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 2013-03-13 18:31:19 CET by Kim Nguyen>
24 type predicate = | First_child
31 | Is of (Tree.Common.NodeKind.t)
35 let is_move p = match p with
36 | First_child | Next_sibling
37 | Parent | Previous_sibling | Stay -> true
41 type atom = predicate * bool * State.t
43 module Atom : (Formula.ATOM with type data = atom) =
49 let equal n1 n2 = n1 = n2
50 let hash n = Hashtbl.hash n
53 include Hcons.Make(Node)
56 let p, b, q = a.node in
57 if not b then fprintf ppf "%s" Pretty.lnot;
59 | First_child -> fprintf ppf "FC(%a)" State.print q
60 | Next_sibling -> fprintf ppf "NS(%a)" State.print q
61 | Parent -> fprintf ppf "FC%s(%a)" Pretty.inverse State.print q
62 | Previous_sibling -> fprintf ppf "NS%s(%a)" Pretty.inverse State.print q
63 | Stay -> fprintf ppf "%s(%a)" Pretty.epsilon State.print q
64 | Is_first_child -> fprintf ppf "FC%s?" Pretty.inverse
65 | Is_next_sibling -> fprintf ppf "NS%s?" Pretty.inverse
66 | Is k -> fprintf ppf "is-%a?" Tree.Common.NodeKind.print k
67 | Has_first_child -> fprintf ppf "FC?"
68 | Has_next_sibling -> fprintf ppf "NS?"
71 let p, b, q = a.node in
79 include Formula.Make(Atom)
80 open Tree.Common.NodeKind
81 let mk_atom a b c = atom_ (Atom.make (a,b,c))
82 let mk_kind k = mk_atom (Is k) true State.dummy
84 (mk_atom Has_first_child true State.dummy)
86 let has_next_sibling =
87 (mk_atom Has_next_sibling true State.dummy)
90 (mk_atom Is_first_child true State.dummy)
93 (mk_atom Is_next_sibling true State.dummy)
96 (mk_atom (Is Attribute) true State.dummy)
99 (mk_atom (Is Element) true State.dummy)
101 let is_processing_instruction =
102 (mk_atom (Is ProcessingInstruction) true State.dummy)
105 (mk_atom (Is Comment) true State.dummy)
109 (mk_atom First_child true q)
114 (mk_atom Next_sibling true q)
119 (mk_atom Parent true q)
122 let previous_sibling q =
124 (mk_atom Previous_sibling true q)
128 (mk_atom Stay true q)
133 | Formula.Atom a -> let _, _, q = Atom.node a in
134 if q != State.dummy then StateSet.add q acc else acc
142 mutable states : StateSet.t;
143 mutable selection_states: StateSet.t;
144 transitions: (State.t, (QNameSet.t*SFormula.t) list) Hashtbl.t;
147 let next = Uid.make_maker ()
149 let create () = { id = next ();
150 states = StateSet.empty;
151 selection_states = StateSet.empty;
152 transitions = Hashtbl.create 17;
156 module Transition = Hcons.Make (struct
157 type t = State.t * QNameSet.t * SFormula.t
158 let equal (a, b, c) (d, e, f) =
159 a == d && b == e && c == f
161 HASHINT4 (PRIME1, a, ((QNameSet.uid b) :> int), ((SFormula.uid c) :> int))
164 module TransList : Hlist.S with type elt = Transition.t = Hlist.Make(Transition)
166 let get_trans a states tag =
167 StateSet.fold (fun q acc0 ->
169 let trs = Hashtbl.find a.transitions q in
170 List.fold_left (fun acc1 (labs, phi) ->
171 if QNameSet.mem tag labs then TransList.cons (Transition.make (q, labs, phi)) acc1 else acc1) acc0 trs
172 with Not_found -> acc0
173 ) states TransList.nil
176 [add_trans a q labels f] adds a transition [(q,labels) -> f] to the
177 automaton [a] but ensures that transitions remains pairwise disjoint
180 let add_trans a q s f =
181 let trs = try Hashtbl.find a.transitions q with Not_found -> [] in
183 List.fold_left (fun (acup, atrs) (labs, phi) ->
184 let lab1 = QNameSet.inter labs s in
185 let lab2 = QNameSet.diff labs s in
187 if QNameSet.is_empty lab1 then []
188 else [ (lab1, SFormula.or_ phi f) ]
191 if QNameSet.is_empty lab2 then []
192 else [ (lab2, SFormula.or_ phi f) ]
194 (QNameSet.union acup labs, tr1@ tr2 @ atrs)
195 ) (QNameSet.empty, []) trs
197 let rem = QNameSet.diff s cup in
198 let ntrs = if QNameSet.is_empty rem then ntrs
199 else (rem, f) :: ntrs
201 Hashtbl.replace a.transitions q ntrs
203 let _pr_buff = Buffer.create 50
204 let _str_fmt = formatter_of_buffer _pr_buff
205 let _flush_str_fmt () = pp_print_flush _str_fmt ();
206 let s = Buffer.contents _pr_buff in
207 Buffer.clear _pr_buff; s
211 "\nInternal UID: %i@\n\
213 Selection states: %a@\n\
214 Alternating transitions:@\n"
216 StateSet.print a.states
217 StateSet.print a.selection_states;
220 (fun q t acc -> List.fold_left (fun acc (s , f) -> (q,s,f)::acc) acc t)
