com.bigdata.rdf.sparql.ast.eval

Class ASTConstructIterator

java.lang.Object

com.bigdata.rdf.sparql.ast.eval.ASTConstructIterator

All Implemented Interfaces:

info.aduna.iteration.CloseableIteration<BigdataStatement,org.openrdf.query.QueryEvaluationException>, info.aduna.iteration.Iteration<BigdataStatement,org.openrdf.query.QueryEvaluationException>

public class ASTConstructIterator
extends Object
implements info.aduna.iteration.CloseableIteration<BigdataStatement,org.openrdf.query.QueryEvaluationException>

Iterator consumes the solutions from a query and interprets them according to a ConstructNode. Ground triples in the template are output immediately. Any non-ground triples are output iff they are fully (and validly) bound for a given solution. Blank nodes are scoped to a solution.

Note: This supports construct of quads, but the SPARQL grammar does not.

Version:

$Id: ASTConstructIterator.java 5131 2011-09-05 20:48:48Z thompsonbry $

Author:

Bryan Thompson

Field Summary

Fields

Modifier and Type	Field and Description
static boolean	flagToCheckNativeDistinctQuadsInvocationForJUnitTesting

Constructor Summary

Constructors

Constructor and Description
ASTConstructIterator(AST2BOpContext context, AbstractTripleStore tripleStore, ConstructNode construct, GraphPatternGroup<?> whereClause, Map<String,BigdataBNode> bnodesIn, info.aduna.iteration.CloseableIteration<org.openrdf.query.BindingSet,org.openrdf.query.QueryEvaluationException> src)

Method Summary

Methods

Modifier and Type	Method and Description
void	close()
boolean	hasNext()
BigdataStatement	next()
void	remove()

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

flagToCheckNativeDistinctQuadsInvocationForJUnitTesting

public static boolean flagToCheckNativeDistinctQuadsInvocationForJUnitTesting

Constructor Detail

ASTConstructIterator

public ASTConstructIterator(AST2BOpContext context,
                    AbstractTripleStore tripleStore,
                    ConstructNode construct,
                    GraphPatternGroup<?> whereClause,
                    Map<String,BigdataBNode> bnodesIn,
                    info.aduna.iteration.CloseableIteration<org.openrdf.query.BindingSet,org.openrdf.query.QueryEvaluationException> src)

Parameters:

tripleStore -

construct - The ConstructNode

whereClause - The WHERE clause (used to identify construct templates which obviously produce DISTINCT triples).

bnodes - A mapping from bnode IDs to BigdataBNodes that will be imposed (optional). This MUST be null when the top-level operation is a CONSTRUCT since the semantics of CONSTRUCT require that blank node ID assignments are scoped to the solution. However, when a DESCRIBE query is rewritten into a CONSTRUCT, the blank node identifier mappings must be scoped to the response graph. For a DESCRIBE that uses a recursive expansion (CBD, etc.), the blank node IDs must be scoped to the entire response, not just the individual DESCRIBE queries that are issued in support of the top-level DESCRIBE request.

src - The solutions that will be used to construct the triples.

Method Detail

hasNext

public boolean hasNext()
                throws org.openrdf.query.QueryEvaluationException

Specified by:

hasNext in interface info.aduna.iteration.Iteration<BigdataStatement,org.openrdf.query.QueryEvaluationException>

Throws:

org.openrdf.query.QueryEvaluationException

next

public BigdataStatement next()
                      throws org.openrdf.query.QueryEvaluationException

Specified by:

next in interface info.aduna.iteration.Iteration<BigdataStatement,org.openrdf.query.QueryEvaluationException>

Throws:

org.openrdf.query.QueryEvaluationException

close

public void close()
           throws org.openrdf.query.QueryEvaluationException

Specified by:

close in interface info.aduna.iteration.CloseableIteration<BigdataStatement,org.openrdf.query.QueryEvaluationException>

Throws:

org.openrdf.query.QueryEvaluationException

remove

public void remove()
            throws org.openrdf.query.QueryEvaluationException

Specified by:

remove in interface info.aduna.iteration.Iteration<BigdataStatement,org.openrdf.query.QueryEvaluationException>

Throws:

org.openrdf.query.QueryEvaluationException