Revise API for global universes.

Rename Univ.Level.{Qualid -> UGlobal}, remove Univ.Level.Id.

Remove the ability to split the argument of `Univ.Level.Level` into a
dirpath*int pair (except by going through string hacks like
detyping/pretyping(/funind) does).

Id.of_string_soft to turn unnamed universes into qualid is pushed up
to detyping. (TODO some followup PR clean up more)

This makes it pointless to have an opaque type for ints in
Univ.Level: it would only be used as argument to
Univ.Level.UGlobal.make, ie
~~~
open Univ.Level
let x = UGlobal.make dp (Id.make n)
(* vs *)
let x = UGlobal.make dp n
~~~

Remaining places which create levels from ints are various hacks (eg
the dummy in inductive.ml, the Type.n universes in ugraph
sort_universes) and univgen.

UnivGen does have an opaque type for ints used as univ ids since they
get manipulated by the stm.

NB: build breaks due to ocamldep issue if UGlobal is named Global instead.

1 files changed, 7 insertions, 10 deletions

diff --git a/engine/univNames.ml b/engine/univNames.ml
index 6bf1187b65..19705f9d36 100644
--- a/engine/univNames.ml
+++ b/engine/univNames.ml
@@ -16,17 +16,14 @@ open Univ
 let qualid_of_level l =
   match Level.name l with
   | Some qid  ->
-    begin
-    try Nametab.shortest_qualid_of_universe qid
-    with Not_found ->
-      let (dp,n) = Level.Qualid.repr qid in
-      let name = Id.of_string_soft (Level.Id.to_string n) in
-      Libnames.make_qualid dp name
-    end
-  | None ->
-    Libnames.qualid_of_ident @@ Id.of_string_soft (Level.to_string l)
+    (try Some (Nametab.shortest_qualid_of_universe qid)
+     with Not_found -> None)
+  | None -> None
 
-let pr_with_global_universes l = Libnames.pr_qualid (qualid_of_level l)
+let pr_with_global_universes l =
+  match qualid_of_level l with
+  | Some qid  -> Libnames.pr_qualid qid
+  | None -> Level.pr l
 
 (** Global universe information outside the kernel, to handle
     polymorphic universe names in sections that have to be discharged. *)