X-Git-Url: http://matita.cs.unibo.it/gitweb/?a=blobdiff_plain;f=helm%2Focaml%2Ftactics%2FproofEngineHelpers.ml;h=ea797481c4edf96b0f550f60fa0c9fb9cc6e510b;hb=b84c60ff48a21a62a08e636f32cf0df46dfbe45a;hp=03257dfa1bf46cdbd0563208d2170237e176fa1b;hpb=7ec7262cfa317c1962164350361f82a56c5d1826;p=helm.git

diff --git a/helm/ocaml/tactics/proofEngineHelpers.ml b/helm/ocaml/tactics/proofEngineHelpers.ml
index 03257dfa1..ea797481c 100644
--- a/helm/ocaml/tactics/proofEngineHelpers.ml
+++ b/helm/ocaml/tactics/proofEngineHelpers.ml
@@ -23,13 +23,19 @@
  * http://cs.unibo.it/helm/.
  *)
 
+exception Bad_pattern of string
+
 let new_meta_of_proof ~proof:(_, metasenv, _, _) =
   CicMkImplicit.new_meta metasenv []
 
 let subst_meta_in_proof proof meta term newmetasenv =
  let uri,metasenv,bo,ty = proof in
-    (* empty context is ok for term since it wont be used by apply_subst *)
-  let subst_in = CicMetaSubst.apply_subst [meta,([], term)] in
+   (* empty context is ok for term since it wont be used by apply_subst *)
+   (* hack: since we do not know the context and the type of term, we
+      create a substitution with cc =[] and type = Implicit; they will be
+      in  any case dropped by apply_subst, but it would be better to rewrite
+      the code. Cannot we just use apply_subst_metasenv, etc. ?? *)
+  let subst_in = CicMetaSubst.apply_subst [meta,([], term,Cic.Implicit None)] in
    let metasenv' =
     newmetasenv @ (List.filter (function (m,_,_) -> m <> meta) metasenv)
    in
@@ -103,3 +109,372 @@ let compare_metasenvs ~oldmetasenv ~newmetasenv =
    (function (i,_,_) ->
      not (List.exists (fun (j,_,_) -> i=j) oldmetasenv)) newmetasenv)
 ;;
+
+(** finds the _pointers_ to subterms that are alpha-equivalent to wanted in t *)
+let find_subterms ~wanted ~context t =
+  let rec find context w t =
+    if ProofEngineReduction.alpha_equivalence w t then 
+      [context,t]
+    else
+      match t with
+      | Cic.Sort _ 
+      | Cic.Rel _ -> []
+      | Cic.Meta (_, ctx) -> 
+          List.fold_left (
+            fun acc e -> 
+              match e with 
+              | None -> acc 
+              | Some t -> find context w t @ acc
+          ) [] ctx
+      | Cic.Lambda (name, t1, t2) 
+      | Cic.Prod (name, t1, t2) ->
+          find context w t1 @
+          find (Some (name, Cic.Decl t1)::context)
+           (CicSubstitution.lift 1 w) t2
+      | Cic.LetIn (name, t1, t2) -> 
+          find context w t1 @
+          find (Some (name, Cic.Def (t1,None))::context)
+           (CicSubstitution.lift 1 w) t2
+      | Cic.Appl l -> 
+          List.fold_left (fun acc t -> find context w t @ acc) [] l
+      | Cic.Cast (t, ty) -> find context w t @ find context w ty
+      | Cic.Implicit _ -> assert false
+      | Cic.Const (_, esubst)
+      | Cic.Var (_, esubst) 
+      | Cic.MutInd (_, _, esubst) 
+      | Cic.MutConstruct (_, _, _, esubst) -> 
+          List.fold_left (fun acc (_, t) -> find context w t @ acc) [] esubst
+      | Cic.MutCase (_, _, outty, indterm, patterns) -> 
+          find context w outty @ find context w indterm @ 
+            List.fold_left (fun acc p -> find context w p @ acc) [] patterns
+      | Cic.Fix (_, funl) -> 
+         let tys =
+          List.map (fun (n,_,ty,_) -> Some (Cic.Name n,(Cic.Decl ty))) funl
+         in
+          List.fold_left (
+            fun acc (_, _, ty, bo) ->
+             find context w ty @ find (tys @ context) w bo @ acc
+          ) [] funl
+      | Cic.CoFix (_, funl) ->
+         let tys =
+          List.map (fun (n,ty,_) -> Some (Cic.Name n,(Cic.Decl ty))) funl
+         in
+          List.fold_left (
+            fun acc (_, ty, bo) ->
+             find context w ty @ find (tys @ context) w bo @ acc
+          ) [] funl
+  in
+  find context wanted t
+  
+let select_in_term ~context ~term ~pattern:(wanted,where) =
+  let add_ctx context name entry =
