Re: Integer parsing bug?

On Wed, Mar 03, 2004 at 06:27:07PM -0500, Tom Lane wrote:
> Steve Atkins <steve(at)blighty(dot)com> writes:
> >> test=> select -2147483648::int;
> >> ERROR: integer out of range
>
> There is no bug here. You are mistakenly assuming that the above
> represents
> select (-2147483648)::int;
> But actually the :: operator binds more tightly than unary minus,
> so Postgres reads it as
> select -(2147483648::int);
> and quite rightly fails to convert the int8 literal to int.
>
> If you write it with the correct parenthesization it works:
>
> regression=# select -2147483648::int;
> ERROR: integer out of range
> regression=# select (-2147483648)::int;

OK... That makes sense if the parser has no support for negative
constants, but it doesn't seem like intuitive behaviour.

BTW, the original issue that led to this was:

db=>CREATE function t(integer) RETURNS integer AS '
BEGIN
return 0;
END;
' LANGUAGE 'plpgsql';

db=> select t(-2147483648);
ERROR: function t(bigint) does not exist

Which again makes sense considering the way the parser works, but
still seems to violate the principle of least surprise.

Cheers,
Steve