/*
* See http://www.w3.org/TR/rdf-sparql-query paragraph 11.4.7
*
* "(DATATYPE) Returns the datatype IRI of typedLit; returns xsd:string if the parameter is a simple literal."
*
* @see http://www.w3.org/TR/rdf-sparql-query
*/
private void convertDataType(E_Datatype expr) {
logger.debug("convertDataType " + expr.toString());
expr.getArg().visit(this);
Expression arg = expression.pop();
if (arg instanceof AttributeExprEx) {
AttributeExprEx variable = (AttributeExprEx) arg;
NodeMaker nm = variable.getNodeMaker();
DetermineNodeType filter = new DetermineNodeType();
nm.describeSelf(filter);
if (!filter.isLimittedToLiterals()) {
// type error, return false?
logger.warn("type error: " + variable + " is not a literal, returning FALSE");
expression.push(Expression.FALSE);
return;
}
RDFDatatype datatype = filter.getDatatype();
logger.debug("datatype " + datatype);
Node node =
Node.createURI((datatype != null) ? datatype.getURI() : XSDDatatype.XSDstring.getURI());
ConstantEx constantEx = new ConstantEx(NodeValue.makeNode(node).asString(), node);
logger.debug("pushing " + constantEx);
expression.push(constantEx);
} else if (arg instanceof ConstantEx) {
ConstantEx constant = (ConstantEx) arg;
Node node = constant.getNode();
if (!node.isLiteral()) {
// type error, return false?
logger.warn("type error: " + node + " is not a literal, returning FALSE");
expression.push(Expression.FALSE);
return;
}
RDFDatatype datatype = node.getLiteralDatatype();
logger.debug("datatype " + datatype);
node =
Node.createURI((datatype != null) ? datatype.getURI() : XSDDatatype.XSDstring.getURI());
ConstantEx constantEx = new ConstantEx(NodeValue.makeNode(node).asString(), node);
logger.debug("pushing " + constantEx);
expression.push(constantEx);
} else {
conversionFailed(expr);
}
}
/*
* See http://www.w3.org/TR/rdf-sparql-query paragraph 11.4.6
*
* "(LANG) Returns the language tag of ltrl, if it has one. It returns "" if ltrl has no language tag."
* @see http://www.w3.org/TR/rdf-sparql-query
*/
private void convertLang(E_Lang expr) {
logger.debug("convertLang " + expr.toString());
expr.getArg().visit(this);
Expression arg = expression.pop();
if (arg instanceof AttributeExprEx) {
AttributeExprEx variable = (AttributeExprEx) arg;
NodeMaker nm = variable.getNodeMaker();
DetermineNodeType filter = new DetermineNodeType();
nm.describeSelf(filter);
String lang = filter.getLanguage();
logger.debug("lang " + lang);
if (lang == null) lang = "";
// NodeValue.makeString(lang); TODO better?
Node node = Node.createLiteral(lang);
ConstantEx constantEx = new ConstantEx(NodeValue.makeNode(node).asString(), node);
logger.debug("pushing " + constantEx);
expression.push(constantEx);
} else if (arg instanceof ConstantEx) {
ConstantEx constant = (ConstantEx) arg;
Node node = constant.getNode();
if (!node.isLiteral()) {
// type error, return false?
logger.warn("type error: " + node + " is not a literal, returning FALSE");
expression.push(Expression.FALSE);
return;
}
String lang = node.getLiteralLanguage();
logger.debug("lang " + lang);
if (lang == null) lang = "";
node = Node.createLiteral(lang);
ConstantEx constantEx = new ConstantEx(NodeValue.makeNode(node).asString(), node);
logger.debug("pushing " + constantEx);
expression.push(constantEx);
} else {
conversionFailed(expr);
}
}
/*
* See http://www.w3.org/TR/rdf-sparql-query paragraph 11.4.3
*
* "(ISBLANK) Returns true if term is a blank node. Returns false otherwise."