+      (Some (name, entry)) :: context
+  in
+  let rec aux context where term =
+    match (where, term) with
+    | Cic.Implicit (Some `Hole), t -> [context,t]
+    | Cic.Implicit (Some `Type), t -> []
+    | Cic.Implicit None,_ -> []
+    | Cic.Meta (_, ctxt1), Cic.Meta (_, ctxt2) ->
+        List.concat
+          (List.map2
+            (fun t1 t2 ->
+              (match (t1, t2) with
+                  Some t1, Some t2 -> aux context t1 t2
+                | _ -> []))
+            ctxt1 ctxt2)
+    | Cic.Cast (te1, ty1), Cic.Cast (te2, ty2) ->
+       aux context te1 te2 @ aux context ty1 ty2
+    | Cic.Prod (Cic.Anonymous, s1, t1), Cic.Prod (name, s2, t2)
+    | Cic.Lambda (Cic.Anonymous, s1, t1), Cic.Lambda (name, s2, t2) ->
+        aux context s1 s2 @ aux (add_ctx context name (Cic.Decl s2)) t1 t2
+    | Cic.Prod (Cic.Name n1, s1, t1), 
+      Cic.Prod ((Cic.Name n2) as name , s2, t2)
+    | Cic.Lambda (Cic.Name n1, s1, t1), 
+      Cic.Lambda ((Cic.Name n2) as name, s2, t2) when n1 = n2->
+        aux context s1 s2 @ aux (add_ctx context name (Cic.Decl s2)) t1 t2
+    | Cic.Prod (name1, s1, t1), Cic.Prod (name2, s2, t2)
+    | Cic.Lambda (name1, s1, t1), Cic.Lambda (name2, s2, t2) -> []
+    | Cic.LetIn (Cic.Anonymous, s1, t1), Cic.LetIn (name, s2, t2) -> 
+        aux context s1 s2 @ aux (add_ctx context name (Cic.Def (s2,None))) t1 t2
+    | Cic.LetIn (Cic.Name n1, s1, t1), 
+      Cic.LetIn ((Cic.Name n2) as name, s2, t2) when n1 = n2-> 
+        aux context s1 s2 @ aux (add_ctx context name (Cic.Def (s2,None))) t1 t2
+    | Cic.LetIn (name1, s1, t1), Cic.LetIn (name2, s2, t2) -> []
+    | Cic.Appl terms1, Cic.Appl terms2 -> auxs context terms1 terms2
+    | Cic.Var (_, subst1), Cic.Var (_, subst2)
+    | Cic.Const (_, subst1), Cic.Const (_, subst2)
+    | Cic.MutInd (_, _, subst1), Cic.MutInd (_, _, subst2)
+    | Cic.MutConstruct (_, _, _, subst1), Cic.MutConstruct (_, _, _, subst2) ->
+        auxs context (List.map snd subst1) (List.map snd subst2)
+    | Cic.MutCase (_, _, out1, t1, pat1), Cic.MutCase (_ , _, out2, t2, pat2) ->
+        aux context out1 out2 @ aux context t1 t2 @ auxs context pat1 pat2
+    | Cic.Fix (_, funs1), Cic.Fix (_, funs2) ->
+       let tys =
+        List.map (fun (n,_,ty,_) -> Some (Cic.Name n,(Cic.Decl ty))) funs2
+       in
+        List.concat
+          (List.map2
+            (fun (_, _, ty1, bo1) (_, _, ty2, bo2) -> 
+              aux context ty1 ty2 @ aux (tys @ context) bo1 bo2)
+            funs1 funs2)
+    | Cic.CoFix (_, funs1), Cic.CoFix (_, funs2) ->
+       let tys =
+        List.map (fun (n,ty,_) -> Some (Cic.Name n,(Cic.Decl ty))) funs2
+       in
+        List.concat
+          (List.map2
+            (fun (_, ty1, bo1) (_, ty2, bo2) ->
+              aux context ty1 ty2 @ aux (tys @ context) bo1 bo2)
+            funs1 funs2)
+    | x,y -> 
+        raise (Bad_pattern 
+                (Printf.sprintf "Pattern %s versus term %s" 
+                  (CicPp.ppterm x)
+                  (CicPp.ppterm y)))
+  and auxs context terms1 terms2 =  (* as aux for list of terms *)
+    List.concat (List.map2 (fun t1 t2 -> aux context t1 t2) terms1 terms2)
+  in
+   let context_len = List.length context in
+   let roots = aux context where term in
+    match wanted with
+       None -> roots
+     | Some wanted ->
+        let rec find_in_roots =
+         function
+            [] -> []
+          | (context',where)::tl ->
+             let tl' = find_in_roots tl in
+             let context'_len = List.length context' in
+             let found =
+              let wanted =
+               CicSubstitution.lift (context'_len - context_len) wanted
+              in
+               find_subterms ~wanted ~context where
+             in
+              found @ tl'
+        in
+         find_in_roots roots
+
+(** create a pattern from a term and a list of subterms.
