private Aggregate create(AggregateOperator operator)
		throws ValueExprEvaluationException, QueryEvaluationException {
	if (operator instanceof Count) {
		return new CountAggregate((Count) operator);
	} else if (operator instanceof Min) {
		return new MinAggregate((Min) operator);
	} else if (operator instanceof Max) {
		return new MaxAggregate((Max) operator);
	} else if (operator instanceof Sum) {
		return new SumAggregate((Sum) operator);
	} else if (operator instanceof Avg) {
		return new AvgAggregate((Avg) operator);
	} else if (operator instanceof Sample) {
		return new SampleAggregate((Sample) operator);
	} else if (operator instanceof GroupConcat) {
		return new ConcatAggregate((GroupConcat) operator);
	}
	return null;
}
 

@Override
public void meet(Count node) throws RDFHandlerException {
	handler.handleStatement(valueFactory.createStatement(subject, RDF.TYPE, SP.COUNT_CLASS));
	if (node.isDistinct()) {
		handler.handleStatement(
				valueFactory.createStatement(subject, SP.DISTINCT_PROPERTY, BooleanLiteral.TRUE));
	}
	Resource oldSubject = subject;
	super.meet(node);
	handler.handleStatement(valueFactory.createStatement(oldSubject, SP.EXPRESSION_PROPERTY, subject));
	subject = oldSubject;
}
 

public CountAggregate(Count operator) {
	super(operator);

	// for a wildcarded count with a DISTINCT clause we need to filter on
	// distinct bindingsets rather than individual values.
	if (operator.isDistinct() && getArg() == null) {
		distinctBindingSets = createSet("distinct-bs-" + this.hashCode());
	} else {
		distinctBindingSets = null;
	}
}
 

@Test
public void testCountNotZero() throws QueryEvaluationException {
	Group group = new Group(NONEMPTY_ASSIGNMENT);
	group.addGroupElement(new GroupElem("count", new Count(new Var("a"))));
	GroupIterator gi = new GroupIterator(evaluator, group, EmptyBindingSet.getInstance());

	assertThat(gi.next().getBinding("count").getValue()).isEqualTo(vf.createLiteral("9", XMLSchema.INTEGER));
}
 

@Override
public Object visit(ASTCount node, Object data) throws VisitorException {
	ValueExpr ve = null;
	if (node.jjtGetNumChildren() > 0) {
		ve = castToValueExpr(node.jjtGetChild(0).jjtAccept(this, data));
	}
	return new Count(ve, node.isDistinct());
}
 

/**
 * @inheritDoc
 */
@Override
public void meet(Count theOp)
        throws Exception
{
    unaryMeet("count", theOp);
}
 

@Override
public void meet(Count node) throws X {
	meetUnaryValueOperator(node);
}
 

/**
 * @inheritDoc
 */
@Override
public void meet(Count theOp) throws Exception {
	unaryMeet("count", theOp);
}
 

/**
 * @inheritDoc
 */
@Override
public void meet(Count theOp) throws Exception {
	unaryMeet("count", theOp);
}
 

@Override
public void meet(Count node) throws VisitorException {
	super.meet(node);
	meetAggregate(node);
}
 

@Override
public void meet(Count node) throws VisitorException {
	super.meet(node);
	meetAggregate(node);
}