X-Git-Url: http://matita.cs.unibo.it/gitweb/?a=blobdiff_plain;f=ocaml%2Fnum.ml;h=8ecf12491be1d9931dfdc39fbbe4c9403f391008;hb=5a57b32e5e068d05c1feb7455861bc8d5e4bd05a;hp=c88fa8de1a666cd68cbb8d1e5c10286fd38157f5;hpb=eba0d24f94f4ab4744d3c9a0ddf4af267cd908ce;p=fireball-separation.git

diff --git a/ocaml/num.ml b/ocaml/num.ml
index c88fa8d..8ecf124 100644
--- a/ocaml/num.ml
+++ b/ocaml/num.ml
@@ -92,14 +92,23 @@ let free_vars = (List.map fst) ++ free_vars';;
 module ToScott =
 struct
 
+let delta = let open Pure in L(A(V 0, V 0))
+
+let bomb = ref(`Var(-1, -666));;
+
 let rec t_of_i_num_var =
  function
   | `N n -> Scott.mk_n n
-  | `Var(v,_) -> Pure.V v
+  | `Var(v,_) as x -> assert (x <> !bomb); Pure.V v
   | `Match(t,_,liftno,bs,args) ->
-      let bs = List.map (fun (n,t) -> n, t_of_nf (lift liftno t)) !bs in
+      let bs = List.map (
+        function (n,t) -> n,
+         (if t = !bomb then delta
+          else L (t_of_nf (lift (liftno+1) t)))
+        ) !bs in
       let t = t_of_i_num_var t in
       let m = Scott.mk_match t bs in
+      let m = Pure.A(m,delta) in
       List.fold_left (fun acc t -> Pure.A(acc,t_of_nf t)) m args
   | `I((v,_), args) -> Listx.fold_left (fun acc t -> Pure.A(acc,t_of_nf t)) (Pure.V v) args
 and t_of_nf =
@@ -112,27 +121,34 @@ end
 
 (************ Pretty-printing ************************************)
 
-let rec string_of_term l =
- let rec string_of_term_w_pars l = function
-  | `Var(n,ar) -> print_name l n ^ ":" ^ string_of_int ar
+(* let rec string_of_term l  = fun _ -> "";; *)
+
+let rec string_of_term =
+ let boundvar x = "v" ^ string_of_int x in
+ let varname lev l n =
+  if n < lev then boundvar (lev-n-1)
+   else if n - lev < List.length l then List.nth l (n-lev)
+    else "`" ^ string_of_int (n-lev) in
+ let rec string_of_term_w_pars lev l  = function
+  | `Var(n,ar) -> varname lev l n ^ (if debug_display_arities then ":" ^ string_of_int ar else "")
   | `N n -> string_of_int n
-  | `I _ as t -> "(" ^ string_of_term_no_pars_app l (t :> nf) ^ ")"
-  | `Lam _ as t -> "(" ^ string_of_term_no_pars_lam l t ^ ")"
+  | `I _ as t -> "(" ^ string_of_term_no_pars_app lev l t ^ ")"
+  | `Lam _ as t -> "(" ^ string_of_term_no_pars_lam lev l t ^ ")"
   | `Match(t,(v,ar),bs_lift,bs,args) ->
-     "["^ string_of_var v ^ (if debug_display_arities then ":"^ string_of_int ar else "") ^",match " ^ string_of_term_no_pars l (t :> nf) ^
-     " with " ^ String.concat " | " (List.map (fun (n,t) -> string_of_int n ^ " => " ^ string_of_term l (lift bs_lift (t :> nf))) !bs) ^ "] " ^
+      (* assert (bs_lift = lev); *)
+     "(["^ varname 0 l v ^ (if debug_display_arities then ":"^ string_of_int ar else "") ^",match " ^ string_of_term_no_pars lev l (t :> nf) ^
+     " with " ^ String.concat " | " (List.map (fun (n,t) -> string_of_int n ^ " => " ^ string_of_term l (t :> nf)) !bs) ^ "] " ^
      String.concat " " (List.map (string_of_term l) (args :> nf list)) ^ ")"
- and string_of_term_no_pars_app l  = function
-  | `I((n,ar), args) -> print_name l n ^ (if debug_display_arities then ":" ^ string_of_int ar else "") ^ " " ^ String.concat " " (List.map (string_of_term_w_pars l) (Listx.to_list args :> nf list))
-  | #nf as t -> string_of_term_w_pars l t
- and string_of_term_no_pars_lam l  = function
-  | `Lam(_,t) -> let name = string_of_var (List.length l) in
-     "λ" ^ name ^ ". " ^ (string_of_term_no_pars_lam (name::l) t)
-  | _ as t -> string_of_term_no_pars l t
- and string_of_term_no_pars l : nf -> string = function
-  | `Lam _ as t -> string_of_term_no_pars_lam l t
-  | #nf as t -> string_of_term_no_pars_app l t
- in string_of_term_no_pars l
+ and string_of_term_no_pars_app lev l  = function
+  | `I((n,ar), args) -> varname lev l n ^ (if debug_display_arities then ":" ^ string_of_int ar else "") ^ " " ^ String.concat " " (List.map (string_of_term_w_pars lev l) (Listx.to_list args :> nf list))
+  | #nf as t -> string_of_term_w_pars lev l t
+ and string_of_term_no_pars_lam lev l  = function
+  | `Lam(_,t) -> "λ" ^ boundvar lev ^ ". " ^ (string_of_term_no_pars_lam (lev+1) l t)
+  | _ as t -> string_of_term_no_pars lev l t
+ and string_of_term_no_pars lev l = function
+  | `Lam _ as t -> string_of_term_no_pars_lam lev l t
+  | #nf as t -> string_of_term_no_pars_app lev l t
+ in string_of_term_no_pars 0
 ;;
 
