Horton

Re: \if, \elseif, \else, \endif (was Re: PSQL commands: \quit_if, \quit_unless)

Tom Lane <tgl@sss.pgh.pa.us>

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From: Tom Lane <tgl@sss.pgh.pa.us>
To: Fabien COELHO <coelho@cri.ensmp.fr>
Cc: Corey Huinker <corey.huinker@gmail.com>, Daniel Verite <daniel@manitou-mail.org>, "David G. Johnston" <david.g.johnston@gmail.com>, Greg Stark <stark@mit.edu>, Erik Rijkers <er@xs4all.nl>, Robert Haas <robertmhaas@gmail.com>, Jim Nasby <Jim.Nasby@bluetreble.com>, PostgreSQL <pgsql-hackers@postgresql.org>, pgsql-hackers-owner@postgresql.org
Date: 2017-03-30T04:15:59Z
Lists: pgsql-hackers

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Fabien COELHO <coelho@cri.ensmp.fr> writes:
>> New Patch v29: Now with less coverage!

> Patch applies cleanly. Make check ok. Feature still works!

I've been hacking on this for about two full days now, and have gotten
it to a point where I think it's committable.  Aside from cosmetic
changes, I've made it behave reasonably for cases where \if is used
on portions of a query, for instance

SELECT
\if :something
    var1
\else
    var2
\endif
FROM table;

which as I mentioned a long time ago is something that people will
certainly expect to work.  I also cleaned up a lot of corner-case
discrepancies between how much text is consumed in active-branch and
inactive-branch cases (OT_FILEPIPE is a particularly nasty case in that
regard :-()

I plan to read this over again tomorrow and then push it, if there are
not objections/corrections.

			regards, tom lane

Commits

  1. Support \if ... \elif ... \else ... \endif in psql scripting.

  2. Add a "void *" passthrough pointer for psqlscan.l's callback functions.