/usr/share/perl5/RDF/Query/Algebra/NamedGraph.pm is in librdf-query-perl 2.918-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 | # RDF::Query::Algebra::NamedGraph
# -----------------------------------------------------------------------------
=head1 NAME
RDF::Query::Algebra::NamedGraph - Algebra class for NamedGraph patterns
=head1 VERSION
This document describes RDF::Query::Algebra::NamedGraph version 2.918.
=cut
package RDF::Query::Algebra::NamedGraph;
use strict;
use warnings;
no warnings 'redefine';
use base qw(RDF::Query::Algebra);
use Data::Dumper;
use Log::Log4perl;
use RDF::Query::Error;
use Carp qw(carp croak confess);
use Scalar::Util qw(blessed reftype);
use RDF::Trine::Iterator qw(sgrep smap swatch);
######################################################################
our ($VERSION);
BEGIN {
$VERSION = '2.918';
}
######################################################################
=head1 METHODS
Beyond the methods documented below, this class inherits methods from the
L<RDF::Query::Algebra> class.
=over 4
=cut
=item C<new ( $graph, $pattern )>
Returns a new NamedGraph structure.
=cut
sub new {
my $class = shift;
my $graph = shift;
my $pattern = shift;
return bless( [ 'GRAPH', $graph, $pattern ], $class );
}
=item C<< construct_args >>
Returns a list of arguments that, passed to this class' constructor,
will produce a clone of this algebra pattern.
=cut
sub construct_args {
my $self = shift;
return ($self->graph, $self->pattern);
}
=item C<< graph >>
Returns the graph node of the named graph expression.
=cut
sub graph {
my $self = shift;
if (@_) {
my $graph = shift;
$self->[1] = $graph;
}
my $graph = $self->[1];
return $graph;
}
=item C<< pattern >>
Returns the graph pattern of the named graph expression.
=cut
sub pattern {
my $self = shift;
return $self->[2];
}
=item C<< quads >>
Returns a list of the quads belonging to this NamedGraph.
=cut
sub quads {
my $self = shift;
my @quads;
foreach my $p ($self->subpatterns_of_type('RDF::Query::Algebra::BasicGraphPattern')) {
push(@quads, $p->quads);
}
my @graphquads;
foreach my $q (@quads) {
my $st = RDF::Trine::Statement::Quad->new(
$q->subject,
$q->predicate,
$q->object,
$self->graph,
);
push(@graphquads, $st);
}
return @graphquads;
}
=item C<< sse >>
Returns the SSE string for this algebra expression.
=cut
sub sse {
my $self = shift;
my $context = shift;
my $prefix = shift || '';
my $indent = $context->{indent} || '';
return sprintf(
"(namedgraph\n${prefix}${indent}%s\n${prefix}${indent}%s)",
$self->graph->sse( $context, "${prefix}${indent}" ),
$self->pattern->sse( $context, "${prefix}${indent}" )
);
}
=item C<< explain >>
Returns a string serialization of the algebra appropriate for display on the
command line.
=cut
sub explain {
my $self = shift;
my $s = shift;
my $count = shift;
my $indent = $s x $count;
my $string = "${indent}named graph pattern\n"
. "${indent}${s}graph: " . $self->graph->as_string . "\n"
. $self->pattern->explain( $s, $count+1 );
return $string;
}
=item C<< as_sparql >>
Returns the SPARQL string for this algebra expression.
=cut
sub as_sparql {
my $self = shift;
my $context = shift || {};
my $indent = shift;
my $pcontext = { %$context, force_ggp_braces => 1 };
my $string = sprintf(
"GRAPH %s %s",
$self->graph->as_sparql( $context, $indent ),
$self->pattern->as_sparql( $pcontext, $indent ),
);
return $string;
}
=item C<< as_hash >>
Returns the query as a nested set of plain data structures (no objects).
