Demonstrating some namespacing layouts in ruby

namespaces.rb

module Sequel
    class Model
    end
end

module Models
    class User < Sequel::Model; end
    class Post < Sequel::Model; end
end

begin
    class Models::User
        $p = Post
    end
rescue NameError
    class Models::User
        $p = self
    end
end

class Models::Post
    if $p == self
        puts "p was assigned to me"
    else
        puts "p was assigned to something else"
    end
end

module Models
    class User
        $p = Post
    end
end

class Models::Post
    if $p == self
        puts "p was assigned to me"
    else
        puts "p was assigned to something else"
    end
end

__END__

OUTPUT:
    p was assigned to something else
    p was assigned to me