Re: Unary Operators

Поиск
Список
Период
Сортировка
Искать
От
Tom Lane
Тема
Re: Unary Operators
Дата
Msg-id
2550.1383961919@sss.pgh.pa.us
Ответ на
Unary Operators (Andreas Ulbrich)
Список
Дерево обсуждения
Unary Operators Andreas Ulbrich <andreas.ulbrich@matheversum.de>
Re: Unary Operators Tom Lane <tgl@sss.pgh.pa.us>
Re: Unary Operators Rowan Collins <rowan.collins@gmail.com>
Re: Unary Operators David Johnston <polobo@yahoo.com>
Re: Unary Operators Andreas Ulbrich <andreas.ulbrich@matheversum.de>
Andreas Ulbrich  writes:
> In the documentation I can't find, that / is not possible as an unary 
> operator.
> Are there any restrictions.

Yeah, if you look in the bison grammar you'll find out that the operators
with special precedence are hard-wired as to which syntaxes are allowed:

+ -  	     		prefix or infix
* / % ^ < > =		infix only

It's possible that if we just added some more productions these could be
used in nonstandard ways.  But I think interest in that is really pretty
low, and it might lead to behavior that would be surprising to people
who aren't interested in using them in weird ways.

			regards, tom lane

В списке pgsql-general по дате отправления
От: Sergey Konoplev
Дата:
Сообщение: Re: database redesign
От: Sandeep Gupta
Дата:
FAQ