Re: plpgsql - DECLARE - cannot to use %TYPE or %ROWTYPE for composite types

On 03/03/2016 05:45 AM, Pavel Stehule wrote:
> 2016-02-24 22:18 GMT+01:00 Peter Eisentraut <peter_e(at)gmx(dot)net
> <mailto:peter_e(at)gmx(dot)net>>:
>
> On 1/18/16 4:21 PM, Robert Haas wrote:
> > One idea that occurs to me is: If you can DECLARE BAR FOO%TYPE, but
> > then you want to make BAR an array of that type rather than a scalar,
> > why not write that as DECLARE BAR FOO%TYPE[]? That seems quite
> > natural to me.
>
> Right, and it's arguably dubious that that doesn't already work.
> Unfortunately, these % things are just random plpgsql parser hacks, not
> real types. Maybe this should be done in the main PostgreSQL parser
> with parameter hooks, if we wanted this feature to be available outside
> plpgsql as well.
>
> > I think the part of this patch that makes %TYPE work for more kinds of
> > types is probably a good idea, although I haven't carefully studied
> > exactly what it does.
>
> I agree that this should be more general. For instance, this patch
> would allow you to get the element type of an array-typed variable, but
> there is no way to get the element type of just another type. If we
> could do something like
>
> DECLARE
> var ELEMENT OF point;
>
> (not necessary that syntax)
>
> then
>
> DECLARE
> var ELEMENT OF othervar%TYPE;
>
> should just fall into place.
>
> I am sending update of this patch. The basic concept is same, syntax was
> changed per your and Robert requirement.

This new version of the patch was posted after the commitfest item was
marked ready for committer. Does anyone have further comments or
objections to the concept or syntax before I try to take this forward?

Thanks,

Joe

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