X-Git-Url: http://matita.cs.unibo.it/gitweb/?a=blobdiff_plain;f=helm%2Focaml%2Fcic_unification%2FcicMetaSubst.ml;h=718951c68a579756e4c4bd1d0994c835d28e2bac;hb=4167cea65ca58897d1a3dbb81ff95de5074700cc;hp=021e87ea5c6a6c1221566fcf42b3b0dfe6bca738;hpb=17cc9a1c6353a5a57562434e9938fb54ca78b9c6;p=helm.git

diff --git a/helm/ocaml/cic_unification/cicMetaSubst.ml b/helm/ocaml/cic_unification/cicMetaSubst.ml
index 021e87ea5..718951c68 100644
--- a/helm/ocaml/cic_unification/cicMetaSubst.ml
+++ b/helm/ocaml/cic_unification/cicMetaSubst.ml
@@ -47,7 +47,7 @@ let reset_counters () =
  metasenv_length := 0;
  context_length := 0
 let print_counters () =
-  debug_print (Printf.sprintf
+  debug_print (lazy (Printf.sprintf
 "apply_subst: %d
 apply_subst_context: %d
 apply_subst_metasenv: %d
@@ -64,13 +64,13 @@ context length: %d (avg = %.2f)
   ((float !metasenv_length) /. (float !apply_subst_metasenv_counter))
   !context_length
   ((float !context_length) /. (float !apply_subst_context_counter))
-  )*)
+  ))*)
 
 
 
-exception MetaSubstFailure of string
-exception Uncertain of string
-exception AssertFailure of string
+exception MetaSubstFailure of string Lazy.t
+exception Uncertain of string Lazy.t
+exception AssertFailure of string Lazy.t
 exception DeliftingARelWouldCaptureAFreeVariable;;
 
 let debug_print = fun _ -> ()
@@ -191,8 +191,8 @@ let apply_subst_gen ~appl_fun subst term =
             List.map (function None -> None | Some t -> Some (um_aux t)) l
           in
            C.Meta (i,l'))
-    | C.Sort _ as t -> t
-    | C.Implicit _ -> assert false
+    | C.Sort _
+    | C.Implicit _ as t -> t
     | C.Cast (te,ty) -> C.Cast (um_aux te, um_aux ty)
     | C.Prod (n,s,t) -> C.Prod (n, um_aux s, um_aux t)
     | C.Lambda (n,s,t) -> C.Lambda (n, um_aux s, um_aux t)
@@ -232,17 +232,6 @@ let apply_subst_gen ~appl_fun subst term =
 ;;
 
 let apply_subst =
-(* CSC: old code that never performs beta reduction
-  let appl_fun um_aux he tl =
-    let tl' = List.map um_aux tl in
-      begin
-       match um_aux he with
-          Cic.Appl l -> Cic.Appl (l@tl')
-        | he' -> Cic.Appl (he'::tl')
-      end
-  in
-  apply_subst_gen ~appl_fun
-*)
   let appl_fun um_aux he tl =
     let tl' = List.map um_aux tl in
     let t' =
@@ -252,18 +241,7 @@ let apply_subst =
     in
      begin
       match he with
-         Cic.Meta (m,_) ->
-          let rec beta_reduce =
-           function
-              (Cic.Appl (Cic.Lambda (_,_,t)::he'::tl')) ->
-                let he'' = CicSubstitution.subst he' t in
-                 if tl' = [] then
-                  he''
-                 else
-                  beta_reduce (Cic.Appl(he''::tl'))
-            | t -> t
-          in
-           beta_reduce t'
+         Cic.Meta (m,_) -> CicReduction.head_beta_reduce t'
        | _ -> t'
      end
   in
@@ -310,9 +288,15 @@ let apply_subst_metasenv subst metasenv =
 
 let ppterm subst term = CicPp.ppterm (apply_subst subst term)
 
-let ppterm_in_context subst term name_context =
+let ppterm_in_name_context subst term name_context =
  CicPp.pp (apply_subst subst term) name_context
 
