1 (***********************************************************************)
5 (* Kim Nguyen, LRI UMR8623 *)
6 (* Université Paris-Sud & CNRS *)
8 (* Copyright 2010-2013 Université Paris-Sud and Centre National de la *)
9 (* Recherche Scientifique. All rights reserved. This file is *)
10 (* distributed under the terms of the GNU Lesser General Public *)
11 (* License, with the special exception on linking described in file *)
14 (***********************************************************************)
17 Time-stamp: <Last modified on 2013-04-24 18:10:13 CEST by Kim Nguyen>
23 type predicate = | First_child
30 | Is of (Tree.NodeKind.t)
34 let is_move p = match p with
35 | First_child | Next_sibling
36 | Parent | Previous_sibling | Stay -> true
40 type atom = predicate * bool * State.t
42 module Atom : (Formula.ATOM with type data = atom) =
48 let equal n1 n2 = n1 = n2
49 let hash n = Hashtbl.hash n
52 include Hcons.Make(Node)
55 let p, b, q = a.node in
56 if not b then fprintf ppf "%s" Pretty.lnot;
58 | First_child -> fprintf ppf "FC(%a)" State.print q
59 | Next_sibling -> fprintf ppf "NS(%a)" State.print q
60 | Parent -> fprintf ppf "FC%s(%a)" Pretty.inverse State.print q
61 | Previous_sibling -> fprintf ppf "NS%s(%a)" Pretty.inverse State.print q
62 | Stay -> fprintf ppf "%s(%a)" Pretty.epsilon State.print q
63 | Is_first_child -> fprintf ppf "FC%s?" Pretty.inverse
64 | Is_next_sibling -> fprintf ppf "NS%s?" Pretty.inverse
65 | Is k -> fprintf ppf "is-%a?" Tree.NodeKind.print k
66 | Has_first_child -> fprintf ppf "FC?"
67 | Has_next_sibling -> fprintf ppf "NS?"
70 let p, b, q = a.node in
78 include Formula.Make(Atom)
80 let mk_atom a b c = atom_ (Atom.make (a,b,c))
81 let mk_kind k = mk_atom (Is k) true State.dummy
83 (mk_atom Has_first_child true State.dummy)
85 let has_next_sibling =
86 (mk_atom Has_next_sibling true State.dummy)
89 (mk_atom Is_first_child true State.dummy)
92 (mk_atom Is_next_sibling true State.dummy)
95 (mk_atom (Is Attribute) true State.dummy)
98 (mk_atom (Is Element) true State.dummy)
100 let is_processing_instruction =
101 (mk_atom (Is ProcessingInstruction) true State.dummy)
104 (mk_atom (Is Comment) true State.dummy)
108 (mk_atom First_child true q)
113 (mk_atom Next_sibling true q)
118 (mk_atom Parent true q)
121 let previous_sibling q =
123 (mk_atom Previous_sibling true q)
127 (mk_atom Stay true q)
132 | Formula.Atom a -> let _, _, q = Atom.node a in
133 if q != State.dummy then StateSet.add q acc else acc
140 module Transition = Hcons.Make (struct
141 type t = State.t * QNameSet.t * SFormula.t
142 let equal (a, b, c) (d, e, f) =
143 a == d && b == e && c == f
145 HASHINT4 (PRIME1, a, ((QNameSet.uid b) :> int), ((SFormula.uid c) :> int))
149 module TransList : sig
150 include Hlist.S with type elt = Transition.t
151 val print : Format.formatter -> ?sep:string -> t -> unit
154 include Hlist.Make(Transition)
155 let print ppf ?(sep="\n") l =
157 let q, lab, f = Transition.node t in
158 fprintf ppf "%a, %a -> %a%s" State.print q QNameSet.print lab SFormula.print f sep) l
163 type node_summary = int
164 let dummy_summary = -1
174 let has_right (s : node_summary) : bool =
176 let has_left (s : node_summary) : bool =
177 Obj.magic ((s lsr 1) land 1)
179 let is_right (s : node_summary) : bool =
180 Obj.magic ((s lsr 2) land 1)
