-type var = (* unique name *) int * (int * term) option * (*level*) int\r
-and term =\r
- | Tvar of var\r
- | Tapp of term * term\r
- | Tlam of int * term\r
-;;\r
-\r
-let zero = Tvar(1010, None, 0);;\r
-let dummy = Tvar(333, None, 0);;\r
-\r
-(* mk_app & subst implementano la beta *)\r
-let rec mk_app t1 t2 = match t1 with\r
- | Tlam(v, t1') -> subst v t2 t1'\r
- | _ -> Tapp(t1, t2)\r
-and subst v tv =\r
- let rec aux = function\r
- | Tapp(t1, t2) -> mk_app (aux t1) (aux t2)\r
- | Tvar(v', _, _) as t -> if v = v' then tv else t\r
- | Tlam(v', t') as t -> if v = v' then t else Tlam(v', aux t')\r
- in aux\r
-;;\r
-\r
-(* PARSING AND PRINTING *)\r
-\r
-let parse =\r
- let rec minus1 = function\r
- | Tvar(n, None, x) -> Tvar(n-1, None, x)\r
- | Tvar _ -> assert false\r
- | Tapp(t1, t2) -> Tapp(minus1 t1, minus1 t2)\r
- | Tlam(n, t) -> Tlam(n-1, minus1 t)\r
- (* in let open Parser *)\r
- in let rec myterm_of_term = function\r
- | Parser.Var n -> Tvar(n, None, 0)\r
- | Parser.App(t1, t2) -> (*Tapp(myterm_of_term t1, myterm_of_term t2) WARNING! BETA DOWN HERE! *)\r
- mk_app (myterm_of_term t1) (myterm_of_term t2)\r
- | Parser.Lam(t) -> minus1 (Tlam(0, myterm_of_term t))\r
- in fun strs -> (\r
- let (tms, free) = Parser.parse_many strs\r
- in List.map myterm_of_term tms\r
- )\r
-;;\r
-\r
-(* PRETTY PRINTING *)\r
-open Console;;\r
-\r
-let fancy_of_term t =\r
-let rec string_of_term =\r
- let free = ["a"; "b"; "c"; "d"; "e"; "f"; "g"] in\r
- let bound = ["x"; "y"; "z"; "w"; "q"; "x1"; "x2"] in\r
- let string_of_int' n = if n >= 0 then List.nth free (n) else List.nth bound (-n-1) in\r
- let rec string_of_var t =\r
- if Tvar t = dummy then "_" else if Tvar t = zero then "ZZ" else match t with\r
- | (n, None, _) -> (string_of_int' n)\r
- (* | (_, Some(n,t), _) -> "?" ^ string_of_int n *)\r
- | (_, Some(n,t), _) -> "{" ^ (string_of_term_no_pars t) ^ "|" ^ (string_of_int n) ^ "}"\r
- and string_of_term_w_pars = function\r
- | Tvar v -> string_of_var v\r
- | Tapp(t1, t2) -> "(" ^ (string_of_term_no_pars_app t1) ^ " " ^ (string_of_term_w_pars t2) ^ ")"\r
- | Tlam(_,_) as t -> "(" ^ (string_of_term_no_pars_lam t) ^ ")"\r
- and string_of_term_no_pars_app = function\r
- | Tapp(t1, t2) -> (string_of_term_no_pars_app t1) ^ " " ^ (string_of_term_w_pars t2)\r
- | _ as t -> string_of_term_w_pars t\r
- and string_of_term_no_pars_lam = function\r
- | Tlam(v, t) -> "λ" ^ (string_of_int' v) ^ ". " ^ (string_of_term_no_pars_lam t)\r
- | _ as t -> string_of_term_no_pars t\r
- and string_of_term_no_pars = function\r
- | Tlam(_, _) as t -> string_of_term_no_pars_lam t\r
- | _ as t -> string_of_term_no_pars_app t\r
- in string_of_term_no_pars\r
-in let rec html_of_term =\r
