NAME

       Attean::SimpleQueryEvaluator - Simple query evaluator

VERSION

       This document describes Attean::SimpleQueryEvaluator version 0.033

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 {}".

       "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 )".

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.

perl v5.36.0                                       2022-10-06                  Attean::SimpleQueryEvaluator(3pm)