Horton

Re: Built-in CTYPE provider

Jeff Davis <pgsql@j-davis.com>

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From: Jeff Davis <pgsql@j-davis.com>
To: Daniel Verite <daniel@manitou-mail.org>
Cc: pgsql-hackers@postgresql.org
Date: 2023-12-14T14:01:59Z
Lists: pgsql-hackers 
On Wed, 2023-12-13 at 16:34 +0100, Daniel Verite wrote:
> In particular "el" (modern greek) has case mapping rules that
> ICU seems to implement, but "el" is missing from the list
> ("lt", "tr", and "az") you identified.

I compared with glibc el_GR.UTF-8 and el_CY.UTF-8 locales, and the
ctype semantics match C.UTF-8 for all code points. glibc is not doing
this additional tailoring for "el".

Therefore I believe the builtin CTYPE would be very useful for case
mapping (both "simple" and "full") even without this additional
tailoring.

You are correct that ICU will still have some features that won't be
supported by the builtin provider. Better word boundary semantics in
INITCAP() are another advantage.

Regards,
	Jeff Davis

Commits

  1. Support PG_UNICODE_FAST locale in the builtin collation provider.

  2. Support Unicode full case mapping and conversion.

  3. Fix test failures when language environment is not UTF-8.

  4. Add unicode_strtitle() for Unicode Default Case Conversion.

  5. Use version for builtin collations.

  6. Fix convert_case(), introduced in 5c40364dd6.

  7. Inline basic UTF-8 functions.

  8. Support C.UTF-8 locale in the new builtin collation provider.

  9. Fix another warning, introduced by 846311051e.

  10. Address more review comments on commit 2d819a08a1.

  11. Fix unreachable code warning from commit 2d819a08a1.

  12. Introduce "builtin" collation provider.

  13. Catalog changes preparing for builtin collation provider.

  14. Unicode case mapping tables and functions.

  15. Add Unicode property tables.

  16. Documentation update for Standard Collations.

  17. Cleanup for unicode-update build target and test.

  18. Shrink Unicode category table.

  19. Make some error strings more generic

  20. pg_upgrade: copy locale and encoding information to new cluster.

  21. Update Unicode data to Unicode 15.0.0

  22. Create a new type category for "internal use" types.