/* Part of SWI-Prolog
Author: Jan Wielemaker
E-mail: J.Wielemaker@vu.nl
WWW: http://www.swi-prolog.org
Copyright (c) 2003-2015, University of Amsterdam
VU University Amsterdam
All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions
are met:
1. Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
2. Redistributions in binary form must reproduce the above copyright
notice, this list of conditions and the following disclaimer in
the documentation and/or other materials provided with the
distribution.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
POSSIBILITY OF SUCH DAMAGE.
*/
:- module(rdfs,
[ rdfs_subproperty_of/2, % ?SubProperties, ?Property
rdfs_subclass_of/2, % ?SubClass, ?Class
rdfs_class_property/2, % +Class, ?Property
rdfs_individual_of/2, % ?Resource, ?Class
rdfs_label/2, % ?Resource, ?Label
rdfs_label/3, % ?Resource, ?Language, ?Label
rdfs_ns_label/2, % +Resource, -Label
rdfs_ns_label/3, % +Resource, ?Label, -Label
rdfs_member/2, % ?Object, +Set
rdfs_list_to_prolog_list/2, % +Set, -List
rdfs_assert_list/3, % +List, -Resource, +DB
rdfs_assert_list/2, % +List, -Resource
rdfs_find/5 % +String, +Dom, +Props, +Method, -Subj
]).
:- use_module(library(lists)).
:- use_module(rdf_db).
/** <module> RDFS handling
This module provides various primitives for more high-level handling of
RDF models from an RDFS viewpoint. Note that there exist two approaches
for languages on top of RDF:
* Provide new predicates according to the concept of the high
level language (used in this module)
* Extend rdf/3 relation with triples _implied_ by the high-level
semantics. This approach is taken by ClioPatria.
*/
/*******************************
* EXPANSION *
*******************************/
:- rdf_meta
rdfs_subproperty_of(r,r),
rdfs_subclass_of(r,r),
rdfs_class_property(r,r),
rdfs_individual_of(r,r),
rdfs_label(r,-),
rdfs_label(r,?,-).
/*******************************
* PROPERTY HIERARCHY *
*******************************/
%! rdfs_subproperty_of(+SubProperty, ?Property) is nondet.
%! rdfs_subproperty_of(?SubProperty, +Property) is nondet.
%
% Query the property hierarchy.
rdfs_subproperty_of(SubProperty, Property) :-
rdf_reachable(SubProperty, rdfs:subPropertyOf, Property).
/*******************************
* CLASS HIERARCHY *
*******************************/
%! rdfs_subclass_of(+Class, ?Super) is nondet.
%! rdfs_subclass_of(?Class, +Super) is nondet.
%
% Generate sub/super classes. rdf_reachable/3 considers the
% rdfs:subPropertyOf relation as well as cycles. Note that by
% definition all classes are subclass of rdfs:Resource, a case
% which is dealt with by the 1st and 3th clauses :-(
%
% According to production 2.4 "rdfs:Datatype", Each instance of
% rdfs:Datatype is a subclass of rdfs:Literal.
rdfs_subclass_of(Class, Super) :-
rdf_equal(rdfs:'Resource', Resource),
Super == Resource,
!,
rdfs_individual_of(Class, rdfs:'Class').
rdfs_subclass_of(Class, Super) :-
rdf_reachable(Class, rdfs:subClassOf, Super).
rdfs_subclass_of(Class, Super) :-
nonvar(Class),
var(Super),
\+ rdf_reachable(Class, rdfs:subClassOf, rdfs:'Resource'),
rdfs_individual_of(Class, rdfs:'Class'),
rdf_equal(Super, rdfs:'Resource').
rdfs_subclass_of(Class, Super) :- % production 2.4
( nonvar(Class)
-> rdf_has(Class, rdf:type, CType),
rdf_reachable(CType, rdfs:subClassOf, rdfs:'Datatype'),
\+ rdf_reachable(Class, rdfs:subClassOf, rdfs:'Literal'),
rdf_equal(Super, rdfs:'Literal')
; nonvar(Super)
-> rdf_reachable(Super, rdfs:subClassOf, rdfs:'Literal'),
rdfs_individual_of(Class, rdfs:'Datatype')
).
/*******************************
* INDIVIDUALS *
*******************************/
%! rdfs_individual_of(+Resource, +Class) is semidet.
%! rdfs_individual_of(+Resource, -Class) is nondet.
%! rdfs_individual_of(-Resource, +Class) is nondet.
%
% Generate resources belonging to a class or classes a resource
% belongs to. We assume everything at the `object' end of a triple
% is a class. A validator should confirm this property.
%
% rdfs_individual_of(+, -) does not exploit domain and range
% properties, deriving that if rdf(R, P, _) is present R must
% satisfy the domain of P (and similar for range).
