Horton

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

Fabien COELHO <coelho@cri.ensmp.fr>

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From: Fabien COELHO <coelho@cri.ensmp.fr>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Alvaro Herrera <alvherre@2ndquadrant.com>, 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: 2017-03-19T20:23:09Z
Lists: pgsql-hackers 
Hello Tom,

> I'm not entirely convinced that function-per-command is an improvement
> though. [...]

> I don't have a definite opinion on that core question yet, since I've not
> read this version of the patch.  Anybody else want to give an opinion?

My 0.02€:

I've already provided my view...

Personnally I like good functions. Maybe a per-command-family set of 
functions could improve the code readability, but (1) I'm not sure this is 
achieved by this patch (eg the if-related state management is now 
dispatched in 4 functions) and (2) I'm not sure that this approach helps 
much with respect to trying to factor out backslash-command-related 
active-or-not argument management.

However I have not looked at the patch in detail. I'm planing to do so 
later this week.

-- 
Fabien.

Commits

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

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