From: Nicholas Seckar <nseckar@...>
Date: 2005-06-06T02:34:52+09:00
Subject: Re: Creating objects from strings.

Bill wrote:

>
>  def load (filename, classname)
>
>    require filename
>
>    # taken from 
> http://www.ruby-talk.org/cgi-bin/scat.rb/ruby/ruby-talk/9295
>    names = classname.split /::/
>    names.reverse!
>    unf = Object
>    unf = unf.const_get(names.pop) while names.length > 0
>    unf.new
>  end
>
> load ("myfile.rb", "myModule::myClass")
>

This is an excellent place to use inject:

def load(filename, classname)
  require filename
  classname.split('::').inject(Object) {|module, name| module.const_get 
name}.new
end

You might also like to know that const_get will look in the parent 
modules as well. For example,

module A
  module B
  end
end

A.constants #=> ['B']
A.const_get :Object #=> Object
A::Object #=> Unitialized constant A::Object

Because of this I've resorted to using eval "#{module}::#{name}" -- Does 
anyone know of a non-eval way of doing this?

And, as you may or may not know, Ruby comes with a load method, so you 
might want to change your method name to load_instance or something.