src/Tools/Code/code_thingol.ML

     | Dict_Var of { var: vname, index: int, length: int, class: class, unique: bool };
   datatype itype =
       `%% of string * itype list
     | ITyVar of vname;
   type const = { sym: Code_Symbol.T, typargs: itype list, dicts: dict list list,
-    dom: itype list, annotation: itype option };
+    dom: itype list, range: itype, annotation: itype option };
   datatype iterm =
       IConst of const
     | IVar of vname option
     | `$ of iterm * iterm
-    | `|=> of (vname option * itype) * iterm
+    | `|=> of (vname option * itype) * (iterm * itype)
     | ICase of { term: iterm, typ: itype, clauses: (iterm * iterm) list, primitive: iterm };
   val `-> : itype * itype -> itype;
   val `--> : itype list * itype -> itype;
   val `$$ : iterm * iterm list -> iterm;
-  val `|==> : (vname option * itype) list * iterm -> iterm;
+  val `|==> : (vname option * itype) list * (iterm * itype) -> iterm;
   type typscheme = (vname * sort) list * itype;
 end;
 
 signature CODE_THINGOL =
 sig

   val unfoldr: ('a -> ('b * 'a) option) -> 'a -> 'b list * 'a
   val unfold_fun: itype -> itype list * itype
   val unfold_fun_n: int -> itype -> itype list * itype
   val unfold_app: iterm -> iterm * iterm list
   val unfold_abs: iterm -> (vname option * itype) list * iterm
+  val unfold_abs_typed: iterm -> ((vname option * itype) list * (iterm * itype)) option
   val split_let: iterm -> (((iterm * itype) * iterm) * iterm) option
   val split_let_no_pat: iterm -> (((string option * itype) * iterm) * iterm) option
   val unfold_let: iterm -> ((iterm * itype) * iterm) list * iterm
   val unfold_let_no_pat: iterm -> ((string option * itype) * iterm) list * iterm
   val split_pat_abs: iterm -> ((iterm * itype) * iterm) option

     val (tys1, ty1) = unfold_fun ty;
     val (tys3, tys2) = chop n tys1;
   in (tys3, tys2 `--> ty1) end;
 
 type const = { sym: Code_Symbol.T, typargs: itype list, dicts: dict list list,
-  dom: itype list, annotation: itype option };
+  dom: itype list, range: itype, annotation: itype option };
 
 datatype iterm =
     IConst of const
   | IVar of vname option
   | `$ of iterm * iterm
-  | `|=> of (vname option * itype) * iterm
+  | `|=> of (vname option * itype) * (iterm * itype)
   | ICase of { term: iterm, typ: itype, clauses: (iterm * iterm) list, primitive: iterm };
     (*see also signature*)
 
 fun is_IVar (IVar _) = true
   | is_IVar _ = false;
 
 fun is_IAbs (_ `|=> _) = true
   | is_IAbs _ = false;
 
 val op `$$ = Library.foldl (op `$);
-val op `|==> = Library.foldr (op `|=>);
+fun vs_tys `|==> body = Library.foldr
+  (fn (v_ty as (_, ty), body as (_, rty)) => (v_ty `|=> body, ty `-> rty)) (vs_tys, body)
+  |> fst;
 
 val unfold_app = unfoldl
   (fn op `$ t_t => SOME t_t
     | _ => NONE);
 
 val unfold_abs = unfoldr
-  (fn op `|=> v_t => SOME v_t
+  (fn (v `|=> (t, _)) => SOME (v, t)
     | _ => NONE);
+
+fun unfold_abs_typed (v_ty `|=> body) =
+      unfoldr
+        (fn (v_ty `|=> body, _) => SOME (v_ty, body)
+          | _ => NONE) body
+      |> apfst (cons v_ty)
+      |> SOME
+  | unfold_abs_typed _ = NONE
 
 fun split_let (ICase { term = t, typ = ty, clauses = [(p, body)], ... }) =
       SOME (((p, ty), t), body)
   | split_let _ = NONE;
 

 fun fold_constexprs f =
   let
     fun fold' (IConst c) = f c
       | fold' (IVar _) = I
       | fold' (t1 `$ t2) = fold' t1 #> fold' t2
-      | fold' (_ `|=> t) = fold' t
+      | fold' (_ `|=> (t, _)) = fold' t
       | fold' (ICase { term = t, clauses = clauses, ... }) =
           fold' t #> fold (fn (p, body) => fold' p #> fold' body) clauses
   in fold' end;
 
