Re: BUG #7999: Regexp with utf8

somloieater(at)gmail(dot)com writes:
> PostgreSQL version: 9.1.8

> I've checked with a few other characters which are >1byte in utf8. U+00F0
> counds as \w, but nothing I've tried > FF matches. I wonder if it's
> something to do with >256?

Yup. This is partially resolved in PG 9.2, but will never be fixed in
older branches. From the commit log:

Also, remove the hard-wired limitation to not consider wctype.h results for
character codes above 255. It turns out that we can't push the limit as
far up as I'd originally hoped, because the regex colormap code is not
efficient enough to cope very well with character classes containing many
thousand letters, which a Unicode locale is entirely capable of producing.
Still, we can push it up to U+7FF (which I chose as the limit of 2-byte
UTF8 characters), which will at least make Eastern Europeans happy pending
a better solution. Thus, this commit resolves the specific complaint in
bug #6457, but not the more general issue that letters of non-western
alphabets are mostly not recognized as matching [[:alpha:]].

regards, tom lane