Re: I propose killing PL/Tcl's "modules" infrastructure

I wrote:
> Now, we could try to fix this bug, and add the regression test coverage
> that the code clearly lacks, and upgrade the documentation about it from
> its currently very sad state. But I think the right answer is just to
> remove the feature altogether.

BTW, I tried to poke into what it would take to write some regression test
coverage, and immediately hit a show-stopper:

$ pltcl_loadmod --help
can't find package Pgtcl
while executing
"package require Pgtcl"
(file "/home/postgres/testversion/bin/pltcl_loadmod" line 10)

That is, these scripts depend on the old Tcl client library, which
we removed from our core distro in 2004 (cf commit 41fa9e9ba).
So we don't even have a way of creating self-contained tests for them.

At this point I think there's no question that src/pl/tcl/modules/
needs to go away. There might be some argument for retaining the
"autoload the unknown module" startup behavior in pltcl proper, but
I think that Andrew Dunstan's proposal of calling an initialization
function is a far cleaner solution.

regards, tom lane