Cubicle 1.1.2 documentation and source : Ty.hash

let hash t =
  match t with
    | Tabstract s -> Hstring.hash s
    | Tsum (s, l) -> 
	let h = 
	  List.fold_left 
	    (fun h x -> 13 * h + Hstring.hash x) (Hstring.hash s) l
	in
	abs h
    | _ -> Hashtbl.hash t