document.rb

# I wanted to
# define a class which has a foo method
# which can also be called from a block
# so you can spice it and call the super
# class method again
#
# thanks to banisterfiend, xxxxxx and coderr
# for helping me on this one

class Document
  def self.foo(test)
    puts "foo: #{test}"
  end
  
  module TabProxy
    def foo(test)
      puts "block"
      super(test)
    end
  end
  
  def self.tab( name, &block )
    context = eval 'self', block.binding
    dup_context = context.dup
    dup_context.extend TabProxy
    dup_context.instance_eval &block
    dup_context.instance_variables.each do |v|
      context.instance_variable_set(v, dup_context.instance_variable_get(v))
    end
  end
end

dummy.rb

class Dummy < Document
  foo :foo

  tab :general do
    foo :bar
  end
        
  foo :baz
end

# should output
foo: foo
block
foo: bar
foo: baz