Re: review: psql: edit function, show function commands patch

On Sun, Aug 1, 2010 at 11:35 AM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
> Robert Haas <robertmhaas@gmail.com> writes:
>> On Sun, Aug 1, 2010 at 10:47 AM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
>>> The need to count lines manually in function definitions is
>>> far less than it was back when that kluge was put in.
>
>> Why?
>
> That hack goes back to plpgsql's prehistory (it's there, though sans
> comment, in plpgsql's scan.l 1.1).  We had none of the current support
> for identifying error locations by cursor position and/or quoting part
> of the source text back at you.  Let me illustrate what happened with
> a simple syntax error in PG 7.0:
>
> play=> create function fool() returns int as '
> play'> begin
> play'>   fool
> play'> end' language 'plpgsql';
> CREATE
> play=> select fool();
> NOTICE:  plpgsql: ERROR during compile of fool near line 2
> ERROR:  missing ; at end of SQL statement
> play=>
>
> So you *had* to count lines, and do it accurately too, to figure out
> even pretty simple syntax errors.
>
> Personally, rather than sweat about what the exact definition of line
> numbers is, I think we should be moving further in the direction of
> being able to regurgitate source text to identify error locations.

I basically agree with that; but on the other hand, in a large
PL/pgsql function, you may have very similar-looking text in multiple
places.  So line numbers are good, too: but then you weren't proposing
to remove those, I assume, just to augment them with additional
information.

--
Robert Haas
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