Re: range_adjacent and discrete ranges

Florian Pflug <fgp(at)phlo(dot)org> writes:
> ...This definition does not depend on any specific canonical form of ranges,
> only on the canonicalize function's ability to detect empty ranges.

Hmm, well, now that you mention it, I don't think the current canonical
functions handle empty ranges very nicely at all. They tend to spit up:

regression=# select int4range(4,4,'[]');
int4range
-----------
[4,5)
(1 row)

regression=# select int4range(4,4,'(]');
ERROR: range lower bound must be less than or equal to range upper bound
regression=# select int4range(4,4,'()');
ERROR: range lower bound must be less than or equal to range upper bound

Would it be better for them to silently transform such cases to "empty"?

regards, tom lane