I wrote:
> Given the infrequency of use of postfix operators compared to prefix,
> I am inclined to think that we should change the grammar to make the
> latter easier to use at the expense of the former. On the other hand,
> it seems there's a pretty large risk of backwards-incompatibility here.
> Comments?
I backed away from part of the proposed patch --- changing the
precedence of all the prefix-operator productions to UMINUS would
probably break people's queries. But I've applied the part that
changes the behavior of a_expr Op Op a_expr. This will now be
parsed as an infix operator followed by a prefix operator.
regards, tom lane