| From: | Corey Huinker <corey(dot)huinker(at)gmail(dot)com> |
|---|---|
| To: | Fabien COELHO <coelho(at)cri(dot)ensmp(dot)fr> |
| Cc: | Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>, Greg Stark <stark(at)mit(dot)edu>, Erik Rijkers <er(at)xs4all(dot)nl>, Robert Haas <robertmhaas(at)gmail(dot)com>, Daniel Verite <daniel(at)manitou-mail(dot)org>, Jim Nasby <Jim(dot)Nasby(at)bluetreble(dot)com>, PostgreSQL <pgsql-hackers(at)postgresql(dot)org>, pgsql-hackers-owner(at)postgresql(dot)org |
| Subject: | Re: \if, \elseif, \else, \endif (was Re: PSQL commands: \quit_if, \quit_unless) |
| Date: | 2017-03-12 17:40:15 |
| Message-ID: | CADkLM=chgrfWE3KtH_4i3QjSzicG0+cp3qDZ7-P4p3EDAuYZ2w@mail.gmail.com |
| Views: | Raw Message | Whole Thread | Download mbox | Resend email |
| Thread: | |
| Lists: | pgsql-hackers |
>
>
> (1) document that \if-related commands MUST be on their own
> line (i.e. like cpp #if directives?).
>
I have no opinion on whether \if-related comments must be on their own
line, though I coded as if that were the case.
I want to point out that the goal down the road is to allow rudimentary
expressions beyond just 'will this string cast to boolean true'.
For example, in the earlier thread "Undefined psql variables", I proposed a
slash command that would test if a named psql var were defined, and if not
then assign it a value.
Tom suggested leveraging if-then infrastructure like this
\if not defined(x)
\set x y
\fi
Which would be great. I ask that whatever we decide in terms of how much
more input we read to digest the expression allow for constructs like the
one above.
| From | Date | Subject | |
|---|---|---|---|
| Next Message | David G. Johnston | 2017-03-12 17:45:37 | Re: \if, \elseif, \else, \endif (was Re: PSQL commands: \quit_if, \quit_unless) |
| Previous Message | Tom Lane | 2017-03-12 17:24:29 | Re: \if, \elseif, \else, \endif (was Re: PSQL commands: \quit_if, \quit_unless) |