From: nobu.nokada@...
Date: 2002-02-01T14:05:04+09:00
Subject: Re: using extend dynamically

Hi,

At Thu, 31 Jan 2002 19:30:37 -0800,
<ptkwt@aracnet.com> wrote:
> What if I had a string that contained the name of a module that I wanted 
> to extend an object with?
(snip)
> Is there any way of doing this without resorting to eval? (or case)

It doesn't concern #extend at all, however, you can use
Module#const_get to get a constant from its name.

> obj = MyClass.new(moduleToMix) #this won't work

  obj = MyClass.new(Object.const_get(moduleToMix))

For nested class:

  class Module
    def nested_const(n)
      if (n = n.split('::')).first.empty?
        k = ::Object
        n.shift
      else
        k = self
      end
      n.each {|n| k = k.const_get(n)}
      k
    end
  end

  p Object.nested_const("::File::Stat")

-- 
Nobu Nakada