From e51a16c072144e4cabc8fc70841aa4e94a9325b6 Mon Sep 17 00:00:00 2001
From: Andrea Asperti <andrea.asperti@unibo.it>
Date: Fri, 22 Oct 2004 11:55:41 +0000
Subject: [PATCH] - reimplemented meta_closed in non CPS way (faster!) - ported
 to typed explicit substitutions

---
 helm/ocaml/cic/cicUtil.ml  | 70 +++++++++++++++++---------------------
 helm/ocaml/cic/cicUtil.mli |  5 ++-
 2 files changed, 33 insertions(+), 42 deletions(-)

diff --git a/helm/ocaml/cic/cicUtil.ml b/helm/ocaml/cic/cicUtil.ml
index 3f6156540..1c5d603ca 100644
--- a/helm/ocaml/cic/cicUtil.ml
+++ b/helm/ocaml/cic/cicUtil.ml
@@ -46,7 +46,7 @@ canonical context *)
 let clean_up_local_context subst metasenv n l =
   let cc =
     (try
-       let (cc,_) = lookup_subst n subst in cc
+       let (cc,_,_) = lookup_subst n subst in cc
      with Subst_not_found _ ->
        try
 	 let (_,cc,_) = lookup_meta n metasenv in cc
@@ -103,44 +103,36 @@ in
  is_closed 0
 ;;
 
-(* CPS iterators on Cic.term ************************************************)
-
-let rec visit_l visit_t map f r = function
-   | []        -> f r
-   | h :: tail -> 
-      let f r = visit_l visit_t map f r tail in 
-      visit_t f r (map h) 
-
-let meta_closed t =
-   let rec visit_t f r = function
-      | Cic.Meta _                     -> raise Exit
-      | Cic.Implicit _
-      | Cic.Sort _      
-      | Cic.Rel _                      -> f r 
-      | Cic.Cast (t, u) 
-      | Cic.Prod (_, t, u) 
-      | Cic.Lambda (_, t, u) 
-      | Cic.LetIn (_, t, u)            -> 
-         let f r = visit_t f r u in visit_t f r t 
-      | Cic.Appl tl                    -> 
-         visit_l visit_t (fun x -> x) f r tl 
-      | Cic.Fix (_, tl)                ->  
-         let f r = visit_l visit_t (fun (_, _, _, u) -> u) f r tl in
-         visit_l visit_t (fun (_, _, t, _) -> t) f r tl
-      | Cic.CoFix (_, tl)              -> 
-         let f r = visit_l visit_t (fun (_, _, u) -> u) f r tl in
-         visit_l visit_t (fun (_, t, _) -> t) f r tl
-      | Cic.Var (k, tl)
-      | Cic.Const (k, tl)             
-      | Cic.MutInd (k, _, tl) 
-      | Cic.MutConstruct (k, _, _, tl) -> 
-         visit_l visit_t (fun (_, u) -> u) f r tl
-      | Cic.MutCase (_, _, t, u, tl)   -> 
-         let f r = visit_l visit_t (fun u -> u) f r tl in
-         let f r = visit_t f r u in
-         visit_t f r t
-   in	  
-   try visit_t (fun x -> x) () t; false with Exit -> true
+let rec is_meta_closed =
+  function
+      Cic.Rel _ -> true
+    | Cic.Meta _ -> false
+    | Cic.Sort _ -> true
+    | Cic.Implicit _ -> assert false
+    | Cic.Cast (te,ty) -> is_meta_closed te && is_meta_closed ty
+    | Cic.Prod (name,so,dest) -> is_meta_closed so && is_meta_closed dest
+    | Cic.Lambda (_,so,dest) -> is_meta_closed so && is_meta_closed dest
+    | Cic.LetIn (_,so,dest) -> is_meta_closed so && is_meta_closed dest
+    | Cic.Appl l ->
+       List.fold_right (fun x i -> i && is_meta_closed x) l true
+    | Cic.Var (_,exp_named_subst)
+    | Cic.Const (_,exp_named_subst)
+    | Cic.MutInd (_,_,exp_named_subst)
+    | Cic.MutConstruct (_,_,_,exp_named_subst) ->
+       List.fold_right (fun (_,x) i -> i && is_meta_closed x)
+        exp_named_subst true
+    | Cic.MutCase (_,_,out,te,pl) ->
+       is_meta_closed out && is_meta_closed te &&
+        List.fold_right (fun x i -> i && is_meta_closed x) pl true
+    | Cic.Fix (_,fl) ->
+        List.fold_right
+          (fun (_,_,ty,bo) i -> i && is_meta_closed ty && is_meta_closed bo
+          ) fl true
+    | Cic.CoFix (_,fl) ->
+         List.fold_right
+          (fun (_,ty,bo) i -> i && is_meta_closed ty && is_meta_closed bo
+          ) fl true
+;;
 
 let xpointer_RE = Str.regexp "\\([^#]+\\)#xpointer(\\(.*\\))"
 let slash_RE = Str.regexp "/"
diff --git a/helm/ocaml/cic/cicUtil.mli b/helm/ocaml/cic/cicUtil.mli
index 0b98e51fa..29657f401 100644
--- a/helm/ocaml/cic/cicUtil.mli
+++ b/helm/ocaml/cic/cicUtil.mli
@@ -27,15 +27,14 @@ exception Meta_not_found of int
 exception Subst_not_found of int
 
 val lookup_meta: int -> Cic.metasenv -> Cic.conjecture
-val lookup_subst: int -> Cic.substitution -> Cic.context * Cic.term
+val lookup_subst: int -> Cic.substitution -> Cic.context * Cic.term * Cic.term
 val exists_meta: int -> Cic.metasenv -> bool
 val clean_up_local_context :
   Cic.substitution -> Cic.metasenv -> int -> (Cic.term option) list 
   -> (Cic.term option) list
 
 val is_closed : Cic.term -> bool
-
-val meta_closed : Cic.term -> bool
+val is_meta_closed : Cic.term -> bool
 
 val term_of_uri: string -> Cic.term
 
-- 
2.39.2