182 let is_left (s : node_summary) : bool =
183 Obj.magic ((s lsr 3) land 1)
185 let kind (s : node_summary ) : Tree.NodeKind.t =
188 let node_summary is_left is_right has_left has_right kind =
189 ((Obj.magic kind) lsl 4) lor
190 ((Obj.magic is_left) lsl 3) lor
191 ((Obj.magic is_right) lsl 2) lor
192 ((Obj.magic has_left) lsl 1) lor
193 (Obj.magic has_right)
201 summary : node_summary;
202 (** optimization infos,
203 not taken into account during hashconsing *)
205 mutable unstable_subtree : bool;
208 module Config = Hcons.Make(struct
213 c.unsat == d.unsat &&
215 c.summary == d.summary
218 HASHINT4((c.sat.StateSet.id :> int),
219 (c.unsat.StateSet.id :> int),
220 (c.todo.TransList.id :> int),
227 mutable states : StateSet.t;
228 mutable selection_states: StateSet.t;
229 transitions: (State.t, (QNameSet.t*SFormula.t) list) Hashtbl.t;
230 mutable cache2 : TransList.t Cache.N2.t;
231 mutable cache4 : Config.t Cache.N4.t;
234 let next = Uid.make_maker ()
236 let dummy2 = TransList.cons
237 (Transition.make (State.dummy,QNameSet.empty, SFormula.false_))
242 let dummy_config = Config.make { sat = StateSet.empty;
243 unsat = StateSet.empty;
244 todo = TransList.nil;
245 summary = dummy_summary;
247 unstable_subtree = true;
252 let auto = { id = next ();
254 selection_states = ss;
255 transitions = Hashtbl.create 17;
256 cache2 = Cache.N2.create dummy2;
257 cache4 = Cache.N4.create dummy_config;
263 Cache.N2.iteri (fun _ _ _ b -> if b then incr n2) auto.cache2;
264 Cache.N4.iteri (fun _ _ _ _ _ b -> if b then incr n4) auto.cache4;
265 Format.eprintf "STATS: automaton %i, cache2: %i entries, cache6: %i entries\n%!"
266 (auto.id :> int) !n2 !n4;
267 let c2l, c2u = Cache.N2.stats auto.cache2 in
268 let c4l, c4u = Cache.N4.stats auto.cache4 in
269 Format.eprintf "STATS: cache2: length: %i, used: %i, occupation: %f\n%!" c2l c2u (float c2u /. float c2l);
270 Format.eprintf "STATS: cache4: length: %i, used: %i, occupation: %f\n%!" c4l c4u (float c4u /. float c4l)
276 a.cache2 <- Cache.N2.create (Cache.N2.dummy a.cache2);
277 a.cache4 <- Cache.N4.create (Cache.N4.dummy a.cache4)
280 let get_trans_aux a tag states =
281 StateSet.fold (fun q acc0 ->
283 let trs = Hashtbl.find a.transitions q in
284 List.fold_left (fun acc1 (labs, phi) ->
285 if QNameSet.mem tag labs then TransList.cons (Transition.make (q, labs, phi)) acc1 else acc1) acc0 trs
286 with Not_found -> acc0
287 ) states TransList.nil
290 let get_trans a tag states =
292 Cache.N2.find a.cache2
293 (tag.QName.id :> int) (states.StateSet.id :> int)
295 if trs == dummy2 then
296 let trs = get_trans_aux a tag states in
299 (tag.QName.id :> int)
300 (states.StateSet.id :> int) trs; trs)
305 let eval_form phi fcs nss ps ss is_left is_right has_left has_right kind =
307 begin match SFormula.expr phi with
308 Formula.True | Formula.False -> phi
310 let p, b, q = Atom.node a in begin
313 if b == StateSet.mem q fcs then SFormula.true_ else phi
315 if b == StateSet.mem q nss then SFormula.true_ else phi
316 | Parent | Previous_sibling ->
317 if b == StateSet.mem q ps then SFormula.true_ else phi
319 if b == StateSet.mem q ss then SFormula.true_ else phi
320 | Is_first_child -> SFormula.of_bool (b == is_left)
321 | Is_next_sibling -> SFormula.of_bool (b == is_right)
