1 (* Copyright (C) 2000, HELM Team.
3 * This file is part of HELM, an Hypertextual, Electronic
4 * Library of Mathematics, developed at the Computer Science
5 * Department, University of Bologna, Italy.
7 * HELM is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License
9 * as published by the Free Software Foundation; either version 2
10 * of the License, or (at your option) any later version.
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13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
17 * You should have received a copy of the GNU General Public License
18 * along with HELM; if not, write to the Free Software
19 * Foundation, Inc., 59 Temple Place - Suite 330, Boston,
22 * For details, see the HELM World-Wide-Web page,
23 * http://cs.unibo.it/helm/.
27 * implementazione del'interprete MathQL
53 "/" ^ (string_of_int j)
59 * inizializzazione della connessione al database
61 let init () = Dbconn.init ();;
63 (* execute_ex env q *)
64 (* [env] is the attributed uri environment in which the query [q] *)
65 (* must be evaluated *)
66 (* [q] is the query to evaluate *)
67 (* It returns a [Mathql_semantics.result] *)
68 let rec execute_ex env =
70 MQSelect (apvar, alist, abool) ->
71 select_ex env apvar (execute_ex env alist) abool
72 | MQUsedBy (alist, asvar) ->
73 use_ex (execute_ex env alist) asvar "F" (*"refObj"*)
74 | MQUse (alist, asvar) ->
75 use_ex (execute_ex env alist) asvar "B" (*"backPointer"*)
76 | MQPattern (apreamble, apattern, afragid) ->
77 pattern_ex apreamble apattern afragid
79 union_ex (execute_ex env l1) (execute_ex env l2)
82 diff_ex (execute_ex env l1) (execute_ex env l2)
83 | MQSortedBy (l, o, f) ->
84 sortedby_ex (execute_ex env l) o f
86 | MQIntersect (l1, l2) ->
87 intersect_ex (execute_ex env l1) (execute_ex env l2)
88 | MQRVarOccur rvar -> [List.assoc rvar env]
91 (* Let's initialize the execute in Select, creating a cyclical recursion *)
92 Select.execute := execute_ex;;
95 * converte il risultato interno di una query (uri + contesto)
96 * in un risultato di sole uri
99 * l: string list list;
104 * il tipo del risultato mantenuto internamente e' diverso dal tipo di risultato
105 * restituito in output poiche', mentre chi effettua le query vuole come risultato
106 * solo le eventuali uri che soddisfano le query stesse, internamente ad una uri
107 * sono associati anche i valori delle variabili che ancora non sono state valutate
108 * perche', ad esempio, si trovano in altri rami dell'albero.
111 * SELECT x IN USE PATTERN "cic:/**.con" POSITION $a WHERE $a IS MainConclusion
112 * L'albero corrispondente a questa query e':
118 * PATTERN $a $a MainConclusion
120 * Nel momento in cui si esegue il ramo USE non sono noti i vincoli sullla variabile $a
121 * percui e' necessario considerare, oltre alle uri, i valori della variabile per i quali
122 * la uri puo' far parte del risultato.
125 let tmp = List.map (function {Mathql_semantics.uri = uri} -> uri) l in
129 match Str.split (Str.regexp ":\|#\|/") l with
131 match List.rev tl with
132 ")"::n::"xpointer(1"::tail ->
139 | _ -> (MQString t) :: MQSlash :: par
143 (Some (int_of_string n), None)
145 | ")"::n::m::"xpointer(1"::tail ->
152 | _ -> (MQString t) :: MQSlash :: par
156 (Some (int_of_string m), Some (int_of_string n))
165 | _ -> (MQString t) :: MQSlash :: par
184 MQList qq -> xres_to_res (execute_ex [] qq)
188 * chiusura della connessione al database
190 let close () = Dbconn.close ();;