Attean::SimpleQueryEvaluator - Simple query evaluator
This document describes Attean::SimpleQueryEvaluator version 0.032
use v5.14; use Attean; my $algebra = Attean->get_parser('SPARQL')->parse('SELECT * WHERE { ... }'); my $active_graph = Attean::IRI->new('http://example.org/'); my $e = Attean::SimpleQueryEvaluator->new( model => $model ); my $iter = $e->evaluate( $algebra, $active_graph );
The Attean::SimpleQueryEvaluator class implements a simple query evaluator that, given an Attean::API::Algebra and a Attean::API::Model object, evaluates the query represented by the algebra using data from the model, and returns a query result.
model
The Attean::API::Model object used for query evaluation.
default_graph
The Attean::API::IRI object representing the default graph in the model. The default graph will be excluded from enumeration of graph names for query features such as GRAPH ?g {}.
GRAPH ?g {}
evaluate( $algebra, $active_graph )
Returns an Attean::API::Iterator object with results produced by evaluating the query $algebra against the evaluator's model, using the supplied $active_graph.
$algebra
$active_graph
evaluate_pattern( $pattern, $active_graph, \@new_vars, \%blanks )
Returns an Attean::API::Iterator object with results produced by evaluating the triple- or quad-pattern $pattern against the evaluator's model, using the supplied $active_graph.
$pattern
If the ground_blanks option is false, replaces blank nodes in the pattern with fresh variables before evaluation, and populates %blanks with pairs ($variable_name => $variable_node). Each new variable is also appended to @new_vars as it is created.
ground_blanks
%blanks
@new_vars
Please report any bugs or feature requests to through the GitHub web interface at https://github.com/kasei/attean/issues.
Gregory Todd Williams <gwilliams@cpan.org>
<gwilliams@cpan.org>
Copyright (c) 2014--2022 Gregory Todd Williams. This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.
To install Attean, copy and paste the appropriate command in to your terminal.
cpanm
cpanm Attean
CPAN shell
perl -MCPAN -e shell install Attean
For more information on module installation, please visit the detailed CPAN module installation guide.