+let is_declared u =
+ match u with
+ [false,x] -> List.exists (fun y -> NUri.eq x y) !universes
+ | _ -> assert false
+;;
+
+let add_constraint strict a b =
+ match a,b with
+ | [false,a2],[false,b2] ->
+ if not (le_path_uri [] strict a2 b2) then (
+ if le_path_uri [] (not strict) b2 a2 then
+ (raise(BadConstraint(lazy("universe inconsistency adding "^pp_constraint strict a2 b2
+ ^ " to:\n" ^ pp_constraints ()))));
+ universes := a2 :: b2 ::
+ List.filter (fun x -> not (NUri.eq x a2 || NUri.eq x b2)) !universes;
+ le_constraints := (strict,a2,b2) :: !le_constraints);
+ history := (`Constr (strict,a,b))::!history;
+ | _ -> raise (BadConstraint
+ (lazy "trying to add a constraint on an inferred universe"))
+;;
+
+let sup l =
+ match l with
+ | [false,_] -> Some l
+ | l ->
+ let bigger_than acc (s1,n1) = List.filter (le_path_uri [] s1 n1) acc in
+ let solutions = List.fold_left bigger_than !universes l in
+ let rec aux = function
+ | [] -> None
+ | u :: tl ->
+ if List.exists (fun x -> le_path_uri [] true x u) solutions then aux tl
+ else Some [false,u]
+ in
+ aux solutions
+;;
+
+
+
+let typecheck_obj,already_set = ref (fun _ -> assert false), ref false;;
+let set_typecheck_obj f =
+ if !already_set then
+ assert false
+ else
+ begin
+ typecheck_obj := f;
+ already_set := true
+ end
+;;
+
+let invalidate_item item =
+ let item_eq a b =
+ match a, b with
+ | `Obj (u1,_), `Obj (u2,_) -> NUri.eq u1 u2
+ | `Constr _, `Constr _ -> a=b (* MAKE EFFICIENT *)
+ | _ -> false
+ in
+ let rec aux to_be_deleted =
+ function
+ [] -> assert false
+ | item'::tl when item_eq item item' -> item'::to_be_deleted,tl
+ | item'::tl -> aux (item'::to_be_deleted) tl
+ in
+ let to_be_deleted,h = aux [] !history in
+ history := h;
+ List.iter
+ (function
+ | `Obj (uri,_) -> NUri.UriHash.remove cache uri
+ | `Constr (strict,[_,u1],[_,u2]) as c ->
+ let w = strict,u1,u2 in
+ if not(List.mem c !history) then
+ le_constraints := List.filter ((<>) w) !le_constraints;
+ | `Constr _ -> assert false
+ ) to_be_deleted
+;;
+
+exception Propagate of NUri.uri * exn;;