require 'method_parser'

mp = MethodParser.new File.read('simple_number.rb')
mp.to_a

output:

[
  [:class, :SimpleNumber, 
    [
      [:def, :initialize, :private], 
      [:def, :add, :public], 
      [:def, :multiply, :public], 
      [:def, :divide, :private], 
      [:def, :square, :protected]
    ]
  ]
] 

• update: 9:35pm 15th Sep 2014 *

Implemented to_xml

require 'method_parser'

mp = MethodParser.new File.read('simple_number.rb')
mp.to_xml

output:

<?xml version='1.0' encoding='UTF-8'?>
<doc>
  <klass name='SimpleNumber'>
    <def name='initialize' scope='private'></def>
    <def name='add' scope='public'></def>
    <def name='multiply' scope='public'></def>
    <def name='divide' scope='private'></def>
    <def name='square' scope='protected'></def>
  </klass>
</doc>

• Returning just the Class name and methods
• method_parser

parser gem method_parser