table of contents
Attean::SimpleQueryEvaluator(3pm) | User Contributed Perl Documentation | Attean::SimpleQueryEvaluator(3pm) |
NAME¶
Attean::SimpleQueryEvaluator - Simple query evaluator
VERSION¶
This document describes Attean::SimpleQueryEvaluator version 0.032
SYNOPSIS¶
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 );
DESCRIPTION¶
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.
ATTRIBUTES¶
- "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 {}".
METHODS¶
- "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.
- "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 $active_graph.
If the "ground_blanks" option is false, replaces blank nodes in the pattern with fresh variables before evaluation, and populates %blanks with pairs ($variable_name => $variable_node). Each new variable is also appended to @new_vars as it is created.
BUGS¶
Please report any bugs or feature requests to through the GitHub web interface at <https://github.com/kasei/attean/issues>.
SEE ALSO¶
AUTHOR¶
Gregory Todd Williams "<gwilliams@cpan.org>"
COPYRIGHT¶
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.
2022-08-19 | perl v5.34.0 |