 let print ?(l=[]) = string_of_term l;;
@@ -162,6 +178,7 @@ let cast_to_i_num_var =
     assert false (* algorithm failed *)
 
 let rec set_arity arity = function
+(* FIXME because onlt variables should be in branches of matches, one day *)
 | `Var(n,_) -> `Var(n,arity)
 | `N _ as t -> t
 | `Lam(false, t) -> `Lam(false, set_arity arity t)
@@ -222,12 +239,16 @@ and subst truelam delift_by_one what (with_what : nf) (where : nf) =
    | `N _ as x -> x
    | `Match(t,v,bs_lift,bs,args) ->
        let bs_lift = bs_lift + if delift_by_one then -1 else 0 in
+       (* Warning! It now applies again the substitution in branches of matches.
+          But careful, it does it many times, for every occurrence of
+          the match. This is okay because what does not occur in with_what. *)
        let l' = l - bs_lift  in
-       let with_what' = lift l' with_what in
+       let with_what' = lift l' (with_what :> nf) in
        (* The following line should be the identity when delift_by_one = true because we
           are assuming the ts to not contain lambda-bound variables. *)
        bs := List.map (fun (n,t) -> n,subst truelam false what with_what' t) !bs ;
-       mk_match (cast_to_i_num_var (aux_i_num_var l t)) v bs_lift bs (List.map (aux l) args)
+       let body = cast_to_i_num_var (aux_i_num_var l t) in
+       mk_match body v bs_lift bs (List.map (aux l) (args :> nf list))
  and aux l(*lift*) =
 (*function iii -> let res = match iii with*)
   function
@@ -239,20 +260,6 @@ prerr_endline ("subst l:" ^ string_of_int l ^ " delift_by_one:" ^ string_of_bool
   aux 0 where
 ;;
 
-(************ Parsing ************************************)
-
-let parse' strs =
-  let fix_arity = function
-  | `I((n,_),args) -> `I((n,1+Listx.length args),args)
-  | _ -> assert false in
-  let rec aux = function
-  | Parser.Lam t -> `Lam (true, aux t)
-  | Parser.App (t1, t2) -> fix_arity (mk_app (aux t1) (aux t2))
-  | Parser.Var v -> `Var(v,1) in
-  let (tms, free) = Parser.parse_many strs in
-  List.map aux tms, free
-;;
-
 (************** Algorithm(s) ************************)
 
 let eta_compare x y =