(* *)
(* TAToo *)
(* *)
-(* Lucca Hirschi, ? *)
-(* ? *)
+(* Lucca Hirschi, LRI UMR8623 *)
+(* Université Paris-Sud & CNRS *)
(* *)
(* Copyright 2010-2012 Université Paris-Sud and Centre National de la *)
(* Recherche Scientifique. All rights reserved. This file is *)
(* *)
(***********************************************************************)
-let trad qu = Asta.dummy
+open XPath.Ast
+open Formula.Infix
+
+exception Not_core_XPath
+(** Raised whenever the XPath query contains not implemented structures *)
+
+let pr_er = Format.err_formatter
+
+let trans query =
+ (* Buidling of the ASTA step by step with a special case for the last
+ step. Then add a top most state. Each function modifies asta. *)
+ let asta = Asta.empty in
+ (* builds asta from the bottom of the query *)
+ let rec trans = function
+ | [s] -> trans_last s
+ | s :: tl -> trans tl; trans_step s
+ | [] -> ()
+
+ (* Add THE top most state for top-level query (done in the end) *)
+ and trans_init () =
+ let top_st = Asta.new_state () in
+ let or_top =
+ List.fold_left (fun acc x -> ((`Left *+ x) +| acc))
+ (Formula.false_) (Asta.top_states asta)
+ in
+ Asta.add_quer asta top_st;
+ Asta.init_top asta;
+ Asta.add_top asta top_st;
+ Asta.add_bot asta top_st; (* for trees which are leaves *)
+ Asta.add_tr asta (top_st, Asta.any_label, or_top) true
+
+ (* A selecting state is needed *)
+ and trans_last (ax,test,pred) =
+ let fo_p = trans_pr pred in
+ let q,q' = Asta.new_state(), Asta.new_state() in
+ Asta.add_selec asta q';
+ Asta.add_quer asta q;
+ Asta.add_quer asta q';
+ Asta.add_top asta q;
+ Asta.add_top asta q';
+ Asta.add_bot asta q; (* q' \notin B !! *)
+ let Simple lab = test in
+ let tr_selec = (q', lab, fo_p)
+ and tr_q = (q, Asta.any_label, form_propa_selec q q' ax) in
+ Asta.add_tr asta tr_selec true;
+ Asta.add_tr asta tr_q true
+
+ (* Add a new state and its transitions for the step *)
+ and trans_step (ax,test,pred) =
+ let fo_p = trans_pr pred
+ and q = Asta.new_state() in
+ let Simple label = test
+ and form_next = (fo_p) *& (* (\/ top_next) /\ predicat *)
+ (List.fold_left (fun acc x -> (`Left *+ x ) +| acc)
+ Formula.false_ (Asta.top_states asta)) in
+ let tr_next = (q, label, form_next)
+ and tr_propa = (q, Asta.any_label, form_propa q ax) in
+ Asta.add_quer asta q;
+ Asta.add_top asta q;
+ Asta.add_bot asta q;
+ Asta.add_tr asta tr_next true;
+ Asta.add_tr asta tr_propa true;
+ Asta.init_top asta;
+ Asta.add_top asta q
+
+ (* Translating of predicates. Either we apply De Morgan rules
+ in xPath.parse or here *)
+ and trans_pr = function
+ | Expr True -> Formula.true_
+ | Expr False -> Formula.false_
+ | Or (p_1,p_2) -> trans_pr(p_1) +| trans_pr(p_2)
+ | And (p_1,p_2) -> trans_pr(p_1) *& trans_pr(p_2)
+ | Not (Expr Path q) -> (trans_pr_path false q)
+ | Expr Path q -> (trans_pr_path true q)
+ | x -> print_predicate pr_er x; raise Not_core_XPath
+
+ (* Builds asta for predicate and gives the formula which must be satsified *)
+ and trans_pr_path posi = function
+ | Relative [] -> if posi then Formula.true_ else Formula.false_
+ | Relative steps -> List.fold_left
+ (fun acc x -> if posi then (`Left *+ x) +| acc else (`Left *- x) +| acc)
+ Formula.false_ (trans_pr_step_l steps)
+ | AbsoluteDoS steps as x -> print pr_er x; raise Not_core_XPath
+ | Absolute steps as x -> print pr_er x; raise Not_core_XPath
+
+ (* Builds asta for a predicate query and give the formula *)
+ and trans_pr_step_l = function
+ | [step] -> trans_pr_step [] step
+ | step :: tl -> let list_top = trans_pr_step_l tl in
+ trans_pr_step list_top step
+ | [] -> failwith "Can not happened! 1"
+
+ (* Add a step on the top of a list of states in a predicate *)
+ and trans_pr_step list (ax,test,pred) =
+ let form_next =
+ if list = []
+ then trans_pr pred
+ else (trans_pr pred) *&
+ (List.fold_left (fun acc x -> (`Left *+ x) +| acc)
+ Formula.false_ list)
+ and q = Asta.new_state()
+ and Simple label = test in
+ let tr_next = (q,label, form_next)
+ and tr_propa = (q, Asta.any_label, form_propa q ax) in
+ Asta.add_reco asta q;
+ Asta.add_tr asta tr_next false;
+ Asta.add_tr asta tr_propa false;
+ [q] (* always one element here, but more with self
+ axis *)
+ (* Gives the propagation formula *)
+ and form_propa q = function
+ | Child -> `Right *+ q
+ | Descendant -> (`Left *+ q +| `Right *+ q)
+ | x -> print_axis pr_er x; raise Not_core_XPath
+
+ (* The same with a selecting state *)
+ and form_propa_selec q q' = function
+ | Child -> `Right *+ q +| `Right *+ q'
+ | Descendant -> (`Left *+ q +| `Right *+ q) +| (`Left *+ q' +| `Right *+ q')
+ | x -> print_axis pr_er x; raise Not_core_XPath
+
+ in
+ (* Match the top-level query *)
+ match query with
+ | Absolute steps -> trans steps; trans_init(); asta
+ | AbsoluteDoS steps as x -> print pr_er x; raise Not_core_XPath
+ | Relative steps as x -> print pr_er x; raise Not_core_XPath
projects / tatoo.git / blobdiff