Horton

Re: Add CASEFOLD() function.

Vik Fearing <vik@postgresfriends.org>

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From: Vik Fearing <vik@postgresfriends.org>
To: Peter Eisentraut <peter@eisentraut.org>, Jeff Davis <pgsql@j-davis.com>, Joe Conway <mail@joeconway.com>, Ian Lawrence Barwick <barwick@gmail.com>
Cc: pgsql-hackers@postgresql.org
Date: 2025-06-19T16:21:09Z
Lists: pgsql-hackers

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →

  1. Fix PDF doc build.

  2. Add SQL function CASEFOLD().

  3. Add support for Unicode case folding.

On 19/06/2025 16:47, Peter Eisentraut wrote:
> On 17.06.25 17:37, Vik Fearing wrote:
>> For <fold> (which includes LOWER() and UPPER()), the text says in 
>> Section 6.35 GR 7.e:
>>
>>
>> If the character set of <character factor> is UTF8, UTF16, or UTF32, 
>> then FR is replaced by
>>      Case:
>>          i) If the <search condition> S IS NORMALIZED evaluates to 
>> True, then NORMALIZE (FR)
>>          ii) Otherwise, FR.
>>
>>
>> Here, FR is the result of the function and S is its argument.
>>
>>
>> It does not appear to me that our LOWER and UPPER functions obey this 
>> rule, so there is a valid argument that we should continue to ignore 
>> it. Or, we can say that we have at least one of three compliant.
>
> The SQL standard also says in a few other places that normalization 
> should be applied, and we do none of those, so this is probably not a 
> reason to change CASEFOLD at this point.
>

Works for me.

-- 

Vik Fearing.