NAME

       RDF::Query::Algebra::Optional - Algebra class for Optional patterns

VERSION

       This document describes RDF::Query::Algebra::Optional version 2.910.

METHODS

       Beyond the methods documented below, this class inherits methods from the
       RDF::Query::Algebra class.

       "new ( $pattern, $opt_pattern )"
           Returns a new Optional structure.

       "construct_args"
           Returns a list of arguments that, passed to this class' constructor, will produce a
           clone of this algebra pattern.

       "pattern"
           Returns the base pattern (LHS) onto which the optional pattern joins.

       "optional"
           Returns the optional pattern (RHS).

       "sse"
           Returns the SSE string for this algebra expression.

       "as_sparql"
           Returns the SPARQL string for this algebra expression.

       "as_spin ( $model )"
           Adds statements to the given model to represent this algebra object in the SPARQL
           Inferencing Notation (<http://www.spinrdf.org/>).

       "as_hash"
           Returns the query as a nested set of plain data structures (no objects).

       "type"
           Returns the type of this algebra expression.

       "referenced_variables"
           Returns a list of the variable names used in this algebra expression.

       "potentially_bound"
           Returns a list of the variable names used in this algebra expression that will bind
           values during execution.

       "definite_variables"
           Returns a list of the variable names that will be bound after evaluating this algebra
           expression.

AUTHOR

        Gregory Todd Williams <gwilliams@cpan.org>