322 | Is k -> SFormula.of_bool (b == (k == kind))
323 | Has_first_child -> SFormula.of_bool (b == has_left)
324 | Has_next_sibling -> SFormula.of_bool (b == has_right)
326 | Formula.And(phi1, phi2) -> SFormula.and_ (loop phi1) (loop phi2)
327 | Formula.Or (phi1, phi2) -> SFormula.or_ (loop phi1) (loop phi2)
332 let int_of_conf is_left is_right has_left has_right kind =
333 ((Obj.magic kind) lsl 4) lor
334 ((Obj.magic is_left) lsl 3) lor
335 ((Obj.magic is_right) lsl 2) lor
336 ((Obj.magic has_left) lsl 1) lor
337 (Obj.magic has_right)
339 let eval_trans auto ltrs fcs nss ps ss is_left is_right has_left has_right kind =
340 let n = int_of_conf is_left is_right has_left has_right kind
341 and k = (fcs.StateSet.id :> int)
342 and l = (nss.StateSet.id :> int)
343 and m = (ps.StateSet.id :> int) in
344 let rec loop ltrs ss =
345 let i = (ltrs.TransList.id :> int)
346 and j = (ss.StateSet.id :> int) in
347 let (new_ltrs, new_ss) as res =
348 let res = Cache.N6.find auto.cache6 i j k l m n in
349 if res == dummy6 then
351 TransList.fold (fun trs (acct, accs) ->
352 let q, lab, phi = Transition.node trs in
353 if StateSet.mem q accs then (acct, accs) else
357 is_left is_right has_left has_right kind
359 if SFormula.is_true new_phi then
360 (acct, StateSet.add q accs)
361 else if SFormula.is_false new_phi then
364 let new_tr = Transition.make (q, lab, new_phi) in
365 (TransList.cons new_tr acct, accs)
366 ) ltrs (TransList.nil, ss)
368 Cache.N6.add auto.cache6 i j k l m n res; res
372 if new_ss == ss then res else
379 let simplify_atom atom pos q { Config.node=config; _ } =
380 if (pos && StateSet.mem q config.sat)
381 || ((not pos) && StateSet.mem q config.unsat) then SFormula.true_
382 else if (pos && StateSet.mem q config.unsat)
383 || ((not pos) && StateSet.mem q config.sat) then SFormula.false_
386 let eval_form phi fcs nss ps ss summary =
388 begin match SFormula.expr phi with
389 Formula.True | Formula.False -> phi
391 let p, b, q = Atom.node a in begin
393 | First_child -> simplify_atom phi b q fcs
394 | Next_sibling -> simplify_atom phi b q nss
395 | Parent | Previous_sibling -> simplify_atom phi b q ps
396 | Stay -> simplify_atom phi b q ss
397 | Is_first_child -> SFormula.of_bool (b == (is_left summary))
398 | Is_next_sibling -> SFormula.of_bool (b == (is_right summary))
399 | Is k -> SFormula.of_bool (b == (k == (kind summary)))
400 | Has_first_child -> SFormula.of_bool (b == (has_left summary))
401 | Has_next_sibling -> SFormula.of_bool (b == (has_right summary))
403 | Formula.And(phi1, phi2) -> SFormula.and_ (loop phi1) (loop phi2)
404 | Formula.Or (phi1, phi2) -> SFormula.or_ (loop phi1) (loop phi2)
411 let eval_trans auto fcs nss ps ss =
412 let fcsid = (fcs.Config.id :> int) in
413 let nssid = (nss.Config.id :> int) in
414 let psid = (ps.Config.id :> int) in
415 let rec loop old_config =
416 let oid = (old_config.Config.id :> int) in
418 let res = Cache.N4.find auto.cache4 oid fcsid nssid psid in
419 if res != dummy_config then res
424 summary = old_summary } = old_config.Config.node
426 let sat, unsat, removed, kept, todo =
429 let q, lab, phi = Transition.node trs in
430 let a_sat, a_unsat, a_rem, a_kept, a_todo = acc in
431 if StateSet.mem q a_sat || StateSet.mem q a_unsat then acc else
433 eval_form phi fcs nss ps old_config old_summary
