Re: UNICODE characters above 0x10000

Dennis Bjorklund <db@zigo.dhs.org> writes:
> ... This also means that the start byte can never start with 7 or 8
> ones, that is illegal and should be tested for and rejected. So the
> longest utf-8 sequence is 6 bytes (and the longest character needs 4
> bytes (or 31 bits)).

Tatsuo would know more about this than me, but it looks from here like
our coding was originally designed to support only 16-bit-wide internal
characters (ie, 16-bit pg_wchar datatype width).  I believe that the
regex library limitation here is gone, and that as far as that library
is concerned we could assume a 32-bit internal character width.  The
question at hand is whether we can support 32-bit characters or not ---
and if not, what's the next bug to fix?

            regards, tom lane