Re: [GENERAL] Empty arrays with ARRAY[]

"Brendan Jurd" <direvus(at)gmail(dot)com> writes:
> This approach is making sense to me, but I've run into a bit of a
> dependency issue. A_Const does indeed have a slot for typecasts by
> way of a TypeName member. A_Const and TypeName are both defined in
> parsenodes.h, whereas ArrayExpr is defined in primnodes.h. So
> unfortunately I can't just add a TypeName member to ArrayExpr.

That would be quite the wrong thing to do anyway, since ArrayExpr is
a run-time representation and shouldn't have any such thing attached
to it. What you probably need is a separate parse-time representation
of ARRAY[], a la the difference between A_Const and Const.

Another possibility is to just hack up a private communication path
between transformExpr and transformArrayExpr, ie when you see TypeCast
check to see if its argument is ArrayExpr and do something different.
This would be a mite klugy but it'd be a much smaller patch that way.

regards, tom lane