Re: New CORRESPONDING clause design

2017-03-18 18:32 GMT+01:00 Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>:

> Pavel Stehule <pavel(dot)stehule(at)gmail(dot)com> writes:
> > 2017-03-18 17:50 GMT+01:00 Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>:
> >> I'm not impressed by using A_Const for the members of the CORRESPONDING
> >> name list. That's not a clever solution, that's a confusing kluge,
> >> because it's a complete violation of the meaning of A_Const. Elsewhere
> >> we just use lists of String for name lists, and that seems sufficient
> >> here. Personally I'd just use the existing columnList production rather
> >> than rolling your own.
>
> > The reason was attach a location to name for more descriptive error
> > message.
>
> [ shrug... ] The patch fails to actually use the location anywhere.
> If it had, you might have noticed that it's attaching the wrong location
> to all elements except the first :-(. So I'm not very excited about that.
> I definitely don't see a reason for CORRESPONDING to track locations of
> name list elements when no other name list productions do. It might be
> worth proposing a followon patch to change all of them (perhaps by adding
> a location field to struct "Value") and then make use of the locations in
> error messages more widely.
>

I had a idea use own node for CORRESPONDING with location - and using this
location in related error messages.

What do you think about it?

Regards

Pavel

>
> regards, tom lane
>