435 if SFormula.is_true new_phi then
436 StateSet.add q a_sat, a_unsat, StateSet.add q a_rem, a_kept, a_todo
437 else if SFormula.is_false new_phi then
438 a_sat, StateSet.add q a_unsat, StateSet.add q a_rem, a_kept, a_todo
440 let new_tr = Transition.make (q, lab, new_phi) in
441 (a_sat, a_unsat, a_rem, StateSet.add q a_kept, (TransList.cons new_tr a_todo))
442 ) old_todo (old_sat, old_unsat, StateSet.empty, StateSet.empty, TransList.nil)
444 (* States that have been removed from the todo list and not kept are now
446 let unsat = StateSet.union unsat (StateSet.diff removed kept) in
447 (* States that were found once to be satisfiable remain so *)
448 let unsat = StateSet.diff unsat sat in
449 let new_config = Config.make { old_config.Config.node with sat; unsat; todo; } in
450 Cache.N4.add auto.cache4 oid fcsid nssid psid new_config;
453 if res == old_config then res else loop res
458 [add_trans a q labels f] adds a transition [(q,labels) -> f] to the
459 automaton [a] but ensures that transitions remains pairwise disjoint
462 let add_trans a q s f =
463 let trs = try Hashtbl.find a.transitions q with Not_found -> [] in
465 List.fold_left (fun (acup, atrs) (labs, phi) ->
466 let lab1 = QNameSet.inter labs s in
467 let lab2 = QNameSet.diff labs s in
469 if QNameSet.is_empty lab1 then []
470 else [ (lab1, SFormula.or_ phi f) ]
473 if QNameSet.is_empty lab2 then []
474 else [ (lab2, SFormula.or_ phi f) ]
476 (QNameSet.union acup labs, tr1@ tr2 @ atrs)
477 ) (QNameSet.empty, []) trs
479 let rem = QNameSet.diff s cup in
480 let ntrs = if QNameSet.is_empty rem then ntrs
481 else (rem, f) :: ntrs
483 Hashtbl.replace a.transitions q ntrs
485 let _pr_buff = Buffer.create 50
486 let _str_fmt = formatter_of_buffer _pr_buff
487 let _flush_str_fmt () = pp_print_flush _str_fmt ();
488 let s = Buffer.contents _pr_buff in
489 Buffer.clear _pr_buff; s
493 "Internal UID: %i@\n\
495 Selection states: %a@\n\
496 Alternating transitions:@\n"
498 StateSet.print a.states
499 StateSet.print a.selection_states;
502 (fun q t acc -> List.fold_left (fun acc (s , f) -> (q,s,f)::acc) acc t)
506 let sorted_trs = List.stable_sort (fun (q1, s1, _) (q2, s2, _) ->
507 let c = State.compare q1 q2 in - (if c == 0 then QNameSet.compare s1 s2 else c))
510 let _ = _flush_str_fmt () in
511 let strs_strings, max_pre, max_all = List.fold_left (fun (accl, accp, acca) (q, s, f) ->
512 let s1 = State.print _str_fmt q; _flush_str_fmt () in
513 let s2 = QNameSet.print _str_fmt s; _flush_str_fmt () in
514 let s3 = SFormula.print _str_fmt f; _flush_str_fmt () in
515 let pre = Pretty.length s1 + Pretty.length s2 in
516 let all = Pretty.length s3 in
517 ( (q, s1, s2, s3) :: accl, max accp pre, max acca all)
518 ) ([], 0, 0) sorted_trs
520 let line = Pretty.line (max_all + max_pre + 6) in
521 let prev_q = ref State.dummy in
522 fprintf fmt "%s@\n" line;
523 List.iter (fun (q, s1, s2, s3) ->
524 if !prev_q != q && !prev_q != State.dummy then fprintf fmt "%s@\n" line;
526 fprintf fmt "%s, %s" s1 s2;
527 fprintf fmt "%s" (Pretty.padding (max_pre - Pretty.length s1 - Pretty.length s2));
528 fprintf fmt " %s %s@\n" Pretty.right_arrow s3;
530 fprintf fmt "%s@\n" line
533 [complete transitions a] ensures that for each state q
534 and each symbols s in the alphabet, a transition q, s exists.
