Fix: nested `Lambda(false,_) were not handled correctly

[fireball-separation.git] / ocaml / num.ml

diff --git a/ocaml/num.ml b/ocaml/num.ml
index 3c84f4f6236f937ed4eec92efbf3f5eabd261ef4..eb37e4ca41d0c1b2b6f27f6ddf24edadacaba842 100644 (file)
--- a/ocaml/num.ml
+++ b/ocaml/num.ml
@@ -70,12 +70,12 @@ let rec make_lams t =
  | n when n > 0 -> `Lam (false, lift 1 (make_lams t (n-1)))
  | _ -> assert false
 
-let free_vars =
+let free_vars' =
  let rec aux n = function
     `N _ -> []
-  | `Var(x,_) -> if x < n then [] else [x-n]
-  | `I((x,_),args) ->
-      (if x < n then [] else [x-n]) @
+  | `Var(x,ar) -> if x < n then [] else [(x-n,ar)]
+  | `I((x,ar),args) ->
+      (if x < n then [] else [(x-n,ar)]) @
       List.concat (List.map (aux n) (Listx.to_list args))
   | `Lam(_,t) -> aux (n+1) t
   | `Match(t,_,liftno,bs,args) ->
@@ -84,6 +84,7 @@ let free_vars =
       List.concat (List.map (aux n) args)
   in aux 0
 ;;
+let free_vars = (List.map fst) ++ free_vars';;
 
 module ToScott =
 struct
@@ -114,8 +115,8 @@ let rec string_of_term l =
   | `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 ^ ")"
-  | `Match(t,_,bs_lift,bs,args) ->
-     "(match " ^ string_of_term_no_pars l (t :> nf) ^
+  | `Match(t,(v,ar),bs_lift,bs,args) ->
+     "[match("^ string_of_var v ^":"^ string_of_int ar ^") " ^ 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)) !bs) ^ "] " ^
      String.concat " " (List.map (string_of_term l) args) ^ ")"
  and string_of_term_no_pars_app l = function
@@ -157,12 +158,14 @@ let cast_to_i_num_var =
     prerr_endline (print (t :> nf));
     assert false (* algorithm failed *)
 
-let set_arity arity = function
+let rec set_arity arity = function
 | `Var(n,_) -> `Var(n,arity)
-| `Lam(false, `N _)
-| `Lam(false, `Lam _) as t -> t
-| `Lam(false, `Match(t,(n,ar),bs_lift,bs,args)) -> `Lam(false, `Match(t,(n,arity),bs_lift,bs,args))
-| _ -> assert false
+| `N _ as t -> t
+| `Lam(false, t) -> `Lam(false, set_arity arity t)
+| `Match(t,(n,_),bs_lift,bs,args) -> `Match(t,(n,arity),bs_lift,bs,args)
+| `I _ | `Lam _ -> assert false
+
+let minus1 n = if n = min_int then n else n - 1;;
 
 let rec mk_app (h : nf) (arg : nf) =
 (*let res =*)
@@ -187,7 +190,7 @@ and mk_match t (n,ar) bs_lift bs args =
     `N m ->
       (try
         let h = List.assoc m !bs in
-        let h = set_arity (ar-1) h in
+        let h = set_arity (minus1 ar) h in
         let h = lift bs_lift h in
         mk_appl h args
        with Not_found ->
@@ -195,10 +198,11 @@ and mk_match t (n,ar) bs_lift bs args =
   | `I _ | `Var _ | `Match _ -> `Match(t,(n,ar),bs_lift,bs,args)
 
 and subst truelam delift_by_one what (with_what : nf) (where : nf) =
- let aux_propagate_arity ar = function
- | `Lam(false,`Match(`I(v,args),(x,_),liftno,bs,args')) when not delift_by_one ->
-    `Lam(false,`Match(`I(v,args),(x,ar),liftno,bs,args'))
- | `Var(i,_) -> `Var(i,ar)
+ let rec aux_propagate_arity ar = function
+ | `Lam(false, t) when not delift_by_one -> `Lam(false, aux_propagate_arity ar t)
+ | `Match(`I(v,args),(x,_),liftno,bs,args') when not delift_by_one ->
+    `Match(`I(v,args),(x,ar),liftno,bs,args')
+ | `Var(i,oldar) -> `Var(i, if truelam then (assert (oldar = min_int); ar) else oldar)
  | _ as t -> t in
  let rec aux_i_num_var l =
   function
@@ -236,12 +240,12 @@ prerr_endline ("subst l:" ^ string_of_int l ^ " delift_by_one:" ^ string_of_bool
 
 let parse' strs =
   let fix_arity = function
-  | `I((n,_),args) -> `I((n,Listx.length args),args)
+  | `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,0) in
+  | Parser.Var v -> `Var(v,1) in
   let (tms, free) = Parser.parse_many strs in
   List.map aux tms, free
 ;;
@@ -305,15 +309,20 @@ let eta_subterm (#nf as x) (#nf as y) = eta_subterm x y;;
 
 
 let max_arity_tms n =
- let aux_var l (m,a) = if n + l = m then a else -1 in
+ let max a b = match a, b with
+  | None, None -> None
+  | None, Some x
+  | Some x, None -> Some x
+  | Some x, Some y -> Some (Pervasives.max x y) in
+ let aux_var l (m,a) = if n + l = m then Some a else None in
  let rec aux l = function
   | `Var v -> aux_var l v
   | `I(v,tms) -> max (aux_var l v) (aux_tms l (Listx.to_list tms))
   | `Lam(_,t) -> aux (l+1) t
   | `Match(u,_,_,bs,args) -> max (max (aux l (u :> nf)) (aux_tms l args)) (aux_tms l (List.map snd !bs))
-  | `N _ -> -1
+  | `N _ -> None
  and aux_tms l =
-  List.fold_left (fun acc t -> Pervasives.max acc (aux l t)) ~-1 in
+  List.fold_left (fun acc t -> Pervasives.max acc (aux l t)) None in
  fun tms -> aux_tms 0 (tms :> nf list)
 ;;
 
@@ -333,7 +342,7 @@ let compute_arities m =
    then []
    else
     let tms = Util.filter_map (function `Lam(_,t) -> Some t | _ -> None ) tms in
-    let arity = max 0 (max_arity_tms (m-n) tms) in (* FIXME: 0 or -1 ??? *)
+    let arity = match max_arity_tms (m-n) tms with None -> -666 | Some x -> x in
      arity :: (aux (n-1) tms)
  in fun tms -> List.rev (aux m tms)
 ;;