method chain

gistfile1.rb

class A
  def b
    data = [1, 2, 3]
    def data.foo!
      self.sample
    end
    data
  end
end

A.new.b.foo! # => 2

# --------------------------------------------------------
# OR by 'extend'
# --------------------------------------------------------

class A
  def b
    data = [1, 2, 3]
    data.send :extend, InstanceMethods
    data
  end
end

module InstanceMethods
  def foo!
    self.sample
  end
end

A.new.b.foo! # => 1

nice code!