New syntax and semantics for the rewriting steps that make the pretty-printed

[helm.git] / components / tactics / declarative.ml

diff --git a/components/tactics/declarative.ml b/components/tactics/declarative.ml
index 7e276a8bcef73f63b273e9ed00ae3f61541f7d09..77276d92909866cfcba3c458c10f99eccc32f472 100644 (file)
--- a/components/tactics/declarative.ml
+++ b/components/tactics/declarative.ml
@@ -134,10 +134,10 @@ let existselim t id1 t1 id2 t2 =
 
 let andelim = existselim;;
 
-let rewritingstep ~dbd ~universe lhs rhs just conclude =
+let rewritingstep ~dbd ~universe lhs rhs just last_step =
  let aux ((proof,goal) as status) =
   let (curi,metasenv,proofbo,proofty) = proof in
-  let _,context,_ = CicUtil.lookup_meta goal metasenv in
+  let _,context,gty = CicUtil.lookup_meta goal metasenv in
   let eq,trans =
    match LibraryObjects.eq_URI () with
       None -> raise (ProofEngineTypes.Fail (lazy "You need to register the default equality first. Please use the \"default\" command"))
@@ -161,68 +161,66 @@ let rewritingstep ~dbd ~universe lhs rhs just conclude =
          Tactics.auto ~dbd ~params ~universe
     | `Term just -> Tactics.apply just 
   in
-   match lhs with
-      None ->
-       let plhs,prhs =
-        match 
-         fst
-          (CicTypeChecker.type_of_aux' metasenv context (Cic.Rel 1)
-            CicUniv.empty_ugraph)
-        with
-           Cic.Appl [_;_;plhs;prhs] -> plhs,prhs
-         | _ -> assert false in
-       let last_hyp_name =
-        match context with
-           (Some (Cic.Name id,_))::_ -> id
-         | _ -> assert false
-       in
-        (match conclude with
-            None ->
-             ProofEngineTypes.apply_tactic
-              (Tacticals.thens
-                ~start:(Tactics.apply ~term:trans)
-                ~continuations:
-                  [ Tactics.apply prhs ;
-                    Tactics.apply (Cic.Rel 1) ;
-                    Tacticals.then_
-                     ~start:(Tactics.clear ~hyps:[last_hyp_name])
-                     ~continuation:just]) status
-          | Some name ->
-             let mk_fresh_name_callback =
-             fun metasenv context _ ~typ ->
-               FreshNamesGenerator.mk_fresh_name ~subst:[]
-                metasenv context name ~typ
-            in
-              ProofEngineTypes.apply_tactic
-               (Tacticals.thens
-                 ~start:(Tactics.cut ~mk_fresh_name_callback
-                 (Cic.Appl [eq ; ty ; plhs ; rhs]))
-                 ~continuations:
-                   [ Tactics.clear ~hyps:[last_hyp_name] ;
-                     Tacticals.thens
-                      ~start:(Tactics.apply ~term:trans)
-                      ~continuations:
-                        [ Tactics.apply prhs ;
-                          Tactics.apply (Cic.Rel 1) ;
-                          Tacticals.then_
-                           ~start:(Tactics.clear ~hyps:[last_hyp_name])
-                           ~continuation:just]
-                   ]) status)
-    | Some lhs ->
-       match conclude with
-          None -> ProofEngineTypes.apply_tactic just status
-        | Some name ->
+   let plhs,prhs,prepare =
+    match lhs with
+       None ->
+        let plhs,prhs =
+         match gty with 
+            Cic.Appl [_;_;plhs;prhs] -> plhs,prhs
+          | _ -> assert false
+        in
+         plhs,prhs,
+          (fun continuation ->
+            ProofEngineTypes.apply_tactic continuation status)
+     | Some (None,lhs) ->
+        let plhs,prhs =
+         match gty with 
+            Cic.Appl [_;_;plhs;prhs] -> plhs,prhs
+          | _ -> assert false
+        in
+         (*CSC: manca check plhs convertibile con lhs *)
+         plhs,prhs,
+          (fun continuation ->
+            ProofEngineTypes.apply_tactic continuation status)
+     | Some (Some name,lhs) ->
+        let newmeta = CicMkImplicit.new_meta metasenv [] in
+        let irl =
+         CicMkImplicit.identity_relocation_list_for_metavariable context in
+        let plhs = lhs in
+        let prhs = Cic.Meta(newmeta,irl) in
+         plhs,prhs,
+          (fun continuation ->
+            let metasenv = (newmeta, context, ty)::metasenv in
             let mk_fresh_name_callback =
-            fun metasenv context _ ~typ ->
-              FreshNamesGenerator.mk_fresh_name ~subst:[]
-               metasenv context name ~typ
+             fun metasenv context _ ~typ ->
+             FreshNamesGenerator.mk_fresh_name ~subst:[] metasenv context
+               (Cic.Name name) ~typ
            in
+            let proof = curi,metasenv,proofbo,proofty in
+            let proof,goals =
              ProofEngineTypes.apply_tactic
               (Tacticals.thens
-                ~start:
-                  (Tactics.cut ~mk_fresh_name_callback
-                    (Cic.Appl [eq ; ty ; lhs ; rhs]))
-                ~continuations:[ Tacticals.id_tac ; just ]) status
+                ~start:(Tactics.cut ~mk_fresh_name_callback
+                 (Cic.Appl [eq ; ty ; lhs ; prhs]))
+                ~continuations:[Tacticals.id_tac ; continuation]) (proof,goal)
+            in
+             let goals =
+              match goals with
+                 [g1;g2] -> [g2;newmeta;g1]
+               | _ -> assert false
+             in
+              proof,goals)
+   in
+    let continuation =
+     if last_step then
+      (*CSC:manca controllo sul fatto che rhs sia convertibile con prhs*)
+      just
+     else
+      Tacticals.thens
+       ~start:(Tactics.apply ~term:(Cic.Appl [trans;ty;plhs;rhs;prhs]))
+       ~continuations:[just ; Tacticals.id_tac]
+    in
+     prepare continuation
  in
   ProofEngineTypes.mk_tactic aux
 ;;