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 2013-04-04 18:46:50 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
164 mutable states : StateSet.t;
165 mutable selection_states: StateSet.t;
166 transitions: (State.t, (QNameSet.t*SFormula.t) list) Hashtbl.t;
167 mutable cache2 : TransList.t Cache.N2.t;
168 mutable cache6 : (TransList.t*StateSet.t) Cache.N6.t;
171 let next = Uid.make_maker ()
173 let dummy2 = TransList.cons
174 (Transition.make (State.dummy,QNameSet.empty, SFormula.false_))
177 let dummy6 = (dummy2, StateSet.empty)
180 let create s ss = { id = next ();
182 selection_states = ss;
183 transitions = Hashtbl.create 17;
184 cache2 = Cache.N2.create dummy2;
185 cache6 = Cache.N6.create dummy6;
189 a.cache2 <- Cache.N2.create dummy2;
190 a.cache6 <- Cache.N6.create dummy6
193 let get_trans_aux a tag states =
194 StateSet.fold (fun q acc0 ->
196 let trs = Hashtbl.find a.transitions q in
197 List.fold_left (fun acc1 (labs, phi) ->
198 if QNameSet.mem tag labs then TransList.cons (Transition.make (q, labs, phi)) acc1 else acc1) acc0 trs
199 with Not_found -> acc0
200 ) states TransList.nil
203 let get_trans a tag states =
205 Cache.N2.find a.cache2
206 (tag.QName.id :> int) (states.StateSet.id :> int)
208 if trs == dummy2 then
209 let trs = get_trans_aux a tag states in
212 (tag.QName.id :> int)
213 (states.StateSet.id :> int) trs; trs)
218 let eval_form phi fcs nss ps ss is_left is_right has_left has_right kind =
220 begin match SFormula.expr phi with
222 | Formula.False -> false
224 let p, b, q = Atom.node a in
227 | First_child -> StateSet.mem q fcs
228 | Next_sibling -> StateSet.mem q nss
229 | Parent | Previous_sibling -> StateSet.mem q ps
230 | Stay -> StateSet.mem q ss
231 | Is_first_child -> is_left
232 | Is_next_sibling -> is_right
234 | Has_first_child -> has_left
235 | Has_next_sibling -> has_right
237 if is_move p && (not b) then
238 eprintf "Warning: Invalid negative atom %a" Atom.print a;
240 | Formula.And(phi1, phi2) -> loop phi1 && loop phi2
241 | Formula.Or (phi1, phi2) -> loop phi1 || loop phi2
246 let int_of_conf is_left is_right has_left has_right kind =
247 ((Obj.magic kind) lsl 4) lor
248 ((Obj.magic is_left) lsl 3) lor
249 ((Obj.magic is_right) lsl 2) lor
250 ((Obj.magic has_left) lsl 1) lor
251 (Obj.magic has_right)
253 let eval_trans auto ltrs fcs nss ps ss is_left is_right has_left has_right kind =
254 let i = int_of_conf is_left is_right has_left has_right kind
255 and k = (fcs.StateSet.id :> int)
256 and l = (nss.StateSet.id :> int)
257 and m = (ps.StateSet.id :> int)
260 let rec loop ltrs ss =
261 let j = (ltrs.TransList.id :> int)
262 and n = (ss.StateSet.id :> int) in
263 let (new_ltrs, new_ss) as res =
264 let res = Cache.N6.find auto.cache6 i j k l m n in
265 if res == dummy6 then
267 TransList.fold (fun trs (acct, accs) ->
268 let q, _, phi = Transition.node trs in
269 if StateSet.mem q accs then (acct, accs) else
272 is_left is_right has_left has_right kind
274 (acct, StateSet.add q accs)
276 (TransList.cons trs acct, accs)
277 ) ltrs (TransList.nil, ss)
279 Cache.N6.add auto.cache6 i j k l m n res; res
283 if new_ss == ss then res else
293 [add_trans a q labels f] adds a transition [(q,labels) -> f] to the
294 automaton [a] but ensures that transitions remains pairwise disjoint
297 let add_trans a q s f =
298 let trs = try Hashtbl.find a.transitions q with Not_found -> [] in
300 List.fold_left (fun (acup, atrs) (labs, phi) ->
301 let lab1 = QNameSet.inter labs s in
302 let lab2 = QNameSet.diff labs s in
304 if QNameSet.is_empty lab1 then []
305 else [ (lab1, SFormula.or_ phi f) ]
308 if QNameSet.is_empty lab2 then []
309 else [ (lab2, SFormula.or_ phi f) ]
311 (QNameSet.union acup labs, tr1@ tr2 @ atrs)
312 ) (QNameSet.empty, []) trs
314 let rem = QNameSet.diff s cup in
315 let ntrs = if QNameSet.is_empty rem then ntrs
316 else (rem, f) :: ntrs
318 Hashtbl.replace a.transitions q ntrs
320 let _pr_buff = Buffer.create 50
321 let _str_fmt = formatter_of_buffer _pr_buff
322 let _flush_str_fmt () = pp_print_flush _str_fmt ();
323 let s = Buffer.contents _pr_buff in
324 Buffer.clear _pr_buff; s
328 "\nInternal UID: %i@\n\
330 Selection states: %a@\n\
331 Alternating transitions:@\n"
333 StateSet.print a.states
334 StateSet.print a.selection_states;