- let free = ["a"; "b"; "c"; "d"; "e"; "f"; "g"; "h"; "i"; "j"] in\r
- let bound = ["x"; "y"; "z"; "w"; "q"] in\r
- let string_of_int' n = if n >= 0 then List.nth free (n) else List.nth bound (-n-1) in\r
- let rec string_of_var t =\r
- if Tvar t = dummy then "#" else if Tvar t = zero then "Z" else match t with\r
- | (n, None, _) -> (string_of_int' n)\r
- | (_, Some(n,t), _) -> "α<sup>" ^ (string_of_term_no_pars t) ^ "</sup><sub>" ^ (string_of_int n) ^ "</sub>"\r
- and string_of_term_w_pars = function\r
- | Tvar v -> string_of_var v\r
- | Tapp(t1, t2) -> "(" ^ (string_of_term_no_pars_app t1) ^ " " ^ (string_of_term_w_pars t2) ^ ")"\r
- | Tlam(_,_) as t -> "(" ^ (string_of_term_no_pars_lam t) ^ ")"\r
- and string_of_term_no_pars_app = function\r
- | Tapp(t1, t2) -> (string_of_term_no_pars_app t1) ^ " " ^ (string_of_term_w_pars t2)\r
- | _ as t -> string_of_term_w_pars t\r
- and string_of_term_no_pars_lam = function\r
- | Tlam(v, t) -> "λ" ^ (string_of_int' v) ^ ". " ^ (string_of_term_no_pars_lam t)\r
- | _ as t -> string_of_term_no_pars t\r
- and string_of_term_no_pars = function\r
- | Tlam(_, _) as t -> string_of_term_no_pars_lam t\r
- | _ as t -> string_of_term_no_pars_app t\r
- in string_of_term_no_pars\r
-in\r
- string_of_term t / html_of_term t\r
-;;\r
-\r
-let fancy_of_nf t: Console.fancyobj =\r
-let rec print ?(l=[]) =\r
- function\r
- `Var n -> Lambda3.print_name l n\r
- | `N n -> string_of_int n\r
- | `Match(t,bs_lift,bs,args) ->\r
- "([" ^ print ~l (t :> Lambda3.nf) ^\r
- " ? " ^ String.concat " | " (List.map (fun (n,t) -> string_of_int n ^ " => " ^ print ~l (Lambda3.lift bs_lift t)) !bs) ^ "] " ^\r
- String.concat " " (List.map (print ~l) args) ^ ")"\r
- | `I(n,args) -> "(" ^ Lambda3.print_name l n ^ " " ^ String.concat " " (Listx.to_list (Listx.map (print ~l) args)) ^ ")"\r
- | `Lam nf ->\r
- let name = Lambda3.string_of_var (List.length l) in\r
- "" ^ name ^ "." ^ print ~l:(name::l) (nf : Lambda3.nf)\r
-\r
-in let rec print_html ?(l=[]) =\r
- function\r
- `Var n -> Lambda3.print_name l n\r
- | `N n -> string_of_int n\r
- | `Match(t,bs_lift,bs,args) ->\r
- "(<b>match</b> " ^ print_html ~l (t :> Lambda3.nf) ^\r
- " <b>with</b> " ^ String.concat " <b>|</b> " (List.map (fun (n,t) -> string_of_int n ^ " <b>⇒</b> " ^ print_html ~l (Lambda3.lift bs_lift t)) !bs) ^ "..." (* Attenzion non sto stampando gli argomenti applicati! Perche' non ce ne sono mai *)\r
- | `I(n,args) -> "(" ^ Lambda3.print_name l n ^ " " ^ String.concat " " (Listx.to_list (Listx.map (print_html ~l) args)) ^ ")"\r
- | `Lam nf ->\r
- let name = Lambda3.string_of_var (List.length l) in\r
- "λ" ^ name ^ ". " ^ print_html ~l:(name::l) (nf : Lambda3.nf)\r
-in\r
- print t / print_html t\r
-;;\r
-\r
