X-Git-Url: http://matita.cs.unibo.it/gitweb/?a=blobdiff_plain;f=helm%2Fsoftware%2Fcomponents%2Flibrary%2FcoercDb.ml;h=b7e3902296fc986edbffe93a7f5a161542c33e62;hb=2dd6e8f11fa3ac2995f326ecb742d9b4e8948fce;hp=8b7982ea0576645c531fc82e5c599633ffcf39b2;hpb=9ff32d2a3efcf850ea52fe0223a5152f8777aee5;p=helm.git

diff --git a/helm/software/components/library/coercDb.ml b/helm/software/components/library/coercDb.ml
index 8b7982ea0..b7e390229 100644
--- a/helm/software/components/library/coercDb.ml
+++ b/helm/software/components/library/coercDb.ml
@@ -25,75 +25,151 @@
 
 (* $Id$ *)
 
-type coerc_carr = Uri of UriManager.uri | Sort of Cic.sort | Term of Cic.term
-exception EqCarrNotImplemented of string Lazy.t
-exception EqCarrOnNonMetaClosed
+let debug = false
+let debug_print =
+  if debug then fun x -> prerr_endline (Lazy.force x)
+  else ignore
+;;
+
+type coerc_carr = 
+  | Uri of UriManager.uri 
+  | Sort of Cic.sort 
+  | Fun of int 
+  | Dead
+;;
+
+type saturations = int
+type coerced_pos = int
+type coercion_entry = 
+  coerc_carr * coerc_carr * UriManager.uri * saturations * coerced_pos
+
+type coerc_db = (* coercion_entry grouped by carrier with molteplicity *)
+ (coerc_carr * coerc_carr * 
+   (UriManager.uri * int * saturations * coerced_pos) list) list
 
-let db = ref []
+let db =  ref ([] : coerc_db)
+let dump () = !db 
+let restore coerc_db = db := coerc_db
+let empty_coerc_db = []
 
-let coerc_carr_of_term t =
+let rec coerc_carr_of_term t a =
  try
-  match t with
-     Cic.Sort s -> Sort s
-   | Cic.Appl (t::_)
-   | t -> Uri (CicUtil.uri_of_term t)
- with Invalid_argument _ ->
-  Term t
+  match t, a with
+   | Cic.Sort s, 0 -> Sort s
+   | Cic.Appl (t::_), 0 -> coerc_carr_of_term t a
+   | t, 0 -> Uri (CicUtil.uri_of_term t)
+   | _, n -> Fun n
+ with Invalid_argument _ -> Dead
 ;;
 
-let rec name_of_carr = function
+let string_of_carr = function
   | Uri u -> UriManager.name_of_uri u
   | Sort s -> CicPp.ppsort s
-  | Term (Cic.Appl ((Cic.Const (uri, _))::_)) 
-  | Term (Cic.Appl ((Cic.MutInd (uri, _, _))::_)) 
-  | Term (Cic.Appl ((Cic.MutConstruct (uri, _, _, _))::_)) -> 
-        UriManager.name_of_uri uri
-  | Term (Cic.Prod (_,_,t)) -> name_of_carr (Term t)
-  | Term t -> 
-      prerr_endline ("CoercDb.name_of_carr:" ^ CicPp.ppterm t); 
-      "FixTheNameMangler"
+  | Fun i -> "FunClass_" ^ string_of_int i   
+  | Dead -> "UnsupportedCarrier"
+;;
 
-let eq_carr src tgt =
+let eq_carr ?(exact=false) src tgt =
   match src, tgt with
-  | Uri src, Uri tgt -> UriManager.eq src tgt
-  | Sort (Cic.Type _), Sort (Cic.Type _) -> true
-  | Sort src, Sort tgt when src = tgt -> true
-  | Term t1, Term t2 ->
-      if t1 = t2 then true
-      else
-        if CicUtil.is_meta_closed t1 && CicUtil.is_meta_closed t2 then
-          raise 
-          (EqCarrNotImplemented 
-          (lazy ("Unsupported carr for coercions: " ^ 
-          CicPp.ppterm t1 ^ " or " ^ CicPp.ppterm t2)))
-      else raise EqCarrOnNonMetaClosed
+  | Uri src, Uri tgt -> 
+      let coarse_eq = UriManager.eq src tgt in
+      let t = CicUtil.term_of_uri src in
+      let ty,_ = CicTypeChecker.type_of_aux' [] [] t CicUniv.oblivion_ugraph in
+      (match ty, exact with
+      | Cic.Prod _, true -> false
+      | Cic.Prod _, false -> coarse_eq
+      | _ -> coarse_eq) 
+  | Sort _, Sort _ -> true
+  | Fun _,Fun _ when not exact -> true (* only one Funclass *)
+  | Fun i,Fun j when i = j -> true (* only one Funclass *)
   | _, _ -> false
+;;
 