*
* @see http://www.w3.org/TR/rdf-sparql-query
*/
private void convertIsBlank(E_IsBlank expr) {
logger.debug("convertIsBlank " + expr.toString());
expr.getArg().visit(this);
Expression arg = expression.pop();
if (arg instanceof AttributeExprEx) {
AttributeExprEx variable = (AttributeExprEx) arg;
NodeMaker nm = variable.getNodeMaker();
DetermineNodeType filter = new DetermineNodeType();
nm.describeSelf(filter);
expression.push(filter.isLimittedToBlankNodes() ? Expression.TRUE : Expression.FALSE);
} else if (arg instanceof ConstantEx) {
ConstantEx constant = (ConstantEx) arg;
Node node = constant.getNode();
expression.push(node.isBlank() ? Expression.TRUE : Expression.FALSE);
} else {
conversionFailed(expr);
}
}
private void convertNotEquals(E_NotEquals expr) {
logger.debug("convertNotEquals " + expr.toString());
expr.getArg1().visit(this);
expr.getArg2().visit(this);
Expression e2 = expression.pop();
Expression e1 = expression.pop();
// TODO Expression.FALSE and Expression.TRUE are not constants
if (e1.equals(Expression.FALSE)) e1 = CONSTANT_FALSE;
else if (e1.equals(Expression.TRUE)) e1 = CONSTANT_TRUE;
if (e2.equals(Expression.FALSE)) e2 = CONSTANT_FALSE;
else if (e2.equals(Expression.TRUE)) e2 = CONSTANT_TRUE;
if (e1 instanceof AttributeExprEx && e2 instanceof Constant
|| e2 instanceof AttributeExprEx && e1 instanceof Constant) {
AttributeExprEx variable;
ConstantEx constant;
if (e1 instanceof AttributeExprEx) {
variable = (AttributeExprEx) e1;
constant = (ConstantEx) e2;
} else {
variable = (AttributeExprEx) e2;
constant = (ConstantEx) e1;
}
logger.debug("isNotEqual(" + variable + ", " + constant + ")");
NodeMaker nm = variable.getNodeMaker();
if (nm instanceof TypedNodeMaker) {
ValueMaker vm = ((TypedNodeMaker) nm).valueMaker();
Node node = constant.getNode();
logger.debug("checking " + node + " with " + nm);
if (XSD.isNumeric(node)) {
DetermineNodeType filter = new DetermineNodeType();
nm.describeSelf(filter);
RDFDatatype datatype = filter.getDatatype();
if (datatype != null && XSD.isNumeric(datatype)) {
RDFDatatype numericType = XSD.getNumericType(datatype, node.getLiteralDatatype());
nm = cast(nm, numericType);
node = XSD.cast(node, numericType);
}
}
boolean empty = nm.selectNode(node, RelationalOperators.DUMMY).equals(NodeMaker.EMPTY);
logger.debug("result " + new Boolean(empty));
if (!empty) {
if (node.isURI()) expression.push(new Negation(vm.valueExpression(node.getURI())));
else if (node.isLiteral()) {
if (XSD.isSupported(node.getLiteralDatatype()))
expression.push(new Negation(vm.valueExpression(constant.value())));
else // type = boolean or an unknown type
conversionFailed("cannot compare values of type " + node.getLiteralDatatypeURI(), expr);
} else conversionFailed(expr); // TODO blank nodes?
return;
} else {
expression.push(Expression.TRUE);
return;
}
}
} else if (e1 instanceof ConstantEx && e2 instanceof ConstantEx) {
logger.debug("isNotEqual(" + e1 + ", " + e2 + ")");
Node c1 = ((ConstantEx) e1).getNode();
Node c2 = ((ConstantEx) e2).getNode();
boolean equals;
if (XSD.isNumeric(c1) && XSD.isNumeric(c2)) {
RDFDatatype datatype = XSD.getNumericType(c1.getLiteralDatatype(), c2.getLiteralDatatype());
equals = XSD.cast(c1, datatype).equals(XSD.cast(c2, datatype));
} else if (isSimpleLiteral(c1) && isSimpleLiteral(c2)) {
equals = c1.getLiteralValue().equals(c2.getLiteralValue());
} else if (XSD.isString(c1) && XSD.isString(c2)) {
equals = c1.getLiteralValue().equals(c2.getLiteralValue());
} else {
try {
equals = NodeFunctions.rdfTermEquals(c1, c2);
} catch (ExprEvalException e) {
equals = false;
}
}
logger.debug("constants equal? " + new Boolean(equals));
expression.push(equals ? Expression.FALSE : Expression.TRUE);
return;
} else if (e1 instanceof AttributeExprEx && e2 instanceof AttributeExprEx) {
logger.debug("isNotEqual(" + e1 + ", " + e2 + ")");
AttributeExprEx variable1 = (AttributeExprEx) e1;
AttributeExprEx variable2 = (AttributeExprEx) e2;
NodeMaker nm1 = variable1.getNodeMaker();
NodeMaker nm2 = variable2.getNodeMaker();
DetermineNodeType filter1 = new DetermineNodeType();
nm1.describeSelf(filter1);
RDFDatatype datatype1 = filter1.getDatatype();
DetermineNodeType filter2 = new DetermineNodeType();
nm2.describeSelf(filter2);
RDFDatatype datatype2 = filter2.getDatatype();
if (datatype1 != null
&& XSD.isNumeric(datatype1)
&& datatype2 != null
&& XSD.isNumeric(datatype2)) {
RDFDatatype numericType = XSD.getNumericType(filter1.getDatatype(), filter2.getDatatype());
nm1 = cast(nm1, numericType);
nm2 = cast(nm2, numericType);
}
NodeSetConstraintBuilder nodeSet = new NodeSetConstraintBuilder();
nm1.describeSelf(nodeSet);
nm2.describeSelf(nodeSet);
if (nodeSet.isEmpty()) {
logger.debug("nodes " + nm1 + " " + nm2 + " incompatible");
expression.push(Expression.TRUE);
return;
}
}
expression.push(new Negation(Equality.create(e1, e2)));
}
