Re: setting the _ENV for require

[Sean Conner <sean@...>]

It was thus said that the Great Matthias Kluwe once stated:
> Hi!
> 
> It's easy to "sandbox" a chunk with an environment. Let's say I have a
> file
> 
>     -- mod.lua -----------
>     return function()
>         return a
>     end
>     ----------------------
> 
> Then loading it with a given environment makes it independent of
> `_ENV`:
> 
>     local g = loadfile( 'mod.lua', 't', {
>         a = 42
>     } )()
>     print( g() ) --> prints 42
>     _ENV.a = 23
>     print( g() ) --> prints 42
> 
> That's not the case when using `require`:
> 
>     local f = require 'mod'
>     print( f() ) --> prints 23
>     _ENV.a = 42
>     print( f() ) --> prints 42
> 
> Is there some clever trick to achieve the same effect (meaning to make
> the required module independent of `_ENV')?

  What I do for my modules is:

	if _VERSION == "Lua 5.1" then
	  module("org.conman.date")
	else
	  _ENV = {} -- luacheck: ignore
	end
	
	-- body of module
	
	if _VERSION >= "Lua 5.2" then
	  return _ENV -- luacheck: ignore
	end

  I did it this way to avoid having to rewrite a lot of modules.

  -spc