attr_accessory_ruby.rb

class Object
  def self.my_accessor(*accessor_names)
    accessor_names.each do |name|
      define_method name do
        instance_var_name = "@#{name.to_s}".to_sym
        self.instance_variable_get(instance_var_name)
      end
      writer_name = "#{name.to_s}=".to_sym
      define_method writer_name do |value|
        instance_var_name = "@#{name.to_s}".to_sym
        self.instance_variable_set(instance_var_name, value)
      end
    end
  end
end

class Person
  my_accessor :moof
  def initialize
    @moof = 'foof'
  end
end

me = Person.new

puts me
puts me.moof
me.moof = "woof"
puts me.moof

set_and_get_thing.rb

class Person
  attr_accessor :attrs

  def initialize
    @attrs = {
      :a => 1,
      :b => 1
    }
  end
  
  def get_thing key
    @attrs[key]
  end
  
  def set_thing key, val
    @attrs[key] = val
  end
  
  def method_missing(method_name, *values)
    if method_name.to_s.match /^get_/
      name = method_name.to_s.sub(/^get_/, '')
      return get_thing(name.to_sym)
    end
    if method_name.to_s.match /^set_/
      value = values[0]
      name = method_name.to_s.sub(/^set_/, '').chop
      return set_thing(name.to_sym, value)
    end
  end
end

m1 = Person.new
p m1.attrs

m1.set_c = 2
p m1.attrs

p m1.get_c
p m1.get_d