Robert Haas <robertmhaas@gmail.com> writes:
> On Fri, Sep 11, 2009 at 5:32 PM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
>> Why? �We'd certainly still support the old syntax for existing options,
>> just as we did with EXPLAIN.
> None of the syntax proposals upthread had that property, which doesn't
> mean we can't do it. However, we'd need some way to differentiate the
> old syntax from the new one. I guess we could throw an unnecessary set
> of parentheses around the option list (blech), but you have to be able
> to tell from the first token which kind of list you're reading if you
> want to support both sets of syntax.
No, you just have to be able to tell it before the first difference in
grammar reduction path. If we did the syntax as keyword = value, for
instance, I believe the first equal sign would be a sufficient cue for
bison.
Not that parentheses would be such a terrible thing, especially if your
thoughts are leaning towards making COPY-embedded-in-SELECT be special
syntax rather than trying to force it into SRF syntax.
regards, tom lane