Metaprogramming example

gistfile1.rb

class Person
  def initialize(options = {})
    options.each do |key, value|
      self.instance_variable_set(:"@#{key}", value)
      
      self.class.send(:define_method, key) do
        self.instance_variable_get(:"@#{key}")
      end
      
      self.class.send(:define_method, "#{key}=".intern) do |*args|
        self.instance_variable_set(:"@#{key}", args.first)
      end
    end
  end
end

p = Person.new(:first => "alice", :last => "android", :city => "nyc", :state => "state", :lang => "ruby")

puts p.first

p.first = "bob"

puts p.first