%
% There are a few hacks:
%
% * Any resource is an individual of rdfs:Resource
% * literal(_) is an individual of rdfs:Literal
rdfs_individual_of(Resource, Class) :-
nonvar(Resource),
!,
( nonvar(Class)
-> ( rdf_equal(Class, rdfs:'Resource')
-> true
; rdfs_individual_of_r_c(Resource, Class)
-> true
)
; rdfs_individual_of_r_c(Resource, Class)
).
rdfs_individual_of(Resource, Class) :-
nonvar(Class),
!,
( rdf_equal(Class, rdfs:'Resource')
-> rdf_subject(Resource)
; rdfs_subclass_of(SubClass, Class),
rdf_has(Resource, rdf:type, SubClass)
).
rdfs_individual_of(_Resource, _Class) :-
throw(error(instantiation_error, _)).
%! rdfs_individual_of_r_c(+Resource, ?Class) is nondet.
rdfs_individual_of_r_c(literal(_), Class) :-
!,
rdfs_subclass_of(Class, rdfs:'Literal').
rdfs_individual_of_r_c(Resource, Class) :-
( rdf_has(Resource, rdf:type, MyClass)
*-> rdfs_subclass_of(MyClass, Class)
; rdf_equal(Class, rdfs:'Resource')
).
%! rdfs_label(+Resource, -Label).
%! rdfs_label(-Resource, +Label).
%
% Convert between class and label. If the label is generated from
% the resource the it uses both rdfs:label and its sub-properties,
% but labels registered with rdfs:label are returned first.
rdfs_label(Resource, Label) :-
rdfs_label(Resource, _, Label).
%! rdfs_label(+Resource, ?Lang, -Label) is multi.
%! rdfs_label(+Resource, ?Lang, +Label) is semidet.
%! rdfs_label(-Resource, ?Lang, ?Label) is nondet.
%
% Resource has Label in Lang. If Resource is nonvar calls
% take_label/3 which is guaranteed to succeed label.
rdfs_label(Resource, Lang, Label) :-
nonvar(Resource),
!,
take_label(Resource, Lang, Label).
rdfs_label(Resource, Lang, Label) :-
rdf_has(Resource, rdfs:label, literal(lang(Lang, Label))).
%! rdfs_ns_label(+Resource, -Label) is multi.
%! rdfs_ns_label(+Resource, ?Lang, -Label) is multi.
%
% Present label with namespace indication. This predicate is
% intended to provide meaningful short names applicable to
% ontology maintainers. Note that this predicate is non-deterministic
% if the resource has multiple rdfs:label properties
rdfs_ns_label(Resource, Label) :-
rdfs_ns_label(Resource, _, Label).
rdfs_ns_label(Resource, Lang, Label) :-
rdfs_label(Resource, Lang, Label0),
( rdf_global_id(NS:_, Resource),
Label0 \== ''
-> atomic_list_concat([NS, Label0], :, Label)
; \+ rdf_has(Resource, rdfs:label, _)
-> Label = Resource
; member(Sep, [#,/]),
sub_atom(Resource, B, L, A, Sep),
sub_atom(Resource, _, A, 0, Frag),
\+ sub_atom(Frag, _, _, _, Sep)
-> Len is B+L,
sub_atom(Resource, 0, Len, _, NS),
atomic_list_concat([NS, Label0], :, Label)
; Label = Label0
).
%! take_label(+Resource, ?Lang, -Label) is multi.
%
% Get the label to use for a resource in the give Language. First
% tries label_of/3. If this fails, break the Resource over # or /
% and if all fails, unify Label with Resource.
take_label(Resource, Lang, Label) :-
( label_of(Resource, Lang, Label)
*-> true
; after_char(Resource, '#', Local)
-> Label = Local
; after_char(Resource, '/', Local)
-> Label = Local
; Label = Resource
).
after_char(Atom, Char, Rest) :-
State = last(-),
( sub_atom(Atom, _, _, L, Char),
nb_setarg(1, State, L),
fail
; arg(1, State, L),
L \== (-)
),
sub_atom(Atom, _, L, 0, Rest).
%! label_of(+Resource, ?Lang, ?Label) is nondet.
%
% True if rdf_has(Resource, rdfs:label, literal(Lang, Label)) is
% true, but guaranteed to generate rdfs:label before any
% subproperty thereof.
label_of(Resource, Lang, Label) :-
rdf(Resource, rdfs:label, literal(lang(Lang, Label))),
nonvar(Lang).
label_of(Resource, Lang, Label) :-
rdf_equal(rdfs:label, LabelP),
rdf_has(Resource, LabelP, literal(lang(Lang, Label)), P),
nonvar(Lang),
P \== LabelP.
label_of(Resource, Lang, Label) :-
var(Lang),
rdf_has(Resource, rdfs:label, literal(type(xsd:string, Label))).
%! rdfs_class_property(+Class, ?Property)
%
% Enumerate the properties in the domain of Class.
rdfs_class_property(Class, Property) :-
rdfs_individual_of(Property, rdf:'Property'),
rdf_has(Property, rdfs:domain, Domain),
rdfs_subclass_of(Class, Domain).
