# Convert hash to object with methods
#   o = FreeStruct.new name: 'a'
#   o.name   -> 'a'
#   o[:name] -> 'a'
#   o.name = 'b'
#   o.name 'b'
#   o.name -> 'b'
#   o.name = nil
#   o.name -> nil
#   o.title -> raises error

class FreeStruct
  def initialize hash
    @keys = hash.keys

    hash.each do |key, value|
      ivar = "@#{key}"

      instance_variable_set ivar, value

      define_singleton_method(key) do
        instance_variable_get ivar
      end

      define_singleton_method "#{key}=" do |val|
        instance_variable_set ivar, val
      end
    end
  end

  def [] key
    send key
  end

  def to_h
    @keys.inject({}) do |out, key|
      out[key] = send(key)
      out
    end
  end
end