module type PrintableType = sig
  type t
  val pp : out_channel -> t -> unit
  val pp_list : out_channel -> t list -> unit
end

module Node : sig
  type t = {
    id: int;
  }
  val compare : t -> t -> int
  val create : unit -> t
end

module NodeMap : sig
  include Map.S with type key = Node.t

  val add_to_list_last : key -> 'a -> 'a list t -> 'a list t
end

module NodeSet : Set.S with type elt = Node.t


type 'a cfginternal = {
  empty: bool;
  nodes: NodeSet.t;
  edges: (Node.t * (Node.t option)) NodeMap.t;
  reverse_edges: (Node.t list) NodeMap.t;
  input_val: int option;
  input_output_var: (string * string) option;
  initial: Node.t option;
  terminal: Node.t option;
  content: 'a list NodeMap.t;
}

module type C = sig
  type elt
  type t = elt cfginternal

  val empty : t
  val merge : t -> t -> Node.t -> Node.t -> t
  val concat : t -> t -> t
  val add_to_last_node : elt -> t -> t

  val pp : out_channel -> t -> unit
end

module Make (M: PrintableType) : C with type elt = M.t