-let to_list () =
-  !db
-
-let add_coercion c =
-  db := c :: !db
+let to_list db =
+  List.map (fun (s,t,l) -> s,t,List.map (fun a,_,b,c -> a,b,c) l) db
+;;
 
-let remove_coercion p = 
-  db := List.filter (fun u -> not(p u)) !db
+let rec myfilter p = function
+  | [] -> []
+  | (s,t,l)::tl ->
+      let l = 
+        HExtlib.filter_map 
+          (fun (u,n,saturations,cpos) as e -> 
+            if p (s,t,u,saturations,cpos) then
+              if n = 1 then None
+              else Some (u,n-1,saturations,cpos)
+            else Some e) 
+          l 
+      in
+      if l = [] then myfilter p tl else (s,t,l)::myfilter p tl
+;;
+  
+let remove_coercion p = db := myfilter p !db;;
 
 let find_coercion f =
-  List.map (fun (_,_,x) -> x) (List.filter (fun (s,t,_) -> f (s,t)) !db)
-
-let is_a_coercion u =
-  List.exists (fun (_,_,x) -> UriManager.eq x u) !db
+  List.map
+   (fun (uri,_,saturations,_) -> uri,saturations)
+   (List.flatten
+    (HExtlib.filter_map (fun (s,t,l) -> if f (s,t) then Some l else None) !db))
+;;
 
-let get_carr uri =
+let is_a_coercion t = 
   try
-    let src, tgt, _ = List.find (fun (_,_,x) -> UriManager.eq x uri) !db in
-    src, tgt
-  with Not_found -> assert false (* uri must be a coercion *)
-
-let term_of_carr = function
-  | Uri u -> CicUtil.term_of_uri u
-  | Sort s -> Cic.Sort s
-  | Term _ -> assert false
-  
+   let uri = CicUtil.uri_of_term t in
+   match 
+     HExtlib.filter_map
+      (fun (src,tgt,xl) -> 
+         let xl = List.filter (fun (x,_,_,_) -> UriManager.eq uri x) xl in
+         if xl = [] then None else Some (src,tgt,xl))
+      !db
+   with
+   | [] -> None
+   | (_,_,[])::_ -> assert false
+   | [src,tgt,[u,_,s,p]] -> Some (src,tgt,u,s,p)
+   | (src,tgt,(u,_,s,p)::_)::_ -> 
+       debug_print 
+         (lazy "coercion has multiple entries, returning the first one");
+       Some (src,tgt,u,s,p)
+  with Invalid_argument _ -> 
+    debug_print (lazy "this term is not a constant");      
+    None
+;;
 
+let add_coercion (src,tgt,u,saturations,cpos) =
+  let f s t = eq_carr s src && eq_carr t tgt in
+  let where = List.filter (fun (s,t,_) -> f s t) !db in
+  let rest = List.filter (fun (s,t,_) -> not (f s t)) !db in
+  match where with
+  | [] -> db := (src,tgt,[u,1,saturations,cpos]) :: !db
+  | (src,tgt,l)::tl ->
+      assert (tl = []); (* not sure, this may be a feature *)
+      if List.exists (fun (x,_,_,_) -> UriManager.eq u x) l then
+        let l = 
+          let l = 
+            (* this code reorders the list so that adding an already declared 
+             * coercion moves it to the begging of the list *)
+            let item = List.find (fun (x,_,_,_) -> UriManager.eq u x) l in
+            let rest=List.filter (fun (x,_,_,_) -> not (UriManager.eq u x)) l in
+            item :: rest
+          in
+          List.map
+          (fun (x,n,x_saturations,x_cpos) as e ->
+            if UriManager.eq u x then
+             (* not sure, this may be a feature *)
+             (assert (x_saturations = saturations && x_cpos = cpos);       
+             (x,n+1,saturations,cpos))
+            else e)
+          l
+        in
+        db := (src,tgt,l)::tl @ rest
+      else
+        db := (src,tgt,(u,1,saturations,cpos)::l)::tl @ rest
+;;
 
+let prefer u = 
+  let prefer (s,t,l) =
+    let lb,la = List.partition (fun (uri,_,_,_) -> UriManager.eq uri u) l in
+    s,t,lb@la
+  in
+  db := List.map prefer !db;
+;;