Re: Clobbered parameter names via DECLARE in PL/PgSQL

On 15 April 2012 18:54, Pavel Stehule <pavel.stehule@gmail.com> wrote:
> 2012/4/15 Brendan Jurd <direvus@gmail.com>:
>> Perhaps it's a failure of imagination on my part, but I can't think of
>> a legitimate reason for a programmer to deliberately use the same name
>> to refer to a declared variable and a function parameter.  What would
>> be the benefit?
>
> it depends on level of nesting blocks. For simple functions there
> parameter redeclaration is clean bug, but for more nested blocks and
> complex procedures, there should be interesting using some local
> variables with same identifier like some parameters and blocking
> parameter's identifier can be same unfriendly feature like RO
> parameters in previous pg versions.
>
> I understand your motivation well, but solution should be warning, not
> blocking. I think.

I can accept that ... but I wonder about the implementation of such a
warning.  Can we raise a WARNING message on CREATE [OR REPLACE]
FUNCTION?  If so, should there be a way to switch it off?  If so,
would this be implemented globally, or per-function?  Would it be a
postgres run-time setting, or an extension to CREATE FUNCTION syntax,
or something within the PL/pgSQL code (like Perl's 'use strict')?

Cheers,
BJ