-let print_term t = print_endline (fancy_of_term t :> Console.fancyobj);;\r
-(* *)\r
-\r
-\r
-let varcount = ref 0;;\r
-\r
-let freshvar () = (\r
- varcount := (!varcount + 1);\r
- !varcount\r
-);;\r
-\r
-let rec hd =\r
- function\r
- | Tvar x -> x\r
- | Tapp(t1,t2) -> hd t1\r
- | Tlam _ -> assert false\r
-;;\r
-\r
-let alive (_, _, n) = n;;\r
-let rec setalive c = function\r
- | Tvar(a,b,_) as v -> if v <> zero && v <> dummy then Tvar(a,b,c) else v\r
- | Tapp(a,b) -> Tapp(setalive c a, setalive c b)\r
- | Tlam(n, t) -> Tlam(n, setalive c t)\r
-;;\r
-\r
-let mk_vars t lev =\r
- let rec aux n =\r
- if n = 0\r
- then []\r
- else Tvar(0, Some(n, t), lev) :: (aux (n-1))\r
- in aux\r
-;;\r
-\r
-let mk_apps t ts = List.fold_right (fun x y -> mk_app y x) (List.rev ts) t;; (* which FOLD? FIXME *)\r
-\r
-\r
-let compute_special_k tms =\r
- let rec aux k t = match t with\r
- | Tvar _ -> 0\r
- | Tapp(t1,t2) -> Pervasives.max (aux 0 t1) (aux 0 t2)\r
- | Tlam(v,t) -> Pervasives.max (k+1) (aux (k + 1) t)\r
- in List.fold_left (fun b a -> Pervasives.max (aux 0 a) b) 0 tms\r
-;;\r
-\r
-let compute_special_h tms =\r
- let rec eat_lam = function\r
- | Tlam(_,t) -> eat_lam t\r
- | _ as t -> t\r
- in\r
- let rec aux t = match t with\r
- | Tvar _ -> 0\r
- | Tapp(t1,t2) -> Pervasives.max (aux t1) (aux t2)\r
- | Tlam(v,t) -> 1 + (aux (eat_lam t))\r
- in 1 + List.fold_left (fun b a -> Pervasives.max (aux a) b) 0 tms\r
-;;\r
-\r
-(* funzione di traduzione brutta & cattiva *)\r
-let translate k =\r
- let rec aux = function\r
- | Tlam _ -> assert false\r
- | Tvar _ as v -> v\r
- | Tapp(t1, t2) ->\r
- let v = hd t1 in\r
- let a = alive v in\r
- let t1' = aux t1 in\r
- let t2' = if a = 0\r
- then t2\r
- else mk_apps t2 ((List.rev (mk_vars t1' (a-1) k)) @ [zero])\r
- in Tapp(t1', aux t2')\r
- in aux\r
-;;\r
-\r
-(* sostituisce gli argomenti dummy (delle variabili morte) con 'dummy' *)\r
-let rec dummize = function\r
- | Tlam _ -> assert false\r
- | Tvar (a,Some(b,t), c) -> Tvar(a, Some (b, dummize t), c)\r
- | Tvar _ as v -> v\r
- | Tapp(t1, t2) ->\r
- if alive (hd t1) = 0\r
- then Tapp(dummize t1, dummy)\r
- else Tapp(dummize t1, dummize t2)\r
-;;\r
-\r
-(* lista di sottotermini applicativi *)\r
-let rec subterms = function\r
- | Tlam _ -> assert false\r
- | Tvar _ as v -> [v]\r
- | Tapp(t1, t2) -> Tapp(t1, t2) :: ((subterms t1) @ (subterms t2))\r
-;;\r
-\r
-(* filtra dai sottotermini le variabili *)\r
-let rec vars subs = List.filter (function Tvar _ -> true | _ -> false) subs;;\r
-\r
-\r
-let rec stupid_uniq = function\r
- | [] -> []\r
- | x::xs -> if List.mem x xs then (stupid_uniq xs) else x::(stupid_uniq xs)\r
-;;\r
-let stupid_compare a b =\r
- let rec size = function\r
- | Tvar(_,None,_) -> 0\r
