Re: [Perl/perl5] 502da7: make /p a no-op

On my phone so forgive the double reply. The code i mean is something like
this:

while (<>) {
  while (/(.)/g) { $count++}
}

Try that on a large file. If it appears to hang then /p should not be
removed.

Yves

perl -Mre=debug -e "/just|another|perl|hacker/"

On Thu, 12 Feb 2026, 17:56 demerphq, <[email protected]> wrote:

> You sure this doesn't make while /g matches go quadratic? Lastly I checked
> /p still matters for while/g -- the COW stuff doesn't always kick in: Not
> every string can be COWed. Iirc strings returned from <>/readline aren't
> COWed.
>
> Every time people proposed removing /p when I have  checked while /g it
> has been broken.
>
> Yves
>
> Yves
>
> ---
> perl -Mre=debug -e "/just|another|perl|hacker/"
>
> On Thu, 12 Feb 2026, 16:39 Philippe Bruhat (BooK) via perl5-changes, <
> [email protected]> wrote:
>
>>   Branch: refs/heads/book/p-modifier-is-a-noop
>>   Home:   https://github.com/Perl/perl5
>>   Commit: 502da7e0422c94f36fda5e70416c4f92adca225e
>>
>> https://github.com/Perl/perl5/commit/502da7e0422c94f36fda5e70416c4f92adca225e
>>   Author: Philippe Bruhat (BooK) <[email protected]>
>>   Date:   2026-02-12 (Thu, 12 Feb 2026)
>>
>>   Changed paths:
>>     M regexec.c
>>     M t/re/reg_pmod.t
>>
>>   Log Message:
>>   -----------
>>   make /p a no-op
>>
>> meaning that a copy of the matched string is always preserved,
>> regardless of usage of the /p modifier
>>
>> Closes GH #24147
>>
>>
>>   Commit: 38f00a1fb6754d42ee8282106fa99bf51defc263
>>
>> https://github.com/Perl/perl5/commit/38f00a1fb6754d42ee8282106fa99bf51defc263
>>   Author: Philippe Bruhat (BooK) <[email protected]>
>>   Date:   2026-02-12 (Thu, 12 Feb 2026)
>>
>>   Changed paths:
>>     M pod/perlreref.pod
>>     M pod/perlvar.pod
>>
>>   Log Message:
>>   -----------
>>   document the new behaviour of /p
>>
>>
>>   Commit: 432b96a3328e773407f8c31a9fd224b3b0606f1a
>>
>> https://github.com/Perl/perl5/commit/432b96a3328e773407f8c31a9fd224b3b0606f1a
>>   Author: Philippe Bruhat (BooK) <[email protected]>
>>   Date:   2026-02-12 (Thu, 12 Feb 2026)
>>
>>   Changed paths:
>>     M pod/perldelta.pod
>>
>>   Log Message:
>>   -----------
>>   perldelta entry about the neutering of /p
>>
>>
>> Compare:
>> https://github.com/Perl/perl5/compare/bc4893f14393...432b96a3328e
>>
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>