1/* Part of SWI-Prolog 2 3 Author: Jan Wielemaker 4 E-mail: J.Wielemaker@vu.nl 5 WWW: http://www.swi-prolog.org 6 Copyright (c) 2010-2013, University of Amsterdam 7 All rights reserved. 8 9 Redistribution and use in source and binary forms, with or without 10 modification, are permitted provided that the following conditions 11 are met: 12 13 1. Redistributions of source code must retain the above copyright 14 notice, this list of conditions and the following disclaimer. 15 16 2. Redistributions in binary form must reproduce the above copyright 17 notice, this list of conditions and the following disclaimer in 18 the documentation and/or other materials provided with the 19 distribution. 20 21 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 22 "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 23 LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 24 FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 25 COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 26 INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 27 BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 28 LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER 29 CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN 31 ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 32 POSSIBILITY OF SUCH DAMAGE. 33*/ 34 35:- module(rdf_ntriples_old, 36 [ load_rdf_ntriples/2, % +File, -Triples 37 rdf_ntriple_part/4 % +Field, -Value, <DCG> 38 ]).

RDF N-triples parser (obsolete)

This module parses n-triple files as defined by the W3C RDF working in http://www.w3.org/TR/rdf-testcases/#ntriples. This format is a simplified version of the RDF N3 notation used in the *.nt files that are used to describe the normative outcome of the RDF test-cases.

The returned list terms are of the form

rdf(Subject, Predicate, Object)

where

Subject: is an atom or node(Id) for anonymous nodes
Predicate: is an atom
Object: is an atom, node(Id), literal(Atom) or xml(Atom)

deprecated: - This library will shortly be replaced with a stub that calls library(semweb/rdf_ntriples). */