+* the pattern is granted to have a ? for every subterm that has no selected
+* subterms
+* @param equality equality function used while walking the term. Defaults to
+* physical equality (==) *)
+let pattern_of ?(equality=(==)) ~term terms =
+  let (===) x y = equality x y in
+  let not_found = false, Cic.Implicit None in
+  let rec aux t =
+    match t with
+    | t when List.exists (fun t' -> t === t') terms ->
+       true,Cic.Implicit (Some `Hole)
+    | Cic.Var (uri, subst) ->
+       let b,subst = aux_subst subst in
+        if b then
+         true,Cic.Var (uri, subst)
+        else
+         not_found
+    | Cic.Meta (i, ctxt) ->
+        let b,ctxt =
+          List.fold_right
+           (fun e (b,ctxt) ->
+             match e with
+                None -> b,None::ctxt
+              | Some t -> let bt,t = aux t in b||bt ,Some t::ctxt
+           ) ctxt (false,[])
+        in
+         if b then
+          true,Cic.Meta (i, ctxt)
+         else
+          not_found
+    | Cic.Cast (te, ty) ->
+       let b1,te = aux te in
+       let b2,ty = aux ty in
+        if b1||b2 then true,Cic.Cast (te, ty)
+        else
+         not_found
+    | Cic.Prod (name, s, t) ->
+       let b1,s = aux s in
+       let b2,t = aux t in
+        if b1||b2 then
+         true, Cic.Prod (name, s, t)
+        else
+         not_found
+    | Cic.Lambda (name, s, t) ->
+       let b1,s = aux s in
+       let b2,t = aux t in
+        if b1||b2 then
+         true, Cic.Lambda (name, s, t)
+        else
+         not_found
+    | Cic.LetIn (name, s, t) ->
+       let b1,s = aux s in
+       let b2,t = aux t in
+        if b1||b2 then
+         true, Cic.LetIn (name, s, t)
+        else
+         not_found
+    | Cic.Appl terms ->
+       let b,terms =
+        List.fold_right
+         (fun t (b,terms) ->
+           let bt,t = aux t in
+            b||bt,t::terms
+         ) terms (false,[])
+       in
+        if b then
+         true,Cic.Appl terms
+        else
+         not_found
+    | Cic.Const (uri, subst) ->
+       let b,subst = aux_subst subst in
+        if b then
+         true, Cic.Const (uri, subst)
+        else
+         not_found
+    | Cic.MutInd (uri, tyno, subst) ->
+       let b,subst = aux_subst subst in
+        if b then
+         true, Cic.MutInd (uri, tyno, subst)
+        else
+         not_found
+    | Cic.MutConstruct (uri, tyno, consno, subst) ->
+       let b,subst = aux_subst subst in
+        if b then
+         true, Cic.MutConstruct (uri, tyno, consno, subst)
+        else
+         not_found
+    | Cic.MutCase (uri, tyno, outty, t, pat) ->
+       let b1,outty = aux outty in
+       let b2,t = aux t in
+       let b3,pat =
+        List.fold_right
+         (fun t (b,pat) ->
+           let bt,t = aux t in
+            bt||b,t::pat
+         ) pat (false,[])
+       in
+        if b1 || b2 || b3 then
+         true, Cic.MutCase (uri, tyno, outty, t, pat)
+        else
+         not_found
+    | Cic.Fix (funno, funs) ->
+        let b,funs =
+          List.fold_right
+           (fun (name, i, ty, bo) (b,funs) ->
+             let b1,ty = aux ty in
+             let b2,bo = aux bo in
+              b||b1||b2, (name, i, ty, bo)::funs) funs (false,[])
+        in
+         if b then
+          true, Cic.Fix (funno, funs)
+         else
+          not_found
+    | Cic.CoFix (funno, funs) ->
+        let b,funs =
+          List.fold_right
+           (fun (name, ty, bo) (b,funs) ->
+             let b1,ty = aux ty in
+             let b2,bo = aux bo in
+              b||b1||b2, (name, ty, bo)::funs) funs (false,[])
+        in
+         if b then
+          true, Cic.CoFix (funno, funs)
+         else
+          not_found
+    | Cic.Rel _
+    | Cic.Sort _
+    | Cic.Implicit _ -> not_found
+  and aux_subst subst =
+    List.fold_right
+     (fun (uri, t) (b,subst) ->
+       let b1,t = aux t in
+        b||b1,(uri, t)::subst) subst (false,[])
+  in
+   snd (aux term)
+
+exception Fail of string
+
+  (** select metasenv conjecture pattern
+  * select all subterms of [conjecture] matching [pattern].