+let ppterm_in_context subst term context =
+ let name_context =
+  List.map (function None -> None | Some (n,_) -> Some n) context
+ in
+  ppterm_in_name_context subst term name_context
+
 let ppcontext' ?(sep = "\n") subst context =
  let separate s = if s = "" then "" else s ^ sep in
   List.fold_right 
@@ -320,13 +304,13 @@ let ppcontext' ?(sep = "\n") subst context =
      match context_entry with
         Some (n,Cic.Decl t) ->
          sprintf "%s%s : %s" (separate i) (CicPp.ppname n)
-          (ppterm_in_context subst t name_context), (Some n)::name_context
+          (ppterm_in_name_context subst t name_context), (Some n)::name_context
       | Some (n,Cic.Def (bo,ty)) ->
          sprintf "%s%s : %s := %s" (separate i) (CicPp.ppname n)
           (match ty with
               None -> "_"
-            | Some ty -> ppterm_in_context subst ty name_context)
-          (ppterm_in_context subst bo name_context), (Some n)::name_context
+            | Some ty -> ppterm_in_name_context subst ty name_context)
+          (ppterm_in_name_context subst bo name_context), (Some n)::name_context
        | None ->
           sprintf "%s_ :? _" (separate i), None::name_context
     ) context ("",[])
@@ -337,7 +321,7 @@ let ppsubst_unfolded subst =
       (fun (idx, (c, t,_)) ->
         let context,name_context = ppcontext' ~sep:"; " subst c in
          sprintf "%s |- ?%d:= %s" context idx
-          (ppterm_in_context subst t name_context))
+          (ppterm_in_name_context subst t name_context))
        subst)
 (* 
         Printf.sprintf "?%d := %s" idx (CicPp.ppterm term))
@@ -350,19 +334,19 @@ let ppsubst subst =
       (fun (idx, (c, t, _)) ->
         let context,name_context = ppcontext' ~sep:"; " [] c in
          sprintf "%s |- ?%d:= %s" context idx
-          (ppterm_in_context [] t name_context))
+          (ppterm_in_name_context [] t name_context))
        subst)
 ;;
 
 let ppcontext ?sep subst context = fst (ppcontext' ?sep subst context)
 
-let ppmetasenv ?(sep = "\n") metasenv subst =
+let ppmetasenv ?(sep = "\n") subst metasenv =
   String.concat sep
     (List.map
       (fun (i, c, t) ->
         let context,name_context = ppcontext' ~sep:"; " subst c in
          sprintf "%s |- ?%d: %s" context i
-          (ppterm_in_context subst t name_context))
+          (ppterm_in_name_context subst t name_context))
       (List.filter
         (fun (i, _, _) -> not (List.mem_assoc i subst))
         metasenv))
@@ -558,10 +542,10 @@ let rec restrict subst to_be_restricted metasenv =
           (more @ more_to_be_restricted @ more_to_be_restricted',
           metasenv')
         with Occur ->
-          raise (MetaSubstFailure (sprintf
+          raise (MetaSubstFailure (lazy (sprintf
             "Cannot restrict the context of the metavariable ?%d over the hypotheses %s since metavariable's type depends on at least one of them"
-	    n (names_of_context_indexes context to_be_restricted)))) 
-      metasenv ([], []) 
+	    n (names_of_context_indexes context to_be_restricted)))))
+      metasenv ([], [])
   in
   let (more_to_be_restricted', subst) = (* restrict subst *)
     List.fold_right
@@ -589,16 +573,16 @@ let rec restrict subst to_be_restricted metasenv =
 	    @ more_to_be_restricted'@more_to_be_restricted'' in
           (more, subst')
         with Occur ->
-          let error_msg = sprintf
+          let error_msg = lazy (sprintf
             "Cannot restrict the context of the metavariable ?%d over the hypotheses %s since ?%d is already instantiated with %s and at least one of the hypotheses occurs in the substituted term"
             n (names_of_context_indexes context to_be_restricted) n
-            (ppterm subst term)
+            (ppterm subst term))
 	  in 
           (* DEBUG
-          debug_print error_msg;
-          debug_print ("metasenv = \n" ^ (ppmetasenv metasenv subst));
-          debug_print ("subst = \n" ^ (ppsubst subst)); 
-          debug_print ("context = \n" ^ (ppcontext subst context)); *)
+          debug_print (lazy error_msg);
+          debug_print (lazy ("metasenv = \n" ^ (ppmetasenv metasenv subst)));
+          debug_print (lazy ("subst = \n" ^ (ppsubst subst)));
+          debug_print (lazy ("context = \n" ^ (ppcontext subst context))); *)
           raise (MetaSubstFailure error_msg))) 
       subst ([], []) 
   in
@@ -614,8 +598,8 @@ let delift n subst context metasenv l t =
    otherwise the occur check does not make sense *)
 
