X-Git-Url: http://matita.cs.unibo.it/gitweb/?a=blobdiff_plain;f=helm%2Focaml%2Fcic_unification%2FcicMetaSubst.ml;h=dfa47e469bbd97d12ddbf6e83ce39935bd90c526;hb=656cb59b98db21ef50afef7677ae03282bd8aad1;hp=768255a1493db265c087ecad4355b934d8354b19;hpb=8f4d1ba2e39207fd2c09108bd777c5cee499fd1c;p=helm.git

diff --git a/helm/ocaml/cic_unification/cicMetaSubst.ml b/helm/ocaml/cic_unification/cicMetaSubst.ml
index 768255a14..dfa47e469 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 _ -> ()
@@ -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
@@ -356,7 +334,7 @@ let ppsubst 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) ->
@@ -558,10 +536,10 @@ 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 +567,16 @@ 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 +592,8 @@ 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 +623,10 @@ 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 +640,9 @@ 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 +716,21 @@ 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
@@ -908,5 +886,5 @@ 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)