initial implementation of `ncoercion name : type := body on name : pat to pat`

[helm.git] / helm / software / components / ng_refiner / nCicCoercion.ml

diff --git a/helm/software/components/ng_refiner/nCicCoercion.ml b/helm/software/components/ng_refiner/nCicCoercion.ml
index f2467605f085731d456816feb325ca2e30e4b56a..31768a62dd6ac11e474dca0c2ce997c24c422181 100644 (file)
--- a/helm/software/components/ng_refiner/nCicCoercion.ml
+++ b/helm/software/components/ng_refiner/nCicCoercion.ml
@@ -11,6 +11,9 @@
 
 (* $Id: nCicRefiner.mli 9227 2008-11-21 16:00:06Z tassi $ *)
 
+let debug s = prerr_endline (Lazy.force s);;
+let debug _ = ();;
+
 module COT : Set.OrderedType with type t = NCic.term * int * int = 
   struct
         type t = NCic.term * int * int
@@ -24,24 +27,39 @@ module DB =
 
 type db = DB.t * DB.t
 
-let index_coercion (db_src,db_tgt) c src tgt arity arg =
+let empty_db = DB.empty,DB.empty
+
+class status =
+ object
+  val db = empty_db
+  method coerc_db = db
+  method set_coerc_db v = {< db = v >}
+  method set_coercion_status
+   : 'status. < coerc_db : db; .. > as 'status -> 'self
+   = fun o -> {< db = o#coerc_db >}
+ end
+
+let index_coercion status c src tgt arity arg =
+  let db_src,db_tgt = status#coerc_db in
   let data = (c,arity,arg) in
-(*
-  prerr_endline ("INDEX:" ^ 
+
+  debug (lazy ("INDEX:" ^ 
     NCicPp.ppterm ~metasenv:[] ~subst:[] ~context:[] src ^ " ===> " ^
     NCicPp.ppterm ~metasenv:[] ~subst:[] ~context:[] tgt ^ "  :=  " ^
-    NCicPp.ppterm ~metasenv:[] ~subst:[] ~context:[] c);
-*)
+    NCicPp.ppterm ~metasenv:[] ~subst:[] ~context:[] c ^ " " ^ 
+    string_of_int arg ^ " " ^ string_of_int arity));
+
   let db_src = DB.index db_src src data in
   let db_tgt = DB.index db_tgt tgt data in
-  db_src, db_tgt
+  status#set_coerc_db (db_src, db_tgt)
 ;;
 
-let db () =
+let index_old_db odb (status : #status) =
   List.fold_left 
-    (fun db (_,tgt,clist) -> 
+    (fun status (_,tgt,clist) -> 
        List.fold_left 
-         (fun db (uri,_,arg) ->
+         (fun status (uri,_,arg) ->
+           try
             let c=fst (OCic2NCic.convert_term uri (CicUtil.term_of_uri uri)) in
             let arity = match tgt with | CoercDb.Fun i -> i | _ -> 0 in
             let src, tgt = 
@@ -55,52 +73,58 @@ let db () =
                    NCicSubstitution.subst (NCic.Meta (-1,(0,NCic.Irl 0))) tgt
                  in
 (*
-            prerr_endline (Printf.sprintf "indicizzo %s (%d) : %s ===> %s" 
+            debug (lazy (Printf.sprintf "indicizzo %s (%d)) : %s ===> %s" 
               (NCicPp.ppterm ~metasenv ~subst:[] ~context:[] scty) (arity+1)
               (NCicPp.ppterm ~metasenv ~subst:[] ~context:[] src)
               (NCicPp.ppterm ~metasenv ~subst:[] ~context:[] tgt));
 *)
                 src, tgt
               | t -> 
-                  prerr_endline (
-                    NCicPp.ppterm ~metasenv ~subst:[] ~context:[] t);
+                  debug (lazy (
+                    NCicPp.ppterm ~metasenv ~subst:[] ~context:[] t));
                   assert false
             in
-            index_coercion db c src tgt arity arg)
-         db clist)
-    (DB.empty,DB.empty) (CoercDb.to_list ())
+            index_coercion status c src tgt arity arg
+           with 
+           | NCicEnvironment.BadDependency _ 
+           | NCicTypeChecker.TypeCheckerFailure _ -> status)
+         status clist)
+    status (CoercDb.to_list odb)
 ;;
 
-let look_for_coercion (db_src,db_tgt) metasenv subst context infty expty =
+let look_for_coercion status metasenv subst context infty expty =
+ let db_src,db_tgt = status#coerc_db in
   match infty, expty with
   | (NCic.Meta _ | NCic.Appl (NCic.Meta _::_)), 
     (NCic.Meta _ | NCic.Appl (NCic.Meta _::_)) -> [] 
   | _ ->
-(*
-    prerr_endline ("LOOK FOR COERCIONS: " ^ 
+
+    debug (lazy ("LOOK FOR COERCIONS: " ^ 
       NCicPp.ppterm ~metasenv ~subst ~context infty ^ "  |===> " ^
-      NCicPp.ppterm ~metasenv ~subst ~context expty);
-*)
+      NCicPp.ppterm ~metasenv ~subst ~context expty));
+
     let set_src = DB.retrieve_unifiables db_src infty in
     let set_tgt = DB.retrieve_unifiables db_tgt expty in
     let candidates = CoercionSet.inter set_src set_tgt in
-(*
-    prerr_endline ("CANDIDATES: " ^ 
+
+    debug (lazy ("CANDIDATES: " ^ 
       String.concat "," (List.map (fun (t,_,_) ->
         NCicPp.ppterm ~metasenv ~subst ~context t) 
-      (CoercionSet.elements candidates)));
-*)
+      (CoercionSet.elements candidates))));
+
     List.map
       (fun (t,arity,arg) ->
           let ty = NCicTypeChecker.typeof ~metasenv:[] ~subst:[] [] t in
           let ty, metasenv, args = 
            NCicMetaSubst.saturate ~delta:max_int metasenv subst context ty arity
           in
-  (*       prerr_endline (
+
+          debug (lazy (
             NCicPp.ppterm ~metasenv ~subst:[] ~context:[] ty ^ " --- " ^ 
             NCicPp.ppterm ~metasenv ~subst ~context
             (NCicUntrusted.mk_appl t args) ^ " --- " ^ 
-              string_of_int (List.length args) ^ " == " ^ string_of_int arg); *)
+              string_of_int (List.length args) ^ " == " ^ string_of_int arg)); 
+             
           metasenv, NCicUntrusted.mk_appl t args, ty, List.nth args arg)
       (CoercionSet.elements candidates)
 ;;