337 (fun q t acc -> List.fold_left (fun acc (s , f) -> (q,s,f)::acc) acc t)
341 let sorted_trs = List.stable_sort (fun (q1, s1, _) (q2, s2, _) ->
342 let c = State.compare q1 q2 in - (if c == 0 then QNameSet.compare s1 s2 else c))
345 let _ = _flush_str_fmt () in
346 let strs_strings, max_pre, max_all = List.fold_left (fun (accl, accp, acca) (q, s, f) ->
347 let s1 = State.print _str_fmt q; _flush_str_fmt () in
348 let s2 = QNameSet.print _str_fmt s; _flush_str_fmt () in
349 let s3 = SFormula.print _str_fmt f; _flush_str_fmt () in
350 let pre = Pretty.length s1 + Pretty.length s2 in
351 let all = Pretty.length s3 in
352 ( (q, s1, s2, s3) :: accl, max accp pre, max acca all)
353 ) ([], 0, 0) sorted_trs
355 let line = Pretty.line (max_all + max_pre + 6) in
356 let prev_q = ref State.dummy in
357 List.iter (fun (q, s1, s2, s3) ->
358 if !prev_q != q && !prev_q != State.dummy then fprintf fmt " %s\n%!" line;
360 fprintf fmt " %s, %s" s1 s2;
361 fprintf fmt "%s" (Pretty.padding (max_pre - Pretty.length s1 - Pretty.length s2));
362 fprintf fmt " %s %s@\n%!" Pretty.right_arrow s3;
364 fprintf fmt " %s\n%!" line
367 [complete transitions a] ensures that for each state q
368 and each symbols s in the alphabet, a transition q, s exists.
369 (adding q, s -> F when necessary).
372 let complete_transitions a =
373 StateSet.iter (fun q ->
374 let qtrans = Hashtbl.find a.transitions q in
376 List.fold_left (fun rem (labels, _) ->
377 QNameSet.diff rem labels) QNameSet.any qtrans
380 if QNameSet.is_empty rem then qtrans
382 (rem, SFormula.false_) :: qtrans
384 Hashtbl.replace a.transitions q nqtrans
387 let cleanup_states a =
388 let memo = ref StateSet.empty in
390 if not (StateSet.mem q !memo) then begin
391 memo := StateSet.add q !memo;
392 let trs = try Hashtbl.find a.transitions q with Not_found -> [] in
393 List.iter (fun (_, phi) ->
394 StateSet.iter loop (SFormula.get_states phi)) trs
397 StateSet.iter loop a.selection_states;
398 let unused = StateSet.diff a.states !memo in
399 eprintf "Unused states %a\n%!" StateSet.print unused;
400 StateSet.iter (fun q -> Hashtbl.remove a.transitions q) unused;
403 (* [normalize_negations a] removes negative atoms in the formula
404 complementing the sub-automaton in the negative states.
405 [TODO check the meaning of negative upward arrows]
408 let normalize_negations auto =
409 eprintf "Automaton before normalize_trans:\n";
410 print err_formatter auto;
411 eprintf "--------------------\n%!";
413 let memo_state = Hashtbl.create 17 in
414 let todo = Queue.create () in
416 match SFormula.expr f with
417 Formula.True | Formula.False -> if b then f else SFormula.not_ f
418 | Formula.Or(f1, f2) -> (if b then SFormula.or_ else SFormula.and_)(flip b f1) (flip b f2)
419 | Formula.And(f1, f2) -> (if b then SFormula.and_ else SFormula.or_)(flip b f1) (flip b f2)
420 | Formula.Atom(a) -> begin
421 let l, b', q = Atom.node a in
422 if q == State.dummy then if b then f else SFormula.not_ f
424 if b == b' then begin
425 (* a appears positively, either no negation or double negation *)
426 if not (Hashtbl.mem memo_state (q,b)) then Queue.add (q,true) todo;
427 SFormula.atom_ (Atom.make (l, true, q))
429 (* need to reverse the atom
430 either we have a positive state deep below a negation
431 or we have a negative state in a positive formula
432 b' = sign of the state
433 b = sign of the enclosing formula
437 (* does the inverted state of q exist ? *)
438 Hashtbl.find memo_state (q, false)
441 (* create a new state and add it to the todo queue *)
442 let nq = State.make () in
443 auto.states <- StateSet.add nq auto.states;
444 Hashtbl.add memo_state (q, false) nq;
445 Queue.add (q, false) todo; nq
447 SFormula.atom_ (Atom.make (l, true, not_q))
451 (* states that are not reachable from a selection stat are not interesting *)
452 StateSet.iter (fun q -> Queue.add (q, true) todo) auto.selection_states;
454 while not (Queue.is_empty todo) do
455 let (q, b) as key = Queue.pop todo in
458 Hashtbl.find memo_state key
461 let nq = if b then q else
462 let nq = State.make () in
463 auto.states <- StateSet.add nq auto.states;
466 Hashtbl.add memo_state key nq; nq
468 let trans = Hashtbl.find auto.transitions q in
469 let trans' = List.map (fun (lab, f) -> lab, flip b f) trans in
470 Hashtbl.replace auto.transitions q' trans';