Re: Mention column name in error messages

On Wed, Jul 1, 2015 at 12:30 AM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
>
> What seems more likely to lead to a usable patch is to arrange for the
> extra information you want to be emitted as error "context", via an error
> context callback that gets installed at the right times. ...
> ...
> with no need for int8in to be directly aware of the context. You should
> try adapting that methodology for the cases you're worried about.
>

Hi Tom (and others),

Sorry it took so long for me to follow up on this, hopefully I found a
couple
a hours today to try writing another patch.

In any case, thanks for reviewing my first attempt and taking time to write
such a detailed critique... I've learned a lot!

I am now using the error context callback stack. The current column name
and column type are passed to the callback packed inside a new structure
of type "TransformExprState".
Those information are then passed to `errhint` and will be presented to the
user later on (in case of coercion failure).

Please find the WIP patch attached.
(I've pushed the patch on my GH fork[1] too).

Thanks again,
Franck

[1]:
https://github.com/franckverrot/postgres/commit/73dd2cd096c91cee1b501d5f94ba81037de30fd1