ruby AOP

aop.rb

class A
  def a
    puts "a"
  end
end

module Logger
  def log(method_name)
    m = self.instance_method(method_name)
    undef_method method_name
    define_method method_name.to_s do
      puts "start"
      m.bind(self).call
      puts "end"
    end
  end
end

A.extend Logger

A.log :a

A.new.a