 val add_constsyms = fold_constexprs (fn { sym, ... } => insert (op =) sym);

       let
         fun fold_term _ (IConst _) = I
           | fold_term vs (IVar (SOME v)) = if member (op =) vs v then I else f v
           | fold_term _ (IVar NONE) = I
           | fold_term vs (t1 `$ t2) = fold_term vs t1 #> fold_term vs t2
-          | fold_term vs ((SOME v, _) `|=> t) = fold_term (insert (op =) v vs) t
-          | fold_term vs ((NONE, _) `|=> t) = fold_term vs t
+          | fold_term vs ((SOME v, _) `|=> (t, _)) = fold_term (insert (op =) v vs) t
+          | fold_term vs ((NONE, _) `|=> (t, _)) = fold_term vs t
           | fold_term vs (ICase { term = t, clauses = clauses, ... }) =
               fold_term vs t #> fold (fold_clause vs) clauses
         and fold_clause vs (p, t) = fold_term (add_vars p vs) t;
       in fold_term [] end
     fun add_vars t = fold_aux add_vars (insert (op =)) t;

 fun exists_var t v = fold_varnames (fn w => fn b => v = w orelse b) t false;
 
 fun invent_params used tys =
   (map o apfst) SOME (Name.invent_names (Name.build_context used) "a" tys);
 
-fun split_pat_abs ((NONE, ty) `|=> t) = SOME ((IVar NONE, ty), t)
-  | split_pat_abs ((SOME v, ty) `|=> t) = SOME (case t
+fun split_pat_abs ((NONE, ty) `|=> (t, _)) = SOME ((IVar NONE, ty), t)
+  | split_pat_abs ((SOME v, ty) `|=> (t, _)) = SOME (case t
      of ICase { term = IVar (SOME w), clauses = [(p, body)], ... } =>
           if v = w andalso (exists_var p v orelse not (exists_var body v))
           then ((p, ty), body)
           else ((IVar (SOME v), ty), t)
       | _ => ((IVar (SOME v), ty), t))
   | split_pat_abs _ = NONE;
 
 val unfold_pat_abs = unfoldr split_pat_abs;
 
 fun unfold_abs_eta [] t = ([], t)
-  | unfold_abs_eta (_ :: tys) ((v, _) `|=> t) =
+  | unfold_abs_eta (_ :: tys) ((v, _) `|=> (t, _)) =
       let
         val (vs, t') = unfold_abs_eta tys t;
       in (v :: vs, t') end
   | unfold_abs_eta tys t =
       let
         val vs = map fst (invent_params (declare_varnames t) tys);
       in (vs, t `$$ map IVar vs) end;
 
-fun satisfied_application wanted (const as { dom = tys, ... }, ts) =
+fun satisfied_application wanted (const as { dom, range, ... }, ts) =
   let
     val given = length ts;
     val delta = wanted - given;
     val vs_tys = invent_params (fold declare_varnames ts)
-      (((take delta o drop given) tys));
-  in vs_tys `|==> IConst const `$$ ts @ map (IVar o fst) vs_tys end;
+      (((take delta o drop given) dom));
+    val (_, rty) = unfold_fun_n wanted range;
+  in vs_tys `|==> (IConst const `$$ ts @ map (IVar o fst) vs_tys, rty) end;
 
 fun map_terms_bottom_up f (t as IConst _) = f t
   | map_terms_bottom_up f (t as IVar _) = f t
   | map_terms_bottom_up f (t1 `$ t2) = f
       (map_terms_bottom_up f t1 `$ map_terms_bottom_up f t2)
-  | map_terms_bottom_up f ((v, ty) `|=> t) = f
-      ((v, ty) `|=> map_terms_bottom_up f t)
+  | map_terms_bottom_up f ((v, ty) `|=> (t, rty)) = f
+      ((v, ty) `|=> (map_terms_bottom_up f t, rty))
   | map_terms_bottom_up f (ICase { term = t, typ = ty, clauses = clauses, primitive = t0 }) = f
       (ICase { term = map_terms_bottom_up f t, typ = ty,
         clauses = (map o apply2) (map_terms_bottom_up f) clauses,
         primitive = map_terms_bottom_up f t0 });
 

