[api] Miscellaneous consolidation + moves to engine.

We deprecate a few functions that were deprecated in the comments plus
we place `Nameops` and `Univops` in engine where they do seem to
belong in the large picture of code organization.

1 files changed, 40 insertions, 0 deletions

diff --git a/engine/univops.ml b/engine/univops.ml
new file mode 100644
index 000000000..9dc138eb8
--- /dev/null
+++ b/engine/univops.ml
@@ -0,0 +1,40 @@
+(************************************************************************)
+(*  v      *   The Coq Proof Assistant  /  The Coq Development Team     *)
+(* <O___,, *   INRIA - CNRS - LIX - LRI - PPS - Copyright 1999-2017     *)
+(*   \VV/  **************************************************************)
+(*    //   *      This file is distributed under the terms of the       *)
+(*         *       GNU Lesser General Public License Version 2.1        *)
+(************************************************************************)
+
+open Constr
+open Univ
+
+let universes_of_constr c =
+  let rec aux s c = 
+    match kind c with
+    | Const (_, u) | Ind (_, u) | Construct (_, u) ->
+      LSet.fold LSet.add (Instance.levels u) s
+    | Sort u when not (Sorts.is_small u) -> 
+      let u = Term.univ_of_sort u in
+      LSet.fold LSet.add (Universe.levels u) s
+    | _ -> Constr.fold aux s c
+  in aux LSet.empty c
+
+let restrict_universe_context (univs,csts) s =
+  (* Universes that are not necessary to typecheck the term.
+     E.g. univs introduced by tactics and not used in the proof term. *)
+  let diff = LSet.diff univs s in
+  let rec aux diff candid univs ness = 
+    let (diff', candid', univs', ness') = 
+      Constraint.fold
+	(fun (l, d, r as c) (diff, candid, univs, csts) ->
+	  if not (LSet.mem l diff) then
+	    (LSet.remove r diff, candid, univs, Constraint.add c csts)
+	  else if not (LSet.mem r diff) then
+	    (LSet.remove l diff, candid, univs, Constraint.add c csts)
+	  else (diff, Constraint.add c candid, univs, csts))
+	candid (diff, Constraint.empty, univs, ness)
+    in
+      if ness' == ness then (LSet.diff univs diff', ness)
+      else aux diff' candid' univs' ness'
+  in aux diff csts univs Constraint.empty