34
35:- module(rdf_ntriples_old,
36 [ load_rdf_ntriples/2, 37 rdf_ntriple_part/4 38 ]). 39
40
64
68
69load_rdf_ntriples(File, Triples) :-
70 open_nt_file(File, In, Close),
71 call_cleanup(stream_to_triples(In, Triples), Close).
72
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
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
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
-->
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)) --> 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
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
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
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
272
273xml_string(xml(String)) -->
274 "xml\"", 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
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
342 345
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 []