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AtteanX-Store-MemoryTripleStore-0.000_02
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AtteanX::Store::MemoryTripleStore - In-memory RDF triple store

AtteanX::Store::MemoryTripleStore provides an in-memory triple-store that is especially optimized for matching BGPs which contain at least one bound subject or object (e.g. preferring star or path queries).

The triple store is read-only, requiring a filename to be specified during construction which points at an N-Triples or Turtle file containing the RDF data to load. The triple store links with libraptor2 to allow fast parsing of input RDF files.

Format Restrictions

There are several restrictions on the RDF data that is allowed by the system:

Perl Example

In addition to being a fully-functioning Attean store, this code may be used in a more direct fashion via the AtteanX::Store::MemoryTripleStore::Query class to iteratively construct queries over the loaded RDF data:

% perl Makefile.PL && make install
% cat test.pl
use v5.14;
use Attean::RDF;
my $store	= Attean->get_store('MemoryTripleStore')->new(filename => 'dbpedia.nt');
my $model	= Attean::TripleModel->new( stores => { 'http://example.org/' => $store } );
my $query	= AtteanX::Store::MemoryTripleStore::Query->new(store => $store);
my $t1		= Attean::TriplePattern->new(variable('s'), iri('http://dbpedia.org/ontology/longName'), variable('name'));
my $t2		= Attean::TriplePattern->new(variable('s'), iri('http://www.w3.org/2003/01/geo/wgs84_pos#lat'), variable('lat'));
my $t3		= Attean::TriplePattern->new(variable('s'), iri('http://www.w3.org/2003/01/geo/wgs84_pos#long'), variable('long'));
$query->add_bgp($t1, $t2, $t3);
$query->add_filter('name', 'regex', 'Island', 'i');
$query->add_sort(qw(name));
$query->add_project(qw(name));
my $iter	= $query->evaluate($model);
while (my $result = $iter->next) {
	say $result->as_string;
}

% perl test.pl
{name="Ascension Island"@en, lat="-7.933333333333334"^^<http://www.w3.org/2001/XMLSchema#float>, long="-14.416666666666666"^^<http://www.w3.org/2001/XMLSchema#float>}
{name="Bouvet Island"@en, lat="-54.43"^^<http://www.w3.org/2001/XMLSchema#float>, long="3.38"^^<http://www.w3.org/2001/XMLSchema#float>}
{name="Cayman Islands"@en, lat="19.333333333333332"^^<http://www.w3.org/2001/XMLSchema#float>, long="-81.4"^^<http://www.w3.org/2001/XMLSchema#float>}
{name="Commander Islands"@en, lat="55.2"^^<http://www.w3.org/2001/XMLSchema#float>, long="165.98333333333332"^^<http://www.w3.org/2001/XMLSchema#float>}
{name="Commonwealth of the Northern Mariana Islands"@en, lat="15.233333333333333"^^<http://www.w3.org/2001/XMLSchema#float>, long="145.75"^^<http://www.w3.org/2001/XMLSchema#float>}
{name="Cook Islands"@en, lat="-21.2"^^<http://www.w3.org/2001/XMLSchema#float>, long="-159.76666666666668"^^<http://www.w3.org/2001/XMLSchema#float>}
{name="Falkland Islands"@en, lat="-51.7"^^<http://www.w3.org/2001/XMLSchema#float>, long="-57.85"^^<http://www.w3.org/2001/XMLSchema#float>}
{name="Faroe Islands"@en, lat="62.0"^^<http://www.w3.org/2001/XMLSchema#float>, long="-6.783333333333333"^^<http://www.w3.org/2001/XMLSchema#float>}
...

Command Line Example

The package also contains a Makefile for building a command-line tool that may be used to query loaded RDF data directly, without using the perl API:

% make -f Makefile.cli
% ./ts dbpedia.nt
ts> begin
ts> bgp ?s <http://dbpedia.org/ontology/longName> ?name ?s <http://www.w3.org/2003/01/geo/wgs84_pos#lat> ?lat ?s <http://www.w3.org/2003/01/geo/wgs84_pos#long> ?long
ts> filter regex ?name island i
ts> project name lat long
ts> sort name
ts> end
name="Ascension Island"@en lat=-7.933333333333334 long=-14.416666666666666 
name="Bouvet Island"@en lat=-54.43 long=3.38 
name="Cayman Islands"@en lat=19.333333333333332 long=-81.4 
name="Commander Islands"@en lat=55.2 long=165.98333333333332 
name="Commonwealth of the Northern Mariana Islands"@en lat=15.233333333333333 long=145.75 
name="Cook Islands"@en lat=-21.2 long=-159.76666666666668 
name="Falkland Islands"@en lat=-51.7 long=-57.85 
name="Faroe Islands"@en lat=62.0 long=-6.783333333333333 
...