On 14.03.24 12:25, Andrey M. Borodin wrote:
I think the behavior of uuid_extract_var(iant) is wrong. The code
takes just two bits to return, but the draft document is quite clear
that the variant is 4 bits (see Table 1).
Well, it was correct only for implemented variant. I've made version that
implements full table 1 from section 4.1.
I think we are still interpreting this differently. I think uuid_extract_variant should
just return whatever is in those four bits. Your function comment says "Can return
only 0, 0b10, 0b110 and 0b111.", which I don't think it is correct. It should
return 0 through 15.
We will return "do not care" bits. This bits can confuse someone. E.g. for
varaint 0b10 we can return 8, 9, 10 and 11 randomly. Is it OK? BTW for some reason
document lists number 1-15, but your are correct that range is 0-15.
I agree it's confusing. Before I studied the RFC 4122bis project, I
didn't even know about variant vs. version. I think overall people will
find this more confusing than useful. If you just want to know, "is
this UUID of the kind specified in RFC 4122", you can query it with
uuid_extract_version(x) IS NOT NULL. So maybe we don't need the
_extract_variant function?
