Re: Request for Patch Feedback: Lag & Lead Window Functions Can Ignore Nulls

Nicholas White escribió:

> For the parsing changes, it seems I can either make RESPECT and IGNORE
> reserved keywords, or add a lookahead to construct synthetic RESPECT NULLS
> and IGNORE NULLS keywords. The grammar wouldn't compile if RESPECT and
> IGNORE were just normal unreserved keywords due to ambiguities after a
> function definition (e.g. select abs(1) respect; - which is currently a
> valid statement).

Well, making them reserved keywords is not that great, so maybe the
lookahead thingy is better.  However, this patch introduces the third
and fourth uses of the "save the lookahead token" pattern in the
"default" switch cases.  Can we refactor that bit somehow, to avoid so
many duplicates?  (For a minute I thought that Andrew Gierth's WITH
ORDINALITY patch would add another one, but it seems not.)

-- 
Álvaro Herrera                http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Training & Services