 and exists_dictss_var f dss = (exists o exists) (exists_dict_var f) dss;
 
 fun contains_dict_var (IConst { dicts = dss, ... }) = exists_dictss_var (K true) dss
   | contains_dict_var (IVar _) = false
   | contains_dict_var (t1 `$ t2) = contains_dict_var t1 orelse contains_dict_var t2
-  | contains_dict_var (_ `|=> t) = contains_dict_var t
+  | contains_dict_var (_ `|=> (t, _)) = contains_dict_var t
   | contains_dict_var (ICase { primitive = t, ... }) = contains_dict_var t;
 
 val unambiguous_dictss = not o exists_dictss_var (fn { unique, ... } => not unique);
 
 

       pair (IVar (SOME v))
   | translate_term ctxt algbr eqngr permissive some_thm (Abs (v, ty, t), some_abs) =
       let
         val ((v', _), t') = Term.dest_abs_global (Abs (Name.desymbolize (SOME false) v, ty, t));
         val v'' = if Term.used_free v' t' then SOME v' else NONE
+        val rty = fastype_of_tagged_term t'
       in
         translate_typ ctxt algbr eqngr permissive ty
+        ##>> translate_typ ctxt algbr eqngr permissive rty
         ##>> translate_term ctxt algbr eqngr permissive some_thm (t', some_abs)
-        #>> (fn (ty, t) => (v'', ty) `|=> t)
+        #>> (fn ((ty, rty), t) => (v'', ty) `|=> (t, rty))
       end
   | translate_term ctxt algbr eqngr permissive some_thm (t as _ $ _, some_abs) =
       case strip_comb t
        of (Const (c, ty), ts) =>
             translate_app ctxt algbr eqngr permissive some_thm (((c, ty), ts), some_abs)

     val (dom, range) = Term.strip_type ty';
   in
     ensure_const ctxt algbr eqngr permissive c
     ##>> fold_map (translate_typ ctxt algbr eqngr permissive) typargs
     ##>> fold_map (translate_dicts ctxt algbr eqngr permissive some_thm) (typargs ~~ sorts)
-    ##>> fold_map (translate_typ ctxt algbr eqngr permissive) (ty' :: dom)
-    #>> (fn (((c, typargs), dss), annotation :: dom) =>
+    ##>> fold_map (translate_typ ctxt algbr eqngr permissive) (range :: dom)
+    #>> (fn (((c, typargs), dss), range :: dom) =>
       IConst { sym = Constant c, typargs = typargs, dicts = dss,
-        dom = dom, annotation =
-          if annotate then SOME annotation else NONE })
+        dom = dom, range = range, annotation =
+          if annotate then SOME (dom `--> range) else NONE })
   end
 and translate_app_const ctxt algbr eqngr permissive some_thm ((c_ty, ts), some_abs) =
   translate_const ctxt algbr eqngr permissive some_thm (c_ty, some_abs)
   ##>> fold_map (translate_term ctxt algbr eqngr permissive some_thm o rpair NONE) ts
   #>> (fn (t, ts) => t `$$ ts)

       val given = length ts;
       val delta = wanted - given;
       val tys = (take delta o drop given o binder_types) ty;
       val used = Name.build_context ((fold o fold_aterms) Term.declare_term_frees ts);
       val vs_tys = Name.invent_names used "a" tys;
+      val rty = (drop delta o binder_types) ty ---> body_type ty;
     in
       fold_map (translate_typ ctxt algbr eqngr permissive) tys
       ##>> translate_case ctxt algbr eqngr permissive some_thm pattern_schema ((c, ty), ts @ map Free vs_tys)
-      #>> (fn (tys, t) => map2 (fn (v, _) => pair (SOME v)) vs_tys tys `|==> t)
+      ##>> translate_typ ctxt algbr eqngr permissive rty
+      #>> (fn ((tys, t), rty) => map2 (fn (v, _) => pair (SOME v)) vs_tys tys `|==> (t, rty))
     end
   else if length ts > wanted then
     translate_case ctxt algbr eqngr permissive some_thm pattern_schema ((c, ty), take wanted ts)
     ##>> fold_map (translate_term ctxt algbr eqngr permissive some_thm o rpair NONE) (drop wanted ts)
     #>> (fn (t, ts) => t `$$ ts)