent reply other threads:[~2020-02-23 10:21 UTC|newest]
Thread overview: 77+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-21 18:58 :alnum: broken? Stephen Leake
2020-02-21 19:00 ` Paul Eggert
2020-02-21 19:32 ` Mattias Engdegård
2020-02-21 21:28 ` Stephen Leake
2020-02-22 1:09 ` Paul Eggert
2020-02-22 7:48 ` Eli Zaretskii
2020-02-22 21:28 ` Paul Eggert
2020-02-23 3:28 ` Eli Zaretskii
2020-02-23 10:21 ` Mattias Engdegård [this message]
2020-02-23 18:13 ` Paul Eggert
2020-02-23 18:27 ` Eli Zaretskii
2020-02-23 19:34 ` Óscar Fuentes
2020-02-23 22:12 ` Drew Adams
2020-02-25 3:57 ` Richard Stallman
2020-02-25 14:37 ` Stefan Monnier
2020-02-25 15:45 ` Drew Adams
2020-02-25 15:40 ` Drew Adams
2020-02-25 9:33 ` Andreas Schwab
2020-02-25 13:53 ` Clément Pit-Claudel
2020-02-25 15:40 ` Drew Adams
2020-02-23 18:40 ` Mattias Engdegård
2020-02-26 14:10 ` Mattias Engdegård
2020-02-26 14:54 ` Drew Adams
2020-02-26 15:48 ` Stefan Monnier
2020-02-26 21:00 ` Paul Eggert
2020-02-26 21:18 ` Mattias Engdegård
2020-02-26 21:24 ` Clément Pit-Claudel
2020-02-26 22:01 ` Mattias Engdegård
2020-02-26 22:38 ` Eli Zaretskii
2020-02-27 17:57 ` Mattias Engdegård
2020-02-27 23:17 ` Óscar Fuentes
2020-02-28 8:09 ` Eli Zaretskii
2020-02-28 8:48 ` Paul Eggert
2020-02-28 13:11 ` Eli Zaretskii
2020-02-28 17:41 ` Paul Eggert
2020-02-28 20:09 ` Eli Zaretskii
2020-02-28 20:25 ` Paul Eggert
2020-02-28 20:38 ` Eli Zaretskii
2020-02-28 21:04 ` Mattias Engdegård
2020-02-28 21:40 ` Eli Zaretskii
2020-02-29 11:43 ` Mattias Engdegård
2020-02-29 12:07 ` Eli Zaretskii
2020-02-29 14:24 ` Stefan Monnier
2020-02-29 14:14 ` Stefan Monnier
2020-02-29 17:33 ` Óscar Fuentes
2020-02-29 19:52 ` Stefan Monnier
2020-02-29 21:12 ` Óscar Fuentes
2020-02-29 22:22 ` Marcin Borkowski
2020-02-29 22:34 ` Clément Pit-Claudel
2020-03-01 22:44 ` Marcin Borkowski
2020-03-02 3:07 ` Stefan Monnier
2020-03-02 7:15 ` Marcin Borkowski
2020-03-02 7:41 ` Emanuel Berg via Emacs development discussions.
2020-03-02 16:14 ` Drew Adams
2020-03-02 16:51 ` Emanuel Berg via Emacs development discussions.
2020-03-02 7:56 ` Joost Kremers
2020-03-02 9:44 ` Štěpán Němec
2020-03-02 10:43 ` Joost Kremers
2020-03-02 13:37 ` Clément Pit-Claudel
2020-03-02 17:03 ` Stefan Monnier
2020-03-02 18:23 ` Clément Pit-Claudel
2020-02-29 23:02 ` Andrea Corallo
2020-03-01 22:41 ` Marcin Borkowski
2020-02-29 22:58 ` Stefan Monnier
2020-02-29 23:28 ` Óscar Fuentes
2020-02-27 1:33 ` Paul Eggert
2020-02-26 16:01 ` Andreas Schwab
2020-02-26 21:06 ` Mattias Engdegård
2020-02-27 8:43 ` Andreas Schwab
2020-02-27 18:05 ` Mattias Engdegård
2020-02-22 9:09 ` Eli Zaretskii
2020-02-23 3:49 ` Richard Stallman
2020-02-23 7:51 ` Paul Eggert
2020-02-23 15:07 ` Eli Zaretskii
2020-02-21 19:01 ` Noam Postavsky
2020-02-21 19:04 ` Andreas Schwab
[not found] <<86wo8flqct.fsf@stephe-leake.org>
[not found] ` <<f89e340f-9a19-50e1-4421-57fd3e235548@cs.ucla.edu>
[not found] ` <<86sgj3ljf0.fsf@stephe-leake.org>
[not found] ` <<E1j5iGS-0000r6-Id@fencepost.gnu.org>
[not found] ` <<18bd2b64-1c2f-055f-4fa0-092bdb1da531@cs.ucla.edu>
[not found] ` <<838sktibpu.fsf@gnu.org>
2020-02-23 16:52 ` Drew Adams
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