=cut
sub as_hash {
my $self = shift;
my $context = shift;
return {
type => lc($self->type),
graph => $self->graph,
pattern => $self->pattern->as_hash,
};
}
=item C<< as_spin ( $model ) >>
Adds statements to the given model to represent this algebra object in the
SPARQL Inferencing Notation (L<http://www.spinrdf.org/>).
=cut
sub as_spin {
my $self = shift;
my $model = shift;
my $spin = RDF::Trine::Namespace->new('http://spinrdf.org/spin#');
my $rdf = RDF::Trine::Namespace->new('http://www.w3.org/1999/02/22-rdf-syntax-ns#');
my @t = $self->pattern->as_spin( $model );
my $ng = RDF::Query::Node::Blank->new();
my $list = $model->add_list( @t );
$model->add_statement( RDF::Trine::Statement->new($ng, $rdf->type, $spin->NamedGraph) );
$model->add_statement( RDF::Trine::Statement->new($ng, $spin->elements, $list) );
return $ng;
}
=item C<< type >>
Returns the type of this algebra expression.
=cut
sub type {
return 'GRAPH';
}
=item C<< referenced_variables >>
Returns a list of the variable names used in this algebra expression.
=cut
sub referenced_variables {
my $self = shift;
my @list = RDF::Query::_uniq(
$self->pattern->referenced_variables,
(map { $_->name } grep { $_->isa('RDF::Query::Node::Variable') } ($self->graph)),
);
return @list;
}
=item C<< potentially_bound >>
Returns a list of the variable names used in this algebra expression that will
bind values during execution.
=cut
sub potentially_bound {
my $self = shift;
my @list = RDF::Query::_uniq(
$self->pattern->potentially_bound,
(map { $_->name } grep { $_->isa('RDF::Query::Node::Variable') } ($self->graph)),
);
return @list;
}
=item C<< definite_variables >>
Returns a list of the variable names that will be bound after evaluating this algebra expression.
=cut
sub definite_variables {
my $self = shift;
return RDF::Query::_uniq(
$self->pattern->definite_variables,
map { $_->name } grep { $_->isa('RDF::Query::Node::Variable') } ($self->graph),
);
}
=item C<< qualify_uris ( \%namespaces, $base_uri ) >>
Returns a new algebra pattern where all referenced Resource nodes representing
QNames (ns:local) are qualified using the supplied %namespaces.
=cut
sub qualify_uris {
my $self = shift;
my $class = ref($self);
my $ns = shift;
my $base_uri = shift;
my $pattern = $self->pattern->qualify_uris( $ns, $base_uri );
my $graph = $self->graph;
if (blessed($graph) and $graph->isa('RDF::Query::Node::Resource')) {
my $uri = $graph->uri;
if (ref($uri)) {
my ($n,$l) = @$uri;
unless (exists($ns->{ $n })) {
throw RDF::Query::Error::QuerySyntaxError -text => "Namespace $n is not defined";
}
my $resolved = join('', $ns->{ $n }, $l);
$graph = RDF::Query::Node::Resource->new( $resolved, $base_uri );
}
}
return $class->new( $graph, $pattern );
}
=item C<< check_duplicate_blanks >>
Returns true if blank nodes respect the SPARQL rule of no blank-label re-use
across BGPs, otherwise throws a RDF::Query::Error::QueryPatternError exception.
=cut
sub check_duplicate_blanks {
my $self = shift;
my @data;
foreach my $arg ($self->construct_args) {
if (blessed($arg) and $arg->isa('RDF::Query::Algebra')) {
push(@data, $arg->_referenced_blanks());
}
}
my %seen;
foreach my $d (@data) {
foreach my $b (@$d) {
if ($seen{ $b }++) {
throw RDF::Query::Error::QueryPatternError -text => "Same blank node identifier ($b) used in more than one BasicGraphPattern.";
}
}
}
return 1;
}
1;
__END__
=back
=head1 AUTHOR
Gregory Todd Williams <gwilliams@cpan.org>
=cut
|