From: Robert Klemme <shortcutter@...>
Date: 2006-04-19T19:01:42+09:00
Subject: Re: Nested scopes

2006/4/19, Yoann Guillot <john-rubytalk@ofjj.net>:
> Hi,
>
> I just discovered a behavior of ruby that seems strange to me.
> I have a module containing classes, and i'd like those classes to be
> able to call some method of the module, so i tried different solutions :
>
> module Foo
>   def self.bar
>     puts "bar!"
>   end
>
>   bar # works
>
>   class Baz
>     # bar      # doesn't work
>     # self.bar # doesn't work
>     Foo.bar    # need to know the module name
>   end
> end
>
> I'd like to be able to call the method from Foo::Baz without knowing the
> name of the module, but the only way i found is to call Foo.bar from
> inside Baz.
>
> Now if you replace "module Foo end" by "Module.new.module_eval {}"...
>
> Shouldn't ruby walk the nesting stack when it doesn't find a method name ?
> Is this going to change in 2.0 ?

No. But there's a simple cure (that we might even suggest to go into
the std lib):

class Module
  def outer
    name.split('::')[0..-2].inject(::Object){|cl,n| cl.const_get n}
  end
end

Now you can do

module Foo
  def self.yeah; puts "yeah!" end
  class Bar
    p outer
    outer.yeah
    class Baz
      p outer
    end
  end
end
p outer

and get

Foo
yeah!
Foo::Bar
Object

:-)

Kind regards

robert

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