Re: [PATCH] Exorcise "zero-dimensional" arrays (Was: Re: Should array_length() Return NULL)

On 26 March 2013 22:57, Robert Haas <robertmhaas(at)gmail(dot)com> wrote:
> They hate it twice as much when the change is essentially cosmetic.
> There's no functional problems with arrays as they exist today that
> this change would solve.
>

We can't sensibly test for whether an array is empty. I'd call that a
functional problem.

The NULL return from array_{length,lower,upper,ndims} is those
functions' way of saying their arguments failed a sanity check. So we
cannot distinguish in a disciplined way between a valid, empty array,
and bad arguments. If the zero-D implementation had been more
polished and say, array_ndims returned zero, we had provided an
array_empty function, or the existing functions threw errors for silly
arguments instead of returning NULL, then I'd be more inclined to see
your point. But as it stands, the zero-D implementation has always
been half-baked and slightly broken, we just got used to working
around it.

Cheers,
BJ