- | Tvar(_,Some(_,t),_) -> 1 + size t\r
- | Tapp(t1,t2) -> 1 + size t1 + size t2\r
- | Tlam _ -> assert false\r
- in compare (size a) (size b)\r
-;;\r
-let stupid_sort_uniq l = stupid_uniq (List.sort stupid_compare l);;\r
-\r
-(* crea i match ricorsivamente.\r
- - k e' lo special-K\r
- - subs e' l'insieme dei sottotermini\r
- TODO: riscrivere la funzione per evitare/ottimizzare la ricorsione\r
- *)\r
-let crea_match k subs (acc : (term * Lambda3.nf) list) : term -> Lambda3.nf =\r
- let req t = try List.assoc t acc with Not_found -> `Var 9999 in\r
- let aux t1 = (\r
- if t1 = dummy then `Var 99999 else\r
- (* let _ = print_term t1 in *)\r
- let cont = List.filter (fun t2 -> List.mem (Tapp(t1,t2)) subs) subs\r
- in if cont = [] then\r
- try `N (Lambda3.index_of t1 subs) with Not_found -> `Var 999 (* variabile dummy qui *) else\r
- let a = alive (hd t1) in\r
- if a = 0 then `Lam (req (Tapp(t1, dummy)))\r
- else (\r
- let vars = (List.rev (mk_vars t1 (a-1) k)) @ [zero]\r
- (* in let _ = print_endline (String.concat " " (List.map string_of_term vars))\r
- in let _ = print_term (mk_apps dummy vars) *)\r
- in let vars = List.map req vars\r
- in let vars = List.map (Lambda3.lift 1) vars (* forse lift non necessario *)\r
- in let vars = Listx.from_list vars\r
- in let body = `I(0, vars)\r
- in let branches = List.map (fun t2 -> (Lambda3.index_of t2 subs, req (Tapp(t1, t2)))) cont\r
- in let bs = ref(branches)\r
- in let lift = 1\r
- in let args = []\r
- in `Lam (`Match(body, lift, bs, args))\r
- )\r
- ) in aux\r
-;;\r
-\r
-let mk_zeros k =\r
- let rec aux n prev =\r
- if n = 0 then [zero]\r
- else let prev = aux (n-1) prev in let x = mk_app (List.hd prev) dummy in x :: prev\r
- in aux (k+1) []\r
-;;\r
-\r
-let is_scott_n t n =\r
- let open Lambda3 in let open Pure in\r
- let rec aux n = function\r
- | L (L (A (V 1, L (V 0)))) -> n = 0\r
- | L (L (A (V 0, t))) -> aux (n-1) t\r
- | _ -> assert false\r
- in aux n t\r
-;;\r
-\r
-(* do the magic *)\r
-let magic strings k h = (\r
- let tms = parse strings\r
- in let tms = List.map (fun x -> Tapp(x, zero)) tms\r
- in let tms' = List.map (setalive h) tms\r
- in let tms' = List.map (translate k) tms'\r
- in let tms' = List.map dummize tms'\r
- in let progress s = print_bullet (fancy_of_string s)\r
- in let _ = progress "traduzione completata"\r
- (* in let _ = List.map print_term tms' *)\r
- in let _ = progress "ordino i sottotermini"\r
- in let subs = List.concat (List.map subterms tms')\r
- in let subs = stupid_sort_uniq subs\r
- (* metti gli zeri in testa, perche' vanno calcolati per primi *)\r
- in let zeros = mk_zeros k\r
- in let subs = (List.filter (fun t -> not (List.mem t zeros)) subs) @ (List.rev zeros)\r
