class Arendelle

# File lib/arendelle.rb, line 4
def initialize(**opts)
  opts.each { |k, v| self[k] = v }
end

# File lib/arendelle.rb, line 8
def []=(key, value)
  ivar = "@_#{key}"
  raise FrozenVariableError if instance_variable_get(ivar)

  instance_variable_set(ivar, value.freeze)

  if key[0] =~ /\d/
    define_singleton_method("_#{key}") do
      instance_variable_get(ivar)
    end
  else
    define_singleton_method(key) do
      instance_variable_get(ivar)
    end
  end
end

# File lib/arendelle.rb, line 25
def to_h
  instance_variables.each_with_object({}) do |ivar, hash|
    key = ivar.to_s[2..-1]
    value = send(key)
    new_value = value.is_a?(Arendelle) ? value.to_h : value
    hash[key.to_sym] = new_value
  end
end