/*******************************
* COLLECTIONS *
*******************************/
%! rdfs_member(?Element, +Set)
%
% As Prolog member on sets. Operates both on attributes parsed as
% parseType="Collection" as well as on Bag, Set and Alt.
rdfs_member(Element, Set) :-
rdf_has(Set, rdf:first, _),
!,
rdfs_collection_member(Element, Set).
rdfs_member(Element, Set) :-
container_class(Class),
rdfs_individual_of(Set, Class),
!,
( nonvar(Element)
-> rdf(Set, Predicate, Element),
rdf_member_property(Predicate, _N)
; findall(N-V, rdf_nth(Set, N, V), Pairs),
keysort(Pairs, Sorted),
member(_-Element, Sorted)
).
rdf_nth(Set, N, V) :-
rdf(Set, P, V),
rdf_member_property(P, N).
:- rdf_meta container_class(r).
container_class(rdf:'Bag').
container_class(rdf:'Seq').
container_class(rdf:'Alt').
rdfs_collection_member(Element, Set) :-
rdf_has(Set, rdf:first, Element).
rdfs_collection_member(Element, Set) :-
rdf_has(Set, rdf:rest, Tail),
!,
rdfs_collection_member(Element, Tail).
%! rdfs_list_to_prolog_list(+RDFSList, -PrologList)
%
% Convert ann RDFS list (result from parseType=Collection) into a
% Prolog list of elements.
rdfs_list_to_prolog_list(Set, []) :-
rdf_equal(Set, rdf:nil),
!.
rdfs_list_to_prolog_list(Set, [H|T]) :-
rdf_has(Set, rdf:first, H),
rdf_has(Set, rdf:rest, Tail),
!,
rdfs_list_to_prolog_list(Tail, T).
%! rdfs_assert_list(+Resources, -List) is det.
%! rdfs_assert_list(+Resources, -List, +DB) is det.
%
% Create an RDF list from the given Resources.
rdfs_assert_list(Resources, List) :-
rdfs_assert_list(Resources, List, user).
rdfs_assert_list([], Nil, _) :-
rdf_equal(rdf:nil, Nil).
rdfs_assert_list([H|T], List, DB) :-
rdfs_assert_list(T, Tail, DB),
rdf_bnode(List),
rdf_assert(List, rdf:rest, Tail, DB),
rdf_assert(List, rdf:first, H, DB),
rdf_assert(List, rdf:type, rdf:'List', DB).
/*******************************
* SEARCH IN HIERARCHY *
*******************************/
%! rdfs_find(+String, +Domain, ?Properties, +Method, -Subject)
%
% Search all classes below Domain for a literal property with
% that matches String. Method is one of
%
% * substring
% * word
% * prefix
% * exact
%
% domain is defined by owl_satisfy from owl.pl
%
% Note that the rdfs:label field is handled by rdfs_label/2,
% making the URI-ref fragment name the last resort to determine
% the label.
rdfs_find(String, Domain, Fields, Method, Subject) :-
var(Fields),
!,
For =.. [Method,String],
rdf_has(Subject, Field, literal(For, _)),
owl_satisfies(Domain, Subject),
Fields = [Field]. % report where we found it.
rdfs_find(String, Domain, Fields, Method, Subject) :-
globalise_list(Fields, GlobalFields),
For =.. [Method,String],
member(Field, GlobalFields),
( Field == resource
-> rdf_subject(Subject),
rdf_match_label(Method, String, Subject)
; rdf_has(Subject, Field, literal(For, _))
),
owl_satisfies(Domain, Subject).
owl_satisfies(Domain, _) :-
rdf_equal(rdfs:'Resource', Domain),
!.
% Descriptions
owl_satisfies(class(Domain), Resource) :-
!,
( rdf_equal(Domain, rdfs:'Resource')
-> true
; rdfs_subclass_of(Resource, Domain)
).
owl_satisfies(union_of(Domains), Resource) :-
!,
member(Domain, Domains),
owl_satisfies(Domain, Resource),
!.
owl_satisfies(intersection_of(Domains), Resource) :-
!,
in_all_domains(Domains, Resource).
owl_satisfies(complement_of(Domain), Resource) :-
!,
\+ owl_satisfies(Domain, Resource).
owl_satisfies(one_of(List), Resource) :-
!,
memberchk(Resource, List).
% Restrictions
owl_satisfies(all_values_from(Domain), Resource) :-
( rdf_equal(Domain, rdfs:'Resource')
-> true
; rdfs_individual_of(Resource, Domain)
),
!.
owl_satisfies(some_values_from(_Domain), _Resource) :- !.
owl_satisfies(has_value(Value), Resource) :-
rdf_equal(Value, Resource).
in_all_domains([], _).
in_all_domains([H|T], Resource) :-
owl_satisfies(H, Resource),
in_all_domains(T, Resource).
globalise_list([], []) :- !.
globalise_list([H0|T0], [H|T]) :-
!,
globalise_list(H0, H),
globalise_list(T0, T).
globalise_list(X, G) :-
rdf_global_id(X, G).