+  * It returns the set of matched terms (that can be compared using physical
+  * equality to the subterms of [conjecture]) together with their contexts.
+  * The representation of the set mimics the ProofEngineTypes.pattern type:
+  * a list of hypothesis (names of) together with the list of its matched
+  * subterms (and their contexts) + the list of matched subterms of the
+  * with their context conclusion. Note: in the result the list of hypothesis
+  * has an entry for each entry in the context and in the same order.
+  * Of course the list of terms (with their context) associated to the
+  * hypothesis name may be empty. *)
+  let select ~metasenv ~conjecture:(_,context,ty) ~pattern:(what,hyp_patterns,goal_pattern) =
+   let find_pattern_for name =
+     try Some (snd (List.find (fun (n, pat) -> Cic.Name n = name) hyp_patterns))
+     with Not_found -> None in
+   let ty_terms = select_in_term ~context ~term:ty ~pattern:(what,goal_pattern) in
+   let context_len = List.length context in
+   let context_terms =
+    fst
+     (List.fold_right
+      (fun entry (res,context) ->
+        match entry with
+          None -> (None::res),(None::context)
+        | Some (name,Cic.Decl term) ->
+            (match find_pattern_for name with
+            | None -> ((Some (`Decl []))::res),(entry::context)
+            | Some pat ->
+               try
+                let what =
+                 match what with
+                    None -> None
+                  | Some what ->
+                     let what,subst',metasenv' =
+                      CicMetaSubst.delift_rels [] metasenv
+                       (context_len - List.length context) what
+                     in
+                      assert (subst' = []);
+                      assert (metasenv' = metasenv);
+                      Some what in
+                let terms = select_in_term ~context ~term ~pattern:(what,pat) in
+                 ((Some (`Decl terms))::res),(entry::context)
+               with
+                CicMetaSubst.DeliftingARelWouldCaptureAFreeVariable ->
+                 raise
+                  (Fail
+                    ("The term the user wants to convert is not closed " ^
+                     "in the context of the position of the substitution.")))
+        | Some (name,Cic.Def (bo, ty)) ->
+            (match find_pattern_for name with
+            | None ->
+               let selected_ty= match ty with None -> None | Some _ -> Some [] in
+                ((Some (`Def ([],selected_ty)))::res),(entry::context)
+            | Some pat -> 
+               try
+                let what =
+                 match what with
+                    None -> None
+                  | Some what ->
+                     let what,subst',metasenv' =
+                      CicMetaSubst.delift_rels [] metasenv
+                       (context_len - List.length context) what
+                     in
+                      assert (subst' = []);
+                      assert (metasenv' = metasenv);
+                      Some what in
+                let terms_bo =
+                 select_in_term ~context ~term:bo ~pattern:(what,pat) in
+                let terms_ty =
+                 match ty with
+                    None -> None
+                  | Some ty ->
+                     Some (select_in_term ~context ~term:ty ~pattern:(what,pat))
+                in
+                 ((Some (`Def (terms_bo,terms_ty)))::res),(entry::context)
+               with
+                CicMetaSubst.DeliftingARelWouldCaptureAFreeVariable ->
+                 raise
+                  (Fail
+                    ("The term the user wants to convert is not closed " ^
+                     "in the context of the position of the substitution.")))
+      ) context ([],[]))
+   in
+    context_terms, ty_terms