generalized code

--- a/src/HOL/Tools/BNF/bnf_gfp_rec_sugar.ML	Tue Apr 07 15:14:12 2015 +0200
+++ b/src/HOL/Tools/BNF/bnf_gfp_rec_sugar.ML	Tue Apr 07 15:14:14 2015 +0200
@@ -51,7 +51,8 @@
   val massage_let_if_case: Proof.context -> (term -> bool) -> (typ list -> term -> term) ->
     typ list -> term -> term
   val massage_nested_corec_call: Proof.context -> (term -> bool) ->
-    (typ list -> typ -> typ -> term -> term) -> typ list -> typ -> term -> term
+    (typ list -> typ -> typ -> term -> term) -> (typ -> typ -> term) -> typ list -> typ -> term ->
+    term
   val expand_to_ctr_term: Proof.context -> string -> typ list -> term -> term
   val massage_corec_code_rhs: Proof.context -> (typ list -> term -> term list -> term) ->
     typ list -> term -> term
@@ -305,17 +306,15 @@
 
 fun curried_type (Type (@{type_name fun}, [Type (@{type_name prod}, Ts), T])) = Ts ---> T;
 
-fun massage_nested_corec_call ctxt has_call raw_massage_call bound_Ts U t0 =
+fun massage_nested_corec_call ctxt has_call massage_call wrap_noncall bound_Ts U t0 =
   let
     fun check_no_call t = if has_call t then unexpected_corec_call ctxt [t0] t else ();
 
-    val build_map_Inl = build_map ctxt [] (uncurry Inl_const o dest_sumT o snd);
-
     fun massage_mutual_call bound_Ts (Type (@{type_name fun}, [_, U2]))
         (Type (@{type_name fun}, [T1, T2])) t =
         Abs (Name.uu, T1, massage_mutual_call bound_Ts U2 T2 (incr_boundvars 1 t $ Bound 0))
       | massage_mutual_call bound_Ts U T t =
-        if has_call t then raw_massage_call bound_Ts T U t else build_map_Inl (T, U) $ t;
+        if has_call t then massage_call bound_Ts T U t else wrap_noncall T U $ t;
 
     fun massage_map bound_Ts (Type (_, Us)) (Type (s, Ts)) t =
         (case try (dest_map ctxt s) t of
@@ -345,9 +344,10 @@
           val j = Term.maxidx_of_term t + 1;
           val var = Var ((Name.uu, j), domain_type (fastype_of1 (bound_Ts, t)));
         in
-          Term.lambda var (Term.incr_boundvars 1 (massage_call bound_Ts U T (betapply (t, var))))
+          Term.lambda var (Term.incr_boundvars 1 (massage_any_call bound_Ts U T
+            (betapply (t, var))))
         end)
-    and massage_call bound_Ts U T =
+    and massage_any_call bound_Ts U T =
       massage_let_if_case ctxt has_call (fn bound_Ts => fn t =>
         if has_call t then
           (case U of
@@ -361,7 +361,7 @@
                 val arg_Ts = map typof args;
               in
                 Term.list_comb (f',
-                  @{map 3} (massage_call bound_Ts) (binder_types f'_T) arg_Ts args)
+                  @{map 3} (massage_any_call bound_Ts) (binder_types f'_T) arg_Ts args)
               end
             | NONE =>
               (case t of
@@ -370,7 +370,7 @@
                   val U' = curried_type U;
                   val T' = curried_type T;
                 in
-                  Const (@{const_name case_prod}, U' --> U) $ massage_call bound_Ts U' T' t'
+                  Const (@{const_name case_prod}, U' --> U) $ massage_any_call bound_Ts U' T' t'
                 end
               | t1 $ t2 =>
                 (if has_call t2 then
@@ -379,15 +379,15 @@
                   massage_map bound_Ts U T t1 $ t2
                   handle NO_MAP _ => massage_mutual_call bound_Ts U T t)
               | Abs (s, T', t') =>
-                Abs (s, T', massage_call (T' :: bound_Ts) (range_type U) (range_type T) t')
+                Abs (s, T', massage_any_call (T' :: bound_Ts) (range_type U) (range_type T) t')
               | _ => massage_mutual_call bound_Ts U T t))
           | _ => ill_formed_corec_call ctxt t)
         else
-          build_map_Inl (T, U) $ t) bound_Ts;
+          wrap_noncall T U $ t) bound_Ts;
 
     val T = fastype_of1 (bound_Ts, t0);
   in
-    if has_call t0 then massage_call bound_Ts U T t0 else build_map_Inl (T, U) $ t0
+    if has_call t0 then massage_any_call bound_Ts U T t0 else wrap_noncall T U $ t0
   end;
 
 fun expand_to_ctr_term ctxt s Ts t =
@@ -894,7 +894,7 @@
     NONE => I
   | SOME {fun_args, rhs_term, ...} =>
     let
-      fun massage_leaf bound_Ts T U t0 =
+      fun massage_call bound_Ts T U t0 =
         let
           val U2 =
             (case try dest_sumT U of
@@ -919,11 +919,14 @@
             rewrite bound_Ts t0
           end;
 
+      fun wrap_noncall T U = build_map ctxt [] (uncurry Inl_const o dest_sumT o snd) (T, U);
+
       val bound_Ts = List.rev (map fastype_of fun_args);
 
       fun build t =
         rhs_term
-        |> massage_nested_corec_call ctxt has_call massage_leaf bound_Ts (range_type (fastype_of t))
+        |> massage_nested_corec_call ctxt has_call massage_call wrap_noncall bound_Ts
+          (range_type (fastype_of t))
         |> abs_tuple_balanced fun_args;
     in
       build