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

Tom Lane wrote:

> I'm not entirely convinced that function-per-command is an improvement
> though. Seems like it would only help to the extent that you could do a
> simple "return" to implement early exit, and it looks to me like that
> doesn't work in a lot of places because you still have to clean up things
> like malloc'd argument strings before you can return. So the question
> we have to answer is whether this way looks cleaner than what we'd get if
> we just changed the logic in-place. For the purpose of answering that
> question, looking at the final state is the right thing to do.
>
> 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?

Currently, exec_command is a 1500-line function. If I had to see how a
single \-command worked, I would have to fold everything but the command
I'm interested in, in case there's something nontrivial at function
start or end (or even in between -- I would have to start by figuring
out whether there's anything other than "else if" somewhere in those
1500 lines). I think splitting into command-specific functions makes
this much easier to follow, particularly if we want to add extra tricks
such as returning early etc.

--
Álvaro Herrera https://www.2ndQuadrant.com/
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