 (*
- debug_print ("sto deliftando il termine " ^ (CicPp.ppterm t) ^ " rispetto
- al contesto locale " ^ (CicPp.ppterm (Cic.Meta(0,l)))); 
+ debug_print (lazy ("sto deliftando il termine " ^ (CicPp.ppterm t) ^ " rispetto
+ al contesto locale " ^ (CicPp.ppterm (Cic.Meta(0,l)))));
 *)
 
  let module S = CicSubstitution in
@@ -645,10 +629,10 @@ let delift n subst context metasenv l t =
                 deliftaux k (S.lift m t)
              | Some (_,C.Decl t) ->
                 C.Rel ((position (m-k) l) + k)
-             | None -> raise (MetaSubstFailure "RelToHiddenHypothesis")
+             | None -> raise (MetaSubstFailure (lazy "RelToHiddenHypothesis"))
            with
             Failure _ ->
-             raise (MetaSubstFailure "Unbound variable found in deliftaux")
+             raise (MetaSubstFailure (lazy "Unbound variable found in deliftaux"))
           )
      | C.Var (uri,exp_named_subst) ->
         let exp_named_subst' =
@@ -662,9 +646,9 @@ let delift n subst context metasenv l t =
          with CicUtil.Subst_not_found _ ->
            (* see the top level invariant *)
            if (i = n) then 
-            raise (MetaSubstFailure (sprintf
+            raise (MetaSubstFailure (lazy (sprintf
               "Cannot unify the metavariable ?%d with a term that has as subterm %s in which the same metavariable occurs (occur check)"
-              i (ppterm subst t))) 
+              i (ppterm subst t))))
           else
             begin
            (* I do not consider the term associated to ?i in subst since *)
@@ -738,21 +722,21 @@ let delift n subst context metasenv l t =
       (* The reason is that our delift function is weaker than first  *)
       (* order (in the sense of alpha-conversion). See comment above  *)
       (* related to the delift function.                              *)
-(* debug_print "First Order UnificationFailure during delift" ;
-debug_print(sprintf
+(* debug_print (lazy "First Order UnificationFailure during delift") ;
+debug_print(lazy (sprintf
         "Error trying to abstract %s over [%s]: the algorithm only tried to abstract over bound variables"
         (ppterm subst t)
         (String.concat "; "
           (List.map
             (function Some t -> ppterm subst t | None -> "_") l
-          ))); *)
-      raise (Uncertain (sprintf
+          )))); *)
+      raise (Uncertain (lazy (sprintf
         "Error trying to abstract %s over [%s]: the algorithm only tried to abstract over bound variables"
         (ppterm subst t)
         (String.concat "; "
           (List.map
             (function Some t -> ppterm subst t | None -> "_")
-            l))))
+            l)))))
    in
    let (metasenv, subst) = restrict subst !to_be_restricted metasenv in
     res, metasenv, subst
@@ -761,77 +745,139 @@ debug_print(sprintf
 (* delifts a term t of n levels strating from k, that is changes (Rel m)
  * to (Rel (m - n)) when m > (k + n). if k <= m < k + n delift fails
  *)
-let delift_rels_from k n =
- let rec liftaux k =
+let delift_rels_from subst metasenv k n =
+ let rec liftaux subst metasenv k =
   let module C = Cic in
    function
       C.Rel m ->
        if m < k then
-        C.Rel m
+        C.Rel m, subst, metasenv
        else if m < k + n then
          raise DeliftingARelWouldCaptureAFreeVariable
        else
-        C.Rel (m - n)
+        C.Rel (m - n), subst, metasenv
     | C.Var (uri,exp_named_subst) ->
-       let exp_named_subst' = 
-        List.map (function (uri,t) -> (uri,liftaux k t)) exp_named_subst
+       let exp_named_subst',subst,metasenv = 
