open Util.Vars
open Pure
+(* debug options *)
+let debug_display_arities = false;;
+
(************ Syntax ************************************)
(* Normal forms*)
| 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) ->
List.concat (List.map (aux n) args)
in aux 0
;;
+let free_vars = (List.map fst) ++ free_vars';;
module ToScott =
struct
(************ 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 l =
+ let rec string_of_term_w_pars l = function
+ | `Var(n,ar) -> List.nth 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 ^ ")"
- | `Match(t,_,bs_lift,bs,args) ->
- "(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)) !bs) ^ "] " ^
- String.concat " " (List.map (string_of_term l) args) ^ ")"
- and string_of_term_no_pars_app l = function
- | `I((n,ar), args) -> print_name l n ^ ":" ^ string_of_int ar ^ " " ^ String.concat " " (List.map (string_of_term_w_pars l) (Listx.to_list args))
+ | `Match(t,(v,ar),bs_lift,bs,args) ->
+ "["^ List.nth l 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) ^ "] " ^
+ String.concat " " (List.map (string_of_term l) (args :> nf list)) ^ ")"
+ and string_of_term_no_pars_app l = function
+ | `I((n,ar), args) -> List.nth 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)
+ | `Lam(_,t) -> let name = "x" ^ string_of_int (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
prerr_endline (print (t :> nf));
assert false (* algorithm failed *)
-let set_arity arity = function
+let rec set_arity arity = function
+(* FIXME because onlt variables should be in branches of matches, one day *)
| `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 =*)
`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 ->
| `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
aux 0 where
;;
-(************ Parsing ************************************)
-
-let parse' strs =
- let fix_arity = function
- | `I((n,_),args) -> `I((n,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
- let (tms, free) = Parser.parse_many strs in
- List.map aux tms, free
-;;
-
(************** Algorithm(s) ************************)
let eta_compare x y =
| `Match(u,ar,liftno,bs,args) ->
eta_subterm sub (u :> nf)
|| List.exists (fun (_, t) -> eta_subterm sub (lift liftno t)) !bs
- || List.exists (eta_subterm sub) args
- | `I(v, args) -> List.exists (eta_subterm sub) (Listx.to_list args) || (match sub with
- | `Var v' -> v = v'
- | `I(v', args') -> v = v'
+ || List.exists (eta_subterm sub) (args :> nf list)
+ | `I((v,_), args) -> List.exists (eta_subterm sub) ((Listx.to_list args) :> nf list) || (match sub with
+ | `Var(v',_) -> v = v'
+ | `I((v',_), args') -> v = v'
&& Listx.length args' < Listx.length args
&& List.for_all (fun (x,y) -> eta_eq x y) (List.combine (Util.take (Listx.length args') (Listx.to_list args)) (Listx.to_list args'))
| _ -> false
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 -> max acc (aux l t)) None in
fun tms -> aux_tms 0 (tms :> nf list)
;;
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)
;;