From: Joel VanderWerf <vjoel@...>
Date: 2005-07-03T04:35:38+09:00
Subject: Re: Loading a file without cluttering the global namespace

Benjamin Hepp wrote:
> Hello,
> 
> I'm trying to build a module-mechanism in ruby so that I am able to load a
> ruby-file without cluttering up the global namespace of the program.
> 
> For example I want to be able to load a ruby-file, search for methods in
> it, possibly execute one of them and then "unload" the file. When I call
> Kernel#load with wrap = true, everything of the new file is put into an
> anonymous Module, but every other file loaded in the new file itself is
> put into the global namespace again.
> 
> My questions:
> 
> Is it at all possible to prevent this? If so, how to do it?
> Can I access the anonymous Module in an easy manner?
> How to delete/undefine a class or a method?

A partial answer is the script library:

  http://raa.ruby-lang.org/project/script

It cannot unload a library, and it cannot change what namespace .so
extensions put their definitions in, but:

* It wraps a loaded file (and its "local dependencies") in an instance
of the Script class, which is a subclass of Module.

* You can then assign this Script instance to a local var, constant, or
whatever:

  script = Script.load("my-script.rb")

* Top level method defs and constant defs in the wrapped file(s) can be
accessed as methods or constants of this instance:

  script.foo()
  script::Foo

* The "local dependencies" are defined to be any .rb files that can be
found relative to the dir of the main script. This is handled by
redefining #load and #require in the context of the Script instance. If
the specified path is not found locally (or is a .so), then it falls
back to Kernel#require.

* There's also an autoloading feature.

And there's another library to do this kind of thing:

http://codeforpeople.com/lib/ruby/dynaload/