structures.scala

  def list: Parser[BList] = {
    delimitedBy(LIST_BEGIN, LIST_END) {
      rep(string | int | list | dict)
    } ^^ (BList(_)) named ("list")
  }

  def dict: Parser[BDict] = {
    delimitedBy(DICT_BEGIN, DICT_END) {
      rep(string ~ (string | int | list | dict))
    } ^^ (_.map { case key ~ value => key -> value }) ^^ (l => BDict(l.toMap)) named ("dict")
  }

  def root = string | int | list | dict