- in let _ = progress ("sottotermini generati: " ^ string_of_int (List.length subs))\r
- in let vars = vars subs\r
- (* in let _ = List.iter print_term subs *)\r
- (* in let _ = 0/0 *)\r
- in let fv = List.filter (function Tvar(_, None, _) as v -> v <> dummy | _ -> false) vars\r
- (* in let _ = print_string ("> free vars: " ^ String.concat ", " (List.map (string_of_term) fv)) *)\r
- in let _ = progress "sto creando i match"\r
- (* in let sigma = List.map (fun x -> x, crea_match k subs x) fv *)\r
- in let f t acc = let res = crea_match k subs acc t in (t,res)::acc\r
- in let acc = List.fold_right f subs []\r
- in let sigma = List.filter (fun (t,res) -> List.mem t fv) acc\r
- in let _ = progress "match creati"\r
- in let _ = List.iter (fun (x,y) -> print_endline (fancy_of_term x ^^ (" : " / " ↦ ") ^^ fancy_of_nf y)) sigma\r
-\r
- in let _ = progress "controllo di purezza";\r
- in let open Lambda3\r
- in let ps, _ = Lambda3.parse' strings\r
- in let ps = List.map (fun x -> Lambda3.mk_app x (`Var 1010)) ps\r
- in let ps = List.map (fun t -> ToScott.t_of_nf (t :> nf)) ps\r
- in let sigma = List.map (\r
- function (Tvar(n,_,_), inst) -> n, ToScott.t_of_nf inst | _ -> assert false\r
- ) sigma\r
- in let ps =\r
- List.fold_left (fun ps (x,inst) -> List.map (Pure.subst false x inst) ps) ps sigma\r
- in let _ = List.iteri (fun i n ->\r
- (* print_string_endline ((string_of_int i) ^ ":: " ^ (Pure.print (Pure.whd n))); *)\r
- (* assert (Pure.whd n = Scott.mk_n (Lambda3.index_of (List.nth tms' i) subs))) ps *)\r
- assert (is_scott_n (Pure.whd n) (Lambda3.index_of (List.nth tms' i) subs))) ps\r
- in let _ = progress "fatto." in ()\r
-);;\r
-\r
-let do_everything tms =\r
-let tms' = parse tms in\r
-let _ = List.iter print_term tms' in\r
-let k = compute_special_k tms' in\r
-let h = compute_special_h tms' in\r
-(* let _ = print_string_endline (string_of_int h) in *)\r
-magic tms k h\r
-;;\r
-\r
-let _ =\r
- let tms = ["a a"; "a b"; "b a"; "b (x. y.x y a)"] in\r
- (* 1 2 *)\r
- (* let tms = ["x c" ; "b (x c d e)"; "b"] in *)\r
- (* 0 1 *)\r
- (* let tms = ["x x x"] in *)\r
- let tms' = parse tms in\r
- let _ = List.iter print_term tms' in\r
- let k = compute_special_k tms' in\r
- let h = compute_special_h tms' in\r
- (* let _ = print_string_endline (string_of_int h) in *)\r
- magic tms k h\r
-;;\r
-\r
-(* type var' = (* unique name *) int * (int * term') option * (*dead*) bool option\r
-and term' =\r
- | Tvar' of var'\r
- | Tapp' of term' * term' * (* active *) bool\r
- | Tlam' of int * term'\r
-;;\r
-\r
-let rec iter mustapply =\r
- let aux = function\r
- | Tvar'(n, Some(m,t), b) -> Tvar(n, Some(m, aux t), b)\r
- | Tvar' _ as v -> v\r
- | Tapp'(t1, t2, b) -> if b &&\r
- in aux\r
-;; *)\r