535 (adding q, s -> F when necessary).
538 let complete_transitions a =
539 StateSet.iter (fun q ->
540 let qtrans = Hashtbl.find a.transitions q in
542 List.fold_left (fun rem (labels, _) ->
543 QNameSet.diff rem labels) QNameSet.any qtrans
546 if QNameSet.is_empty rem then qtrans
548 (rem, SFormula.false_) :: qtrans
550 Hashtbl.replace a.transitions q nqtrans
553 let cleanup_states a =
554 let memo = ref StateSet.empty in
556 if not (StateSet.mem q !memo) then begin
557 memo := StateSet.add q !memo;
558 let trs = try Hashtbl.find a.transitions q with Not_found -> [] in
559 List.iter (fun (_, phi) ->
560 StateSet.iter loop (SFormula.get_states phi)) trs
563 StateSet.iter loop a.selection_states;
564 let unused = StateSet.diff a.states !memo in
565 StateSet.iter (fun q -> Hashtbl.remove a.transitions q) unused;
568 (* [normalize_negations a] removes negative atoms in the formula
569 complementing the sub-automaton in the negative states.
570 [TODO check the meaning of negative upward arrows]
573 let normalize_negations auto =
574 let memo_state = Hashtbl.create 17 in
575 let todo = Queue.create () in
577 match SFormula.expr f with
578 Formula.True | Formula.False -> if b then f else SFormula.not_ f
579 | Formula.Or(f1, f2) -> (if b then SFormula.or_ else SFormula.and_)(flip b f1) (flip b f2)
580 | Formula.And(f1, f2) -> (if b then SFormula.and_ else SFormula.or_)(flip b f1) (flip b f2)
581 | Formula.Atom(a) -> begin
582 let l, b', q = Atom.node a in
583 if q == State.dummy then if b then f else SFormula.not_ f
585 if b == b' then begin
586 (* a appears positively, either no negation or double negation *)
587 if not (Hashtbl.mem memo_state (q,b)) then Queue.add (q,true) todo;
588 SFormula.atom_ (Atom.make (l, true, q))
590 (* need to reverse the atom
591 either we have a positive state deep below a negation
592 or we have a negative state in a positive formula
593 b' = sign of the state
594 b = sign of the enclosing formula
598 (* does the inverted state of q exist ? *)
599 Hashtbl.find memo_state (q, false)
602 (* create a new state and add it to the todo queue *)
603 let nq = State.make () in
604 auto.states <- StateSet.add nq auto.states;
605 Hashtbl.add memo_state (q, false) nq;
606 Queue.add (q, false) todo; nq
608 SFormula.atom_ (Atom.make (l, true, not_q))
612 (* states that are not reachable from a selection stat are not interesting *)
613 StateSet.iter (fun q -> Queue.add (q, true) todo) auto.selection_states;
615 while not (Queue.is_empty todo) do
616 let (q, b) as key = Queue.pop todo in
619 Hashtbl.find memo_state key
622 let nq = if b then q else
623 let nq = State.make () in
624 auto.states <- StateSet.add nq auto.states;
627 Hashtbl.add memo_state key nq; nq
629 let trans = Hashtbl.find auto.transitions q in
630 let trans' = List.map (fun (lab, f) -> lab, flip b f) trans in
631 Hashtbl.replace auto.transitions q' trans';