+        List.fold_right
+         (fun (uri,t) (l,subst,metasenv) ->
+           let t',subst,metasenv = liftaux subst metasenv k t in
+            (uri,t')::l,subst,metasenv) exp_named_subst ([],subst,metasenv)
        in
-        C.Var (uri,exp_named_subst')
+        C.Var (uri,exp_named_subst'),subst,metasenv
     | C.Meta (i,l) ->
-       let l' =
-        List.map
-         (function
-             None -> None
-           | Some t -> Some (liftaux k t)
-         ) l
-       in
-        C.Meta(i,l')
-    | C.Sort _ as t -> t
-    | C.Implicit _ as t -> t
-    | C.Cast (te,ty) -> C.Cast (liftaux k te, liftaux k ty)
-    | C.Prod (n,s,t) -> C.Prod (n, liftaux k s, liftaux (k+1) t)
-    | C.Lambda (n,s,t) -> C.Lambda (n, liftaux k s, liftaux (k+1) t)
-    | C.LetIn (n,s,t) -> C.LetIn (n, liftaux k s, liftaux (k+1) t)
-    | C.Appl l -> C.Appl (List.map (liftaux k) l)
+        (try
+          let (_, t,_) = lookup_subst i subst in
+           liftaux subst metasenv k (CicSubstitution.subst_meta l t)
+         with CicUtil.Subst_not_found _ -> 
+          let l',to_be_restricted,subst,metasenv =
+           let rec aux con l subst metasenv =
+            match l with
+               [] -> [],[],subst,metasenv
+             | he::tl ->
+                let tl',to_be_restricted,subst,metasenv =
+                 aux (con + 1) tl subst metasenv in
+                let he',more_to_be_restricted,subst,metasenv =
+                 match he with
+                    None -> None,[],subst,metasenv
+                  | Some t ->
+                     try
+                      let t',subst,metasenv = liftaux subst metasenv k t in
+                       Some t',[],subst,metasenv
+                     with
+                      DeliftingARelWouldCaptureAFreeVariable ->
+                       None,[i,con],subst,metasenv
+                in
+                 he'::tl',more_to_be_restricted@to_be_restricted,subst,metasenv
+           in
+            aux 1 l subst metasenv in
+          let metasenv,subst = restrict subst to_be_restricted metasenv in
+           C.Meta(i,l'),subst,metasenv)
+    | C.Sort _ as t -> t,subst,metasenv
+    | C.Implicit _ as t -> t,subst,metasenv
+    | C.Cast (te,ty) ->
+       let te',subst,metasenv = liftaux subst metasenv k te in
+       let ty',subst,metasenv = liftaux subst metasenv k ty in
+        C.Cast (te',ty'),subst,metasenv
+    | C.Prod (n,s,t) ->
+       let s',subst,metasenv = liftaux subst metasenv k s in
+       let t',subst,metasenv = liftaux subst metasenv (k+1) t in
+        C.Prod (n,s',t'),subst,metasenv
+    | C.Lambda (n,s,t) ->
+       let s',subst,metasenv = liftaux subst metasenv k s in
+       let t',subst,metasenv = liftaux subst metasenv (k+1) t in
+        C.Lambda (n,s',t'),subst,metasenv
+    | C.LetIn (n,s,t) ->
+       let s',subst,metasenv = liftaux subst metasenv k s in
+       let t',subst,metasenv = liftaux subst metasenv (k+1) t in
+        C.LetIn (n,s',t'),subst,metasenv
+    | C.Appl l ->
+       let l',subst,metasenv =
+        List.fold_right
+         (fun t (l,subst,metasenv) ->
+           let t',subst,metasenv = liftaux subst metasenv k t in
+            t'::l,subst,metasenv) l ([],subst,metasenv) in
+       C.Appl l',subst,metasenv
     | C.Const (uri,exp_named_subst) ->
-       let exp_named_subst' = 
-        List.map (function (uri,t) -> (uri,liftaux k t)) exp_named_subst
+       let exp_named_subst',subst,metasenv = 
+        List.fold_right
+         (fun (uri,t) (l,subst,metasenv) ->
+           let t',subst,metasenv = liftaux subst metasenv k t in