65% load_rdf_ntriples(+Source, -Triples) 66% 67% Load a file or stream to a list of rdf(S,P,O) triples. 68 69load_rdf_ntriples(File, Triples) :- 70 open_nt_file(File, In, Close), 71 call_cleanup(stream_to_triples(In, Triples), Close). 72 73% open_nt_file(+Input, -Stream, -Close) 74% 75% Open Input, returning Stream and a goal to cleanup Stream if it 76% was opened. 77 78open_nt_file(stream(Stream), Stream, true) :- !. 79open_nt_file(Stream, Stream, true) :- 80 is_stream(Stream), 81 !. 82open_nt_file(Spec, Stream, close(Stream)) :- 83 absolute_file_name(Spec, 84 [ access(read), 85 extensions([nt,'']) 86 ], Path), 87 open(Path, read, Stream). 88 89 90% rdf_ntriple_part(+Type, -Value, <DCG>) 91% 92% Parse one of the fields of an ntriple. This is used for the 93% SWI-Prolog Sesame (www.openrdf.org) implementation to realise 94% /servlets/removeStatements. I do not think public use of this 95% predicate should be stimulated. 96 97rdf_ntriple_part(subject, Subject) --> 98 subject(Subject). 99rdf_ntriple_part(predicate, Predicate) --> 100 predicate(Predicate). 101rdf_ntriple_part(object, Object) --> 102 predicate(Object). 103 104 105% stream_to_triples(+Stream, -ListOfTriples) 106% 107% Read Stream, returning all its triples 108 109stream_to_triples(In, Triples) :- 110 read_line_to_codes(In, Line), 111 ( Line == end_of_file 112 -> Triples = [] 113 ; phrase(line(Triples, Tail), Line), 114 stream_to_triples(In, Tail) 115 ). 116 117line(Triples, Tail) --> 118 wss, 119 ( comment 120 -> {Triples = Tail} 121 ; triple(Triple) 122 -> {Triples = [Triple|Tail]} 123 ). 124 125comment --> 126 "#", 127 !, 128 skip_rest. 129comment --> 130 end_of_input. 131 132triple(rdf(Subject, Predicate, Object)) --> 133 subject(Subject), ws, wss, 134 predicate(Predicate), ws, wss, 135 object(Object), wss, ".", wss. 136 137subject(Subject) --> 138 uniref(Subject), 139 !. 140subject(Subject) --> 141 node_id(Subject). 142 143predicate(Predicate) --> 144 uniref(Predicate). 145 146object(Object) --> 147 uniref(Object), 148 !. 149object(Object) --> 150 node_id(Object). 151object(Object) --> 152 literal(Object). 153 154 155uniref(URI) --> 156 "<", 157 escaped_uri_codes(Codes), 158 ">", 159 !, 160 { atom_codes(URI, Codes) 161 }. 162 163node_id(node(Id)) --> % anonymous nodes 164 "_:", 165 name_start(C0), 166 name_codes(Codes), 167 { atom_codes(Id, [C0|Codes]) 168 }. 169 170literal(Literal) --> 171 lang_string(Literal), 172 !. 173literal(Literal) --> 174 xml_string(Literal). 175 176 177% name_start(-Code) 178% name_codes(-ListfCodes) 179% 180% Parse identifier names 181 182name_start(C) --> 183 [C], 184 { code_type(C, alpha) 185 }. 186 187name_codes([C|T]) --> 188 [C], 189 { code_type(C, alnum) 190 }, 191 !, 192 name_codes(T). 193name_codes([]) --> 194 []. 195 196 197% escaped_uri_codes(-CodeList) 198% 199% Decode string holding %xx escaped characters. 200 201escaped_uri_codes([]) --> 202 []. 203escaped_uri_codes([C|T]) --> 204 "%", [D0,D1], 205 { code_type(D0, xdigit(V0)), 206 code_type(D1, xdigit(V1)), 207 !, 208 C is V0<<4 + V1 209 }, 210 escaped_uri_codes(T). 211escaped_uri_codes([C|T]) --> 212 "\\u", [D0,D1,D2,D3], 213 !, 214 { code_type(D0, xdigit(V0)), 215 code_type(D1, xdigit(V1)), 216 code_type(D2, xdigit(V2)), 217 code_type(D3, xdigit(V3)), 218 C is V0<<12 + V1<<8 + V2<<4 + V3 219 }, 220 escaped_uri_codes(T). 221escaped_uri_codes([C|T]) --> 222 "\\U", [D0,D1,D2,D3,D4,D5,D6,D7], 223 !, 224 { code_type(D0, xdigit(V0)), 225 code_type(D1, xdigit(V1)), 226 code_type(D2, xdigit(V2)), 227 code_type(D3, xdigit(V3)), 228 code_type(D4, xdigit(V4)), 229 code_type(D5, xdigit(V5)), 230 code_type(D6, xdigit(V6)), 231 code_type(D7, xdigit(V7)), 232 C is V0<<28 + V1<<24 + V2<<20 + V3<<16 + 233 V4<<12 + V5<<8 + V6<<4 + V7 234 }, 235 escaped_uri_codes(T). 236escaped_uri_codes([C|T]) --> 237 [C], 238 escaped_uri_codes(T). 239 240 241% lang_string() 242% 243% Process a language string 244 245lang_string(String) --> 246 "\"", 247 string(Codes), 248 "\"", 249 !, 250 { atom_codes(Atom, Codes) 251 }, 252 ( langsep 253 -> language(Lang), 254 { String = literal(lang(Lang, Atom)) 255 } 256 ; "^^" 257 -> uniref(Type), 258 { String = literal(type(Type, Atom)) 259 } 260 ; { String = literal(Atom) 261 } 262 ). 263 264langsep --> 265 "-". 266langsep --> 267 "@". 268 269% xml_string(String) 270% 271% Handle xml"..." 272 273xml_string(xml(String)) --> 274 "xml\"", % really no whitespace? 275 string(Codes), 276 "\"", 277 { atom_codes(String, Codes) 278 }. 279 280string([]) --> 281 []. 282string([C0|T]) --> 283 string_char(C0), 284 string(T). 285 286string_char(0'\\) --> 287 "\\\\". 288string_char(0'") --> 289 "\\\"". 290string_char(10) --> 291 "\\n". 292string_char(13) --> 293 "\\r". 294string_char(9) --> 295 "\\t". 296string_char(C) --> 297 "\\u", 298 '4xdigits'(C). 299string_char(C) --> 300 "\\U", 301 '4xdigits'(C0), 302 '4xdigits'(C1), 303 { C is C0<<16 + C1 304 }. 305string_char(C) --> 306 [C]. 307 308'4xdigits'(C) --> 309 [C0,C1,C2,C3], 310 { code_type(C0, xdigit(V0)), 311 code_type(C1, xdigit(V1)), 312 code_type(C2, xdigit(V2)), 313 code_type(C3, xdigit(V3)), 314 315 C is V0<<12 + V1<<8 + V2<<4 + V3 316 }. 317 318% language(-Lang) 319% 320% Return xml:lang language identifier. 321 322language(Lang) --> 323 lang_code(C0), 324 lang_codes(Codes), 325 { atom_codes(Lang, [C0|Codes]) 326 }. 327 328lang_code(C) --> 329 [C], 330 { C \== 0'., 331 \+ code_type(C, white) 332 }. 333 334lang_codes([C|T]) --> 335 lang_code(C), 336 !, 337 lang_codes(T). 338lang_codes([]) --> 339 []. 340 341 342 /******************************* 343 * BASICS * 344 *******************************/ 345 346skip_rest(_,[]). 347 348ws --> 349 [C], 350 { code_type(C, white) 351 }. 352 353end_of_input([], []). 354 355 356wss --> 357 ws, 358 !, 359 wss. 360wss --> 361 []