@type reason() ::
  {:token, token :: String.t()}
  | {:wrong_closing_tag, open_tag :: String.t(), close_tag :: String.t()}
  | {:invalid_pi, pi_name :: String.t()}
  | {:invalid_encoding, encoding :: String.t()}
  | {:bad_return, {event :: atom(), return :: term()}}

@type t() :: %Sassone.ParseError{
  __exception__: true,
  binary: String.t(),
  position: non_neg_integer(),
  reason: reason()
}