Java Code Examples for org.eclipse.rdf4j.query.algebra.Var#isAnonymous()

private void appendVar(StringBuilder builder, Var var) {
	if (var.hasValue() && var.isAnonymous()) {
		Value value = var.getValue();
		writeValue(builder, value);
	} else {
		String varName = var.getName();
		appendVar(builder, varName);
	}
	builder.append(" ");
}
 

private void appendFilter(StringBuilder builder, Var var) {
	if (var.hasValue() && !var.isAnonymous()) {
		builder.append("\nFILTER sameTerm(");
		appendVar(builder, var.getName());
		builder.append(", ");
		writeValue(builder, var.getValue());
		builder.append(")");
	}
}
 

/**
 * @inheritDoc
 */
@Override
public void meet(Var theVar) throws Exception {
	if (theVar.isAnonymous() && !theVar.hasValue()) {
		mBuffer.append("?").append(BaseTupleExprRenderer.scrubVarName(theVar.getName()));
	} else if (theVar.hasValue()) {
		mBuffer.append(RenderUtils.getSPARQLQueryString(theVar.getValue()));
	} else {
		mBuffer.append("?").append(theVar.getName());
	}
}
 

/**
 * @inheritDoc
 */
@Override
public void meet(Var theVar) throws Exception {
	if (theVar.isAnonymous() && !theVar.hasValue()) {
		mBuffer.append(BaseTupleExprRenderer.scrubVarName(theVar.getName().substring(1)));
	} else if (theVar.hasValue()) {
		mBuffer.append(RenderUtils.getSerqlQueryString(theVar.getValue()));
	} else {
		mBuffer.append(theVar.getName());
	}
}
 

@Override
public Modify visit(ASTDeleteWhere node, Object data) throws VisitorException {
	// Collect delete clause triples
	GraphPattern parentGP = graphPattern;
	graphPattern = new GraphPattern();

	// inherit scope & context
	graphPattern.setStatementPatternScope(parentGP.getStatementPatternScope());
	graphPattern.setContextVar(parentGP.getContextVar());

	for (int i = 0; i < node.jjtGetNumChildren(); i++) {
		node.jjtGetChild(i).jjtAccept(this, data);
	}

	where = graphPattern.buildTupleExpr();
	graphPattern = parentGP;

	TupleExpr deleteExpr = where.clone();

	// FIXME we should adapt the grammar so we can avoid doing this
	// post-processing.
	VarCollector collector = new VarCollector();
	deleteExpr.visit(collector);
	for (Var var : collector.getCollectedVars()) {
		if (var.isAnonymous() && !var.hasValue()) {
			throw new VisitorException("DELETE WHERE may not contain blank nodes");
		}
	}

	Modify modify = new Modify(deleteExpr, null, where);

	return modify;
}
 

@Override
public TupleExpr visit(ASTDeleteClause node, Object data) throws VisitorException {
	TupleExpr result = (TupleExpr) data;

	// Collect construct triples
	GraphPattern parentGP = graphPattern;

	graphPattern = new GraphPattern();

	// inherit scope & context
	graphPattern.setStatementPatternScope(parentGP.getStatementPatternScope());
	graphPattern.setContextVar(parentGP.getContextVar());

	for (int i = 0; i < node.jjtGetNumChildren(); i++) {
		node.jjtGetChild(i).jjtAccept(this, data);
	}

	TupleExpr deleteExpr = graphPattern.buildTupleExpr();
	Map<String, Object> tripleVars = TripleRefCollector.process(where);

	// FIXME we should adapt the grammar so we can avoid doing this in
	// post-processing.
	VarCollector collector = new VarCollector();
	deleteExpr.visit(collector);
	for (Var var : collector.getCollectedVars()) {
		// skip vars that are provided by ValueExprTripleRef - added as Extentsion
		if (tripleVars.containsKey(var.getName())) {
			continue;
		}
		if (var.isAnonymous() && !var.hasValue()) {
			// blank node in delete pattern, not allowed by SPARQL spec.
			throw new VisitorException("DELETE clause may not contain blank nodes");
		}
	}

	graphPattern = parentGP;

	return deleteExpr;

