Re: How can a module intentionally fail to load?

[Sean Conner <sean@...>]

It was thus said that the Great nobody once stated:
> On 2018-08-07 04:32, Sean Conner wrote:>
> >	-----[ my-tls.lua / loaded as a module ]----
> >
> >	local tls = require "org.conman.tls"
> >
> >	if tls.LIBRESSL_VERSION < 0x2050000f then
> >	  ??? there's no point in continuing with loading
> >	  ??? this module, because libtls will not let us
> >	  ??? control the socket.
> >	end
> >
> >   How to I abort the module?  There's nothing I can find in the
> >documentation to deal with this, unless I'm missing something.
> 
> Does just throwing an error or assert()ing the test work?

  It kind of works.  I get:

> tls = require "org.conman.nfl.tls"
/usr/local/share/lua/5.1/org/conman/nfl/tls.lua:41: too old a version of TLS
stack traceback:
        [C]: in function 'assert'
        /usr/local/share/lua/5.1/org/conman/nfl/tls.lua:41: in main chunk
        [C]: in function 'require'
        stdin:1: in main chunk
        [C]: ?
> 

But ...

> print(package.loaded['org.conman.nfl.tls'])
userdata: 0x8064634
> 

I think the userdata is the .so file (because each userdata in the TLS
module has a __tostring() method assigned to it), which is an unexpected
result.

I suppose it's good enough.

By the way, when it works,

> tls = require "org.conman.nfl.tls"
> print(package.loaded['org.conman.nfl.tls'])
table: 0x843fc18
> 

  -spc