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

@Override
public void meet(final StatementPattern node) throws Exception {
    super.meet(node);

    final Var subjectVar = node.getSubjectVar();
    final RangeValue subjRange = rangeValues.get(subjectVar);
    final Var predVar = node.getPredicateVar();
    final RangeValue predRange = rangeValues.get(predVar);
    final Var objVar = node.getObjectVar();
    final RangeValue objRange = rangeValues.get(objVar);
    if(subjRange != null) {
        subjectVar.setValue(new RangeIRI(subjRange));//Assumes no blank nodes can be ranges
    }
    if(predRange != null) {
        predVar.setValue(new RangeIRI(predRange));
    }
    if(objRange != null) {
        objVar.setValue(objRange);
    }
}
 

/**
 * Clone the specified variable and attach bindings, moreover change name of variable
 * by appending "_varId" to it.
 * 
 * @param sb
 * @param var
 * @param varNames
 * @param bindings
 * 
 * @return
 */
protected static Var appendVarId(Var var, String varID, Set<String> varNames, BindingSet bindings) {
	Var res = var.clone();
	if (!var.hasValue()) {
		if (bindings.hasBinding(var.getName())) {
			res.setValue( bindings.getValue(var.getName()) );
		} else {
			String newName = var.getName() + "_" + varID;
			varNames.add(newName);
			res.setName(newName);
		}			
	}
	return res;
}
 

/**
 * Clone the specified variable and attach bindings.
 *
 * @param var
 * @param varNames
 * @param bindings
 *
 * @return the variable
 *
 */
protected static Var appendVar(Var var, Set<String> varNames, BindingSet bindings) {
	Var res = var.clone();
	if (!var.hasValue()) {
		if (bindings.hasBinding(var.getName())) {
			res.setValue(bindings.getValue(var.getName()));
		} else {
			varNames.add(var.getName());
		}
	}
	return res;
}
 

/**
 * Clone the specified variable and attach bindings, moreover change name of variable by appending "_varId" to it.
 *
 * @param var
 * @param varID
 * @param varNames
 * @param bindings
 *
 * @return the variable
 */
protected static Var appendVarId(Var var, String varID, Set<String> varNames, BindingSet bindings) {
	Var res = var.clone();
	if (!var.hasValue()) {
		if (bindings.hasBinding(var.getName())) {
			res.setValue(bindings.getValue(var.getName()));
		} else {
			String newName = var.getName() + "_" + varID;
			varNames.add(newName);
			res.setName(newName);
		}
	}
	return res;
}
 

@Override
public void meet(Var node) throws QueryEvaluationException {
	if (node.hasValue()) {
		if (bindings.hasBinding(node.getName())) {
			node.setValue(bindings.getValue(node.getName()));
		}
	} else {
		freeVars.add(node.getName());
	}
	super.meet(node);
}
 

/**
 * Applies generally applicable optimizations to the supplied query: variable assignments are inlined.
 */
@Override
public void optimize(TupleExpr tupleExpr, Dataset dataset, BindingSet bindings) {
	ConstantVisitor visitor = new ConstantVisitor();
	tupleExpr.visit(visitor);
	Set<String> varsBefore = visitor.varNames;

	VarNameCollector varCollector = new VarNameCollector();
	tupleExpr.visit(varCollector);
	Set<String> varsAfter = varCollector.varNames;

	if (varsAfter.size() < varsBefore.size()) {
		varsBefore.removeAll(varsAfter);
		for (ProjectionElemList projElems : visitor.projElemLists) {
			for (ProjectionElem projElem : projElems.getElements()) {
				String name = projElem.getSourceName();
				if (varsBefore.contains(name)) {
					UnaryTupleOperator proj = (UnaryTupleOperator) projElems.getParentNode();
					Extension ext = new Extension(proj.getArg());
					proj.setArg(ext);
					Var lostVar = new Var(name);
					Value value = bindings.getValue(name);
					if (value != null) {
						lostVar.setValue(value);
					}
					ext.addElement(new ExtensionElem(lostVar, name));
				}
			}
		}
	}
}
 

@Override
public void meet(Var var) {
	if (!var.hasValue() && bindings.hasBinding(var.getName())) {
		Value value = bindings.getValue(var.getName());
		var.setValue(value);
	}
}
 

/**
 * Creates an (anonymous) Var representing a constant value. The variable name will be derived from the actual value
 * to guarantee uniqueness.
 *
 * @param value
 * @return an (anonymous) Var representing a constant value.
 */
public static Var createConstVar(Value value) {
	String varName = getConstVarName(value);
	Var var = new Var(varName);
	var.setConstant(true);
	var.setAnonymous(true);
	var.setValue(value);
	return var;
}
 

public void meet(Var var) {
    if (!var.isConstant() && hMap.containsKey(var.getName())) {
        String val = hMap.get(var.getName());
        if (VarNameUtils.isConstant(val)) {
           var.setName(val);
           var.setValue(valMap.get(val));
           var.setAnonymous(true); //TODO this might be a hack -- when are Vars not anonymous?
        } else {
            var.setName(val);
        }
    }
}
 

@Override
public void meet(Var var) {
	if (var.getName().equals(varName)) {
		var.setValue(value);
	}
}
 

private Var createConstantVar(Value value) {
	Var var = new Var("-const-" + constantVarID++);
	var.setAnonymous(true);
	var.setValue(value);
	return var;
}
 

/**
 * Clone the specified variable and attach bindings.
 *  
 * @param sb
 * @param var
 * @param varNames
 * @param bindings
 * 
 * @return

 */
protected static Var appendVar(Var var, Set<String> varNames, BindingSet bindings) {
	Var res = var.clone();
	if (!var.hasValue()) {
		if (bindings.hasBinding(var.getName()))
			res.setValue( bindings.getValue(var.getName()) );
		else 
			varNames.add(var.getName());			
	}
	return res;
}