From: Paul Eggert <eggert@cs.ucla.edu>
To: demerphq <demerphq@gmail.com>
Cc: Philip.Hazel@gmail.com, 60690@debbugs.gnu.org,
"mega lith01" <megalith01@gmail.com>,
"Carlo Arenas" <carenas@gmail.com>,
"Ævar Arnfjörð Bjarmason" <avarab@gmail.com>,
"Junio C Hamano" <gitster@pobox.com>,
pcre-dev@exim.org, "Tukusej’s Sirs" <tukusejssirs@protonmail.com>,
git@vger.kernel.org
Subject: Re: bug#60690: -P '\d' in GNU and git grep
Date: Fri, 7 Apr 2023 09:48:40 -0700 [thread overview]
Message-ID: <767d3617-e35a-a693-6ec8-f65421c68e5f@cs.ucla.edu> (raw)
In-Reply-To: <CANgJU+XoyptS8NU+f6uMLrKjQakv=iN2c4DQydVaBVH3dK3s-w@mail.gmail.com>
On 2023-04-06 08:45, demerphq wrote:
>> Although this causes pcre2grep to mishandle Unicode characters:
>>
>> $ echo 'Ævar' | pcre2grep '[Ssß]'
>> Ævar
>>
>> it mimics Perl 5.36:
>>
>> $ echo 'Ævar' | perl -ne 'print $_ if /[Ssß]/'
>> Ævar
>>
>> so this seems to be what Perl users expect, despite its infelicities.
> Actually no, I think you have misunderstood what is happening at the
> different layers involved here.
No, I understood what was going on. My point was that Perl users seem to
have accepted this behavior, even though it does not match what people
would ordinarily expect.
> What you should have done is something like this:
No, for two reasons. First, I'm no Perl expert and so I don't know (and
don't particularly want to learn) its complicated Unicode options and
calls. Second, /[Ss\x{DF}]/u is hard to read. If I want the S letters of
traditional German, I'll write them in the obvious way, as [Ssß]. No
doubt Perl will let me do this somehow - but it is telling that none of
your examples do it in such a straightforward way.
> $ echo 'Ævar' | perl -ne 'utf8::decode($_); print $_ if /[Ss\x{DF}]/u'
> $ echo 'baß' | perl -MEncode -ne 'utf8::decode($_); print
> encode_utf8($_) if /[Ss\x{DF}]/u'
> baß
> $ echo 'Ævar' | perl -MEncode -ne 'utf8::decode($_); print
> encode_utf8($_) if /[Ss\x{C6}]/u'
> Ævar
> $ echo 'Ævar' | perl -MEncode -ne 'utf8::decode($_); print
> encode_utf8($_) if /[Ss\x{e6}]/ui'
> Ævar
next prev parent reply other threads:[~2023-04-07 16:49 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-01-08 6:23 [PATCH] grep: correctly identify utf-8 characters with \{b,w} in -P Carlo Marcelo Arenas Belón
2023-01-08 6:39 ` Junio C Hamano
2023-01-08 15:52 ` [PATCH v2] " Carlo Marcelo Arenas Belón
2023-01-09 11:35 ` Ævar Arnfjörð Bjarmason
2023-01-09 18:40 ` bug#60690: [PATCH v2] grep: correctly identify utf-8 characters with \{b, w} " Paul Eggert
2023-01-09 19:51 ` Ævar Arnfjörð Bjarmason
2023-01-09 23:12 ` Paul Eggert
2023-01-10 4:49 ` [PATCH v2] grep: correctly identify utf-8 characters with \{b,w} " Carlo Arenas
2023-01-16 20:48 ` Junio C Hamano
2023-04-03 21:38 ` -P '\d' in GNU and git grep Paul Eggert
2023-04-04 3:30 ` bug#60690: " Jim Meyering
2023-04-04 6:46 ` Paul Eggert
2023-04-04 15:31 ` Jim Meyering
2023-04-04 6:56 ` Carlo Arenas
2023-04-04 18:25 ` bug#60690: " Paul Eggert
2023-04-04 19:31 ` Junio C Hamano
2023-04-05 18:32 ` Paul Eggert
2023-04-05 19:04 ` Paul Eggert
2023-04-05 19:37 ` Junio C Hamano
2023-04-05 19:40 ` Jim Meyering
2023-04-05 20:03 ` Paul Eggert
2023-04-05 21:20 ` Carlo Arenas
2023-04-06 15:45 ` demerphq
2023-04-07 16:48 ` Paul Eggert [this message]
2023-04-06 13:39 ` demerphq
2023-04-07 19:00 ` Paul Eggert
2023-04-08 5:01 ` Carlo Arenas
2023-04-08 22:45 ` Paul Eggert
2023-01-17 10:51 ` [PATCH v3] grep: correctly identify utf-8 characters with \{b,w} in -P Carlo Marcelo Arenas Belón
2023-01-17 12:38 ` Ævar Arnfjörð Bjarmason
2023-01-17 15:19 ` Junio C Hamano
2023-01-18 7:35 ` Carlo Arenas
2023-01-18 11:49 ` Ævar Arnfjörð Bjarmason
2023-01-18 16:20 ` Junio C Hamano
2023-01-18 23:06 ` Ævar Arnfjörð Bjarmason
2023-01-18 23:24 ` Junio C Hamano
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