}
 

/**
 * @inheritDoc
 */
@Override
public void meet(Var theVar)
        throws Exception
{
    if (theVar.isAnonymous() && !theVar.hasValue()) {
        mBuffer.append("?").append(BaseTupleExprRenderer.scrubVarName(theVar.getName()));
    }
    else if (theVar.hasValue()) {
        mBuffer.append(SPARQLQueryStringUtil.toSPARQL(theVar.getValue()));
    }
    else {
        mBuffer.append("?").append(theVar.getName());
    }
}
 

@Override
public void meet(StatementPattern node) throws RepositoryException {
	StringBuilder builder = new StringBuilder();
	Scope scope = node.getScope();
	Var subj = node.getSubjectVar();
	Var pred = node.getPredicateVar();
	Var obj = node.getObjectVar();
	Var ctx = node.getContextVar();
	boolean cokay = ctx == null && scope.equals(Scope.DEFAULT_CONTEXTS)
			|| ctx != null && scope.equals(Scope.NAMED_CONTEXTS);
	boolean sokay = !subj.hasValue() || subj.isAnonymous() || subj.getValue() instanceof IRI;
	boolean ookay = !obj.hasValue() || obj.isAnonymous() || obj.getValue() instanceof IRI
			|| obj.getValue() instanceof Literal;
	if (cokay && sokay && ookay) {
		variables.clear();
		if (ctx != null) {
			builder.append("GRAPH ");
			appendVar(builder, ctx.getName());
			builder.append(" {\n");
		}
		appendVar(builder, subj);
		appendVar(builder, pred);
		appendVar(builder, obj);
		builder.append(" .");
		appendFilter(builder, subj);
		appendFilter(builder, pred);
		appendFilter(builder, obj);
		if (ctx != null) {
			if (ctx.hasValue()) {
				builder.append("\nFILTER sameTerm(");
				appendVar(builder, ctx.getName());
				builder.append(", ");
				writeValue(builder, ctx.getValue());
				builder.append(")\n");
			}
			builder.append("}");
		}
		this.pattern = builder.toString();
		this.patternNode = node;
	} else {
		this.patternNode = null; // NOPMD
	}
}
 

@Override
public void meet(Var var) {
	if (!var.isAnonymous()) {
		varNames.add(var.getName());
	}
}
 

@Override
public Object visit(ASTBind node, Object data) throws VisitorException {
	// bind expression
	Object child0 = node.jjtGetChild(0).jjtAccept(this, data);
	ValueExpr ve = child0 instanceof ValueExpr ? (ValueExpr) child0
			: (child0 instanceof TripleRef) ? ((TripleRef) child0).getExprVar() : null;
	if (ve == null) {
		throw new IllegalArgumentException("Unexpected expressin on bind");
	}

	// name to bind the expression outcome to
	Node aliasNode = node.jjtGetChild(1);
	String alias = ((ASTVar) aliasNode).getName();

	Extension extension = new Extension();
	extension.addElement(new ExtensionElem(ve, alias));

	TupleExpr result = null;
	TupleExpr arg = graphPattern.buildTupleExpr();

	// check if alias is not previously used.
	if (arg.getBindingNames().contains(alias)) {
		// SES-2314 we need to doublecheck that the reused varname is not
		// just
		// for an anonymous var or a constant.
		VarCollector collector = new VarCollector();
		arg.visit(collector);
		for (Var v : collector.getCollectedVars()) {
			if (alias.equals(v.getName())) {
				if (!v.isConstant() && !v.isAnonymous()) {
					throw new VisitorException(String.format("BIND clause alias '%s' was previously used", alias));
				}
				break;
			}
		}
	}

	if (arg instanceof Filter) {
		result = arg;
		// we need to push down the extension so that filters can operate on
		// the BIND expression.
		while (((Filter) arg).getArg() instanceof Filter) {
			arg = ((Filter) arg).getArg();
		}

		extension.setArg(((Filter) arg).getArg());
		((Filter) arg).setArg(extension);
	} else {
		extension.setArg(arg);
		result = extension;
	}

	GraphPattern replacementGP = new GraphPattern(graphPattern);
	replacementGP.addRequiredTE(result);

	graphPattern = replacementGP;

	return result;
}