class TomlRB::Table

def accept_visitor(parser)
  parser.visit_table self
end

def ensure_key_not_defined(visited_keys)
  fail ValueOverwriteError.new(full_key) if visited_keys.include?(full_key)
  visited_keys << full_key
end

def full_key
  @dotted_keys.join('.')
end

def initialize(dotted_keys)
  @dotted_keys = dotted_keys
end

def navigate_keys(hash, visited_keys, symbolize_keys = false)
  ensure_key_not_defined(visited_keys)
  current = hash
  keys = symbolize_keys ? @dotted_keys.map(&:to_sym) : @dotted_keys
  keys.each do |key|
    current[key] = {} unless current.key?(key)
    element = current[key]
    current = element.is_a?(Array) ? element.last : element
    # check that key has not been defined before as a scalar value
    fail ValueOverwriteError.new(key) unless current.is_a?(Hash)
  end
  current
end