Re: [HACKERS] merging some features from plpgsql2 project

On 1/8/17 12:03 AM, Pavel Stehule wrote:
>         BTW, I do wish you could change the label of the scope that
>         arguments went into, so that you could use that label to refer
>         to function parameters. If we allowed that it'd perhaps be the
>         best of both worlds: you'd be guaranteed access to all auto
>         variables and parameters, and that access wouldn't need to be
>         tied to the function name (which can be both painful and error
>         prone).
>
>
>     We can talk about compiler directive.
>
>     PRAGMA auto_variables_label(xxxx) -- require function scope only
>
>
> If we know a list of all auto variables, then it can be on function or
> block level - it can create aliases.

Oh, the problem is that if you have an argument with the same name as an 
auto variable you're in trouble.

Probably the easiest thing is to have a scope that sits above the scope 
containing the arguments, and then allow the user to rename both scopes 
if so desired. So in effect you'd end up with

<<plpgsql>> -- new scope
DECLARE
FOUND;
etc
BEGIN  <<function_name>>  DECLARE  argument_1;  argument_2;  BEGIN    -- User supplied block goes here, with optional
label END;
 
END;

Alternatively, we could do...

<<function_name>>
DECLARE
FOUND;
etc
BEGIN  DECLARE-- User's DECLARE  argument_1;  argomuent_2;  -- User supplied declare code  BEGIN -- User's BEGIN  ....
END

That removes one level of nesting. It's probably better to go with the 
first option though, since it's simpler.

In both cases, I'd really like the ability to rename those blocks. 
#pragma would be fine for that.
-- 
Jim Nasby, Data Architect, Blue Treble Consulting, Austin TX
Experts in Analytics, Data Architecture and PostgreSQL
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