On Wed, 2025-12-17 at 11:39 +0100, Peter Eisentraut wrote:
> For Metaphone, I found the reference implementation linked from its
> Wikipedia page, and it looks like our implementation is pretty
> closely
> aligned to that. That reference implementation also contains the
> C-with-cedilla case explicitly. The correct fix here would probably
> be
> to change the implementation to work on wide characters. But I think
> for the moment you could try a shortcut like, use pg_ascii_toupper(),
> but if the encoding is LATIN1 (or LATIN9 or whichever other encodings
> also contain C-with-cedilla at that code point), then explicitly
> uppercase that one as well. This would preserve the existing
> behavior.
Done, attached new patches.
Interestingly, WIN1256 encodes only the SMALL LETTER C WITH CEDILLA. I
think, for the purposes here, we can still consider it to "uppercase"
to \xc7, so that it can still be treated as the same sound. Technically
I think that would be an improvement over the current code in this edge
case, and suggests that case folding would be a better approach than
uppercasing.
Regards,
Jeff Davis
