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From: Dominique Devienne <ddevienne@gmail.com>
Date: Fri, 12 Sep 2025 15:57:45 +0200
Message-ID: <CAFCRh-9KdBrOHcdCddQGWi_wFSWD=Hmr9VG61YoJ2AkzahnaKQ@mail.gmail.com>
Subject: Re: Latest patches break one of our unit-test, related to RLS
To: jian he <jian.universality@gmail.com>
Cc: Laurenz Albe <laurenz.albe@cybertec.at>, pgsql-general@postgresql.org
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On Fri, Sep 12, 2025 at 3:54=E2=80=AFPM jian he <jian.universality@gmail.co=
m> wrote:
> > > select v from t where v similar to 'foo[\d\w]_%';
> > > select v from t where v similar to 'foo[[[:digit:]][[:word:]]]_%';

> The above two examples are the same, per
> (Table 9.21. Regular Expression Class-Shorthand Escapes)

Of course.

> my guess why 'foo0bar' will fail for 'foo[[[:digit:]][[:word:]]]_%';
> 1. process character 0, it does meet [[:digits]] character class.
> 2. process character b, it does not meet [[:digits]], then fails,
> it won't check again whether character b is satisfied with [[:word:]] or =
not.

Then you don't know what [...] means in regexes I'm afraid. --DD