+            (uri,t')::l,subst,metasenv) exp_named_subst ([],subst,metasenv)
        in
-        C.Const (uri,exp_named_subst')
+        C.Const (uri,exp_named_subst'),subst,metasenv
     | C.MutInd (uri,tyno,exp_named_subst) ->
-       let exp_named_subst' = 
-        List.map (function (uri,t) -> (uri,liftaux k t)) exp_named_subst
+       let exp_named_subst',subst,metasenv = 
+        List.fold_right
+         (fun (uri,t) (l,subst,metasenv) ->
+           let t',subst,metasenv = liftaux subst metasenv k t in
+            (uri,t')::l,subst,metasenv) exp_named_subst ([],subst,metasenv)
        in
-        C.MutInd (uri,tyno,exp_named_subst')
+        C.MutInd (uri,tyno,exp_named_subst'),subst,metasenv
     | C.MutConstruct (uri,tyno,consno,exp_named_subst) ->
-       let exp_named_subst' = 
-        List.map (function (uri,t) -> (uri,liftaux k t)) exp_named_subst
+       let exp_named_subst',subst,metasenv = 
+        List.fold_right
+         (fun (uri,t) (l,subst,metasenv) ->
+           let t',subst,metasenv = liftaux subst metasenv k t in
+            (uri,t')::l,subst,metasenv) exp_named_subst ([],subst,metasenv)
        in
-        C.MutConstruct (uri,tyno,consno,exp_named_subst')
+        C.MutConstruct (uri,tyno,consno,exp_named_subst'),subst,metasenv
     | C.MutCase (sp,i,outty,t,pl) ->
-       C.MutCase (sp, i, liftaux k outty, liftaux k t,
-        List.map (liftaux k) pl)
+       let outty',subst,metasenv = liftaux subst metasenv k outty in
+       let t',subst,metasenv = liftaux subst metasenv k t in
+       let pl',subst,metasenv =
+        List.fold_right
+         (fun t (l,subst,metasenv) ->
+           let t',subst,metasenv = liftaux subst metasenv k t in
+            t'::l,subst,metasenv) pl ([],subst,metasenv)
+       in
+        C.MutCase (sp,i,outty',t',pl'),subst,metasenv
     | C.Fix (i, fl) ->
        let len = List.length fl in
-       let liftedfl =
-        List.map
-         (fun (name, i, ty, bo) -> (name, i, liftaux k ty, liftaux (k+len) bo))
-          fl
+       let liftedfl,subst,metasenv =
+        List.fold_right
+         (fun (name, i, ty, bo) (l,subst,metasenv) ->
+           let ty',subst,metasenv = liftaux subst metasenv k ty in
+           let bo',subst,metasenv = liftaux subst metasenv (k+len) bo in
+            (name,i,ty',bo')::l,subst,metasenv
+         ) fl ([],subst,metasenv)
        in
-        C.Fix (i, liftedfl)
+        C.Fix (i, liftedfl),subst,metasenv
     | C.CoFix (i, fl) ->
        let len = List.length fl in
-       let liftedfl =
-        List.map
-         (fun (name, ty, bo) -> (name, liftaux k ty, liftaux (k+len) bo))
-          fl
+       let liftedfl,subst,metasenv =
+        List.fold_right
+         (fun (name, ty, bo) (l,subst,metasenv) ->
+           let ty',subst,metasenv = liftaux subst metasenv k ty in
+           let bo',subst,metasenv = liftaux subst metasenv (k+len) bo in
+            (name,ty',bo')::l,subst,metasenv
+         ) fl ([],subst,metasenv)
        in
-        C.CoFix (i, liftedfl)
+        C.CoFix (i, liftedfl),subst,metasenv
  in
- liftaux k
+  liftaux subst metasenv k
 
-let delift_rels n t =
-  delift_rels_from 1 n t
+let delift_rels subst metasenv n t =
+  delift_rels_from subst metasenv 1 n t
  
 
 (**** END OF DELIFT ****)
@@ -846,5 +892,5 @@ let fpp_gen ppf s =
 
 let fppsubst ppf subst = fpp_gen ppf (ppsubst subst)
 let fppterm ppf term = fpp_gen ppf (CicPp.ppterm term)
-let fppmetasenv ppf metasenv = fpp_gen ppf (ppmetasenv metasenv [])
+let fppmetasenv ppf metasenv = fpp_gen ppf (ppmetasenv [] metasenv)