224 let sorted_trs = List.stable_sort (fun (q1, s1, _) (q2, s2, _) ->
225 let c = State.compare q1 q2 in - (if c == 0 then QNameSet.compare s1 s2 else c))
228 let _ = _flush_str_fmt () in
229 let strs_strings, max_pre, max_all = List.fold_left (fun (accl, accp, acca) (q, s, f) ->
230 let s1 = State.print _str_fmt q; _flush_str_fmt () in
231 let s2 = QNameSet.print _str_fmt s; _flush_str_fmt () in
232 let s3 = SFormula.print _str_fmt f; _flush_str_fmt () in
233 let pre = Pretty.length s1 + Pretty.length s2 in
234 let all = Pretty.length s3 in
235 ( (q, s1, s2, s3) :: accl, max accp pre, max acca all)
236 ) ([], 0, 0) sorted_trs
238 let line = Pretty.line (max_all + max_pre + 6) in
239 let prev_q = ref State.dummy in
240 List.iter (fun (q, s1, s2, s3) ->
241 if !prev_q != q && !prev_q != State.dummy then fprintf fmt " %s\n%!" line;
243 fprintf fmt " %s, %s" s1 s2;
244 fprintf fmt "%s" (Pretty.padding (max_pre - Pretty.length s1 - Pretty.length s2));
245 fprintf fmt " %s %s@\n%!" Pretty.right_arrow s3;
247 fprintf fmt " %s\n%!" line
250 [complete transitions a] ensures that for each state q
251 and each symbols s in the alphabet, a transition q, s exists.
252 (adding q, s -> F when necessary).
255 let complete_transitions a =
256 StateSet.iter (fun q ->
257 let qtrans = Hashtbl.find a.transitions q in
259 List.fold_left (fun rem (labels, _) ->
260 QNameSet.diff rem labels) QNameSet.any qtrans
263 if QNameSet.is_empty rem then qtrans
265 (rem, SFormula.false_) :: qtrans
267 Hashtbl.replace a.transitions q nqtrans
270 let cleanup_states a =
271 let memo = ref StateSet.empty in
273 if not (StateSet.mem q !memo) then begin
274 memo := StateSet.add q !memo;
275 let trs = try Hashtbl.find a.transitions q with Not_found -> [] in
276 List.iter (fun (_, phi) ->
277 StateSet.iter loop (SFormula.get_states phi)) trs
280 StateSet.iter loop a.selection_states;
281 let unused = StateSet.diff a.states !memo in
282 eprintf "Unused states %a\n%!" StateSet.print unused;
283 StateSet.iter (fun q -> Hashtbl.remove a.transitions q) unused;
286 (* [normalize_negations a] removes negative atoms in the formula
287 complementing the sub-automaton in the negative states.
288 [TODO check the meaning of negative upward arrows]
291 let normalize_negations auto =
292 eprintf "Automaton before normalize_trans:\n";
293 print err_formatter auto;
294 eprintf "--------------------\n%!";
296 let memo_state = Hashtbl.create 17 in
297 let todo = Queue.create () in
299 match SFormula.expr f with
300 Formula.True | Formula.False -> if b then f else SFormula.not_ f
301 | Formula.Or(f1, f2) -> (if b then SFormula.or_ else SFormula.and_)(flip b f1) (flip b f2)
302 | Formula.And(f1, f2) -> (if b then SFormula.and_ else SFormula.or_)(flip b f1) (flip b f2)
303 | Formula.Atom(a) -> begin
304 let l, b', q = Atom.node a in
305 if q == State.dummy then if b then f else SFormula.not_ f
307 if b == b' then begin
308 (* a appears positively, either no negation or double negation *)
309 if not (Hashtbl.mem memo_state (q,b)) then Queue.add (q,true) todo;
310 SFormula.atom_ (Atom.make (l, true, q))
312 (* need to reverse the atom
313 either we have a positive state deep below a negation
314 or we have a negative state in a positive formula
315 b' = sign of the state
316 b = sign of the enclosing formula
320 (* does the inverted state of q exist ? *)
321 Hashtbl.find memo_state (q, false)
324 (* create a new state and add it to the todo queue *)
325 let nq = State.make () in
326 auto.states <- StateSet.add nq auto.states;
327 Hashtbl.add memo_state (q, false) nq;
328 Queue.add (q, false) todo; nq
330 SFormula.atom_ (Atom.make (l, true, not_q))
334 (* states that are not reachable from a selection stat are not interesting *)
335 StateSet.iter (fun q -> Queue.add (q, true) todo) auto.selection_states;
337 while not (Queue.is_empty todo) do
338 let (q, b) as key = Queue.pop todo in
341 Hashtbl.find memo_state key
344 let nq = if b then q else
345 let nq = State.make () in
346 auto.states <- StateSet.add nq auto.states;
349 Hashtbl.add memo_state key nq; nq
351 let trans = Hashtbl.find auto.transitions q in
352 let trans' = List.map (fun (lab, f) -> lab, flip b f) trans in
353 Hashtbl.replace auto.transitions q' trans';