Re: a few small bugs in plpgsql

Hello

2010/10/8 Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>:
> Pavel Stehule <pavel(dot)stehule(at)gmail(dot)com> writes:
>> a) parser allow a labels on invalid positions with strange runtime bug:
>
>> postgres=# CREATE OR REPLACE FUNCTION foo()
>> RETURNS void AS $$
>> BEGIN
>>   FOR i IN 1..2
>>   <<<invalidLabel>>
>>   LOOP
>>     RAISE NOTICE '%',i;
>>   END LOOP;
>> END;
>> $$ LANGUAGE plpgsql;
>> CREATE FUNCTION
>
>> ERROR:  column "invalidlabel" does not exist
>> LINE 2:   <<<invalidLabel>>
>>              ^
>> QUERY:  SELECT 2
>>   <<<invalidLabel>>
>> CONTEXT:  PL/pgSQL function "foo" line 3 at FOR with integer loop variable
>
> That isn't a bug, because the construct isn't a label, and wouldn't be
> even if you'd gotten the number of <'s right ;-).  What you have is an
> expression "2 <<< invalidLabel >>", which given the right operator
> definitions could be perfectly valid.  plpgsql labels can't appear in
> the middle of an SQL expression.
>

I see it now - I did a bug <<<some>>, but with correct text there is same behave

CREATE OR REPLACE FUNCTION foo()
RETURNS void AS $$
BEGIN
FOR i IN 1..10
<<label>>
LOOP
RAISE NOTICE '%', i;
END LOOP;
END;
$$ LANGUAGE plpgsql;
CREATE FUNCTION

Now I understand to interpretation. But there is little bit difficult
to understand to error message. Can be message enhanced to show a
complete expression? Some like

postgres=# select foo();
ERROR: column "label" does not exist
Detail: Expr 10 <<label>>
LINE 2: <<label>>

Regards

Pavel

>                        regards, tom lane
>