Re: simplify regular expression locale global variables

On 15.10.24 17:04, Tom Lane wrote:
> Peter Eisentraut <peter(at)eisentraut(dot)org> writes:
>> but after the recent improvements to pg_locale_t handling, we don't need
>> all three anymore. All the information we have is contained in
>> pg_locale_t, so we just need to keep that one. This allows us to
>> structure the locale-using regular expression code more similar to other
>> locale-using code, mainly by provider, avoiding another layer that is
>> specific only to the regular expression code. The first patch
>> implements that.
>
> I didn't read that patch in detail; somebody who's more familiar than
> I with the recent locale-code changes ought to read it and confirm
> that no subtle behavioral changes are sneaking in. But +1 for
> concept.

Ok, I'll wait for someone to give it a detailed review.

>
>> The second patch removes a call to pg_set_regex_collation() that I think
>> is unnecessary.
>
> I think this is actively wrong. pg_regprefix is engaged in> determining whether there's a fixed prefix of the regex, which
> at least involves a sort of symbolic execution. As an example,
> whether '^x' has a fixed prefix surely depends on whether the locale
> is case-insensitive.

Hmm, okay, I'll leave this out for now and maybe come back to it later.
For the time being, here is a new patch with this part omitted.