On Mon, Aug 5, 2013 at 1:31 AM, Robert Haas
<robertmhaas@gmail.com> wrote:
This looks like really nice work.
It does. It's functionally equivalent to my attempt but with much better comments and cleaner code.
But it doesn't seem to cover the case I was stumped on, namely "nulls first" appearing in a place where two unreserved keywords can appear consecutively. This doesn't happen for WITH_* before "with" is a reserved keyword.
Looking into it a bit I see that the case I was most worried about is actually a non-issue. We don't support column aliases without "AS" unless the alias is completely unknown to the parser. That seems a bit of a strange rule that must make the syntax with the missing AS pretty unreliable if people are looking for code that will continue to work in future versions. I never knew about this.
The only other case I could come up with in my regression tests is pretty esoteric:
CREATE COLLATION nulls (locale='C');
ALTER OPERATOR CLASS text_ops USING btree RENAME TO first;
CREATE TABLE nulls_first(t text);
CREATE INDEX nulls_first_i ON nulls_first(t COLLATE nulls first);
I'm not 100% sure there aren't other cases where this can occur though.
--
greg
