On 22 June 2010 18:49, Tom Lane <tgl@sss.pgh.pa.us> wrote:
> Thom Brown <thombrown@gmail.com> writes:
>> Is that the right behaviour though? Shouldn't the signed value reach
>> the cast step rather than the absolute value? Or maybe Postgres could
>> implicitly accept -12345::integer to be (-12345)::integer. Is there a
>> blocking reason as to why it must work this way?
>
> Yes. There is no reason to assume that - means the same thing for every
> datatype. In general, :: should (and does) bind tighter than *every*
> operator, to ensure that the appropriately typed operator is applied.
>
Sorry for adding to the non-DOC drift, but why is - assumed to be a
unary operator on an unsigned integer, rather than parsed as part of
an integer? Integers have digits with an optional - or + prefix (not
unary operators). E.g., ([+\-]?[0-9]+)
-Mike