eval.rb

def eval_string(klass, attrib)
  s = <<EOS
  class #{klass}
    def #{attrib}
      @#{attrib}
    end
    def #{attrib}=(value)
      @#{attrib} = value
    end
  end
EOS
  return s
end

eval(eval_string(String, "ahmet"))
x = String.new
x.ahmet = "abdi"
puts x.ahmet