Attean::SimpleQueryEvaluator - Simple query evaluator
This document describes Attean::SimpleQueryEvaluator version 0.033
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 {}
request_signer
If set, used to modify HTTP::Request objects used in evaluating SERVICE calls before the request is made. This may be used to, for example, add cryptographic signature headers to the request. The modification is performed by calling $request_signer->sign( $request ).
$request_signer->sign( $request )
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.