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

Corey Huinker <corey.huinker@gmail.com> writes:
> After some research, GetVariable is called by psql_get_variable, which is
> one of the callback functions passed to psql_scan_create(). So passing a
> state variable around probably isn't going to work and PsqlFileState now
> looks like the best option.

Ah, I see why *that* wants to know about it ... I think.  I suppose you're
arguing that variable expansion shouldn't be able to insert, say, an \else
in a non-active branch?  Maybe, but if it can insert an \else in an active
branch, then why not non-active too?  Seems a bit inconsistent.

Anyway, what this seems to point up is that maybe we should've allowed
for a passthrough "void *" argument to the psqlscan callback functions.
There wasn't one in the original design but it's a fairly standard part
of our usual approach to callback functions, so it's hard to see an
objection to adding one now.
        regards, tom lane