# RDF::Query::Algebra::SubSelect
# -----------------------------------------------------------------------------
=head1 NAME
RDF::Query::Algebra::SubSelect - Algebra class for Subselects
=head1 VERSION
This document describes RDF::Query::Algebra::SubSelect version 2.913.
=cut
package RDF::Query::Algebra::SubSelect;
use strict;
use warnings;
use base qw(RDF::Query::Algebra);
use Log::Log4perl;
use URI::Escape;
use MIME::Base64;
use Data::Dumper;
use RDF::Query::Error;
use Carp qw(carp croak confess);
use Scalar::Util qw(blessed reftype);
use Storable qw(store_fd fd_retrieve);
use RDF::Trine::Iterator qw(sgrep smap swatch);
######################################################################
our ($VERSION, $BLOOM_FILTER_ERROR_RATE);
BEGIN {
$BLOOM_FILTER_ERROR_RATE = 0.1;
$VERSION = '2.913';
}
######################################################################
=head1 METHODS
Beyond the methods documented below, this class inherits methods from the
L<RDF::Query::Algebra> class.
=over 4
=cut
=item C<new ( $query )>
Returns a new SubSelect structure.
=cut
sub new {
my $class = shift;
my $query = shift;
return bless( [ $query ], $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->query);
}
=item C<< query >>
Returns the sub-select query.
=cut
sub query {
my $self = shift;
if (@_) {
my $query = shift;
$self->[0] = $query;
}
my $query = $self->[0];
return $query;
}
=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 $self->query->sse( $context );
}
=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 $string = sprintf(
"{ %s }",
$self->query->as_sparql( $context, $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),
pattern => $self->query->as_hash,
};
}
=item C<< type >>
Returns the type of this algebra expression.
=cut
sub type {
return 'SUBSELECT';
}
=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 = $self->query->pattern->referenced_variables;
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;
return $self->query->pattern->potentially_bound;
}
=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 $self->query->pattern->definite_variables;
}
1;
__END__
=back
=head1 AUTHOR
Gregory Todd Williams <gwilliams@cpan.org>
=cut