Examples with ValueExpr org.eclipse.rdf4j.query.algebra.ValueExpr used on opensource projects

Example 51 with ValueExpr

use of org.eclipse.rdf4j.query.algebra.ValueExpr in project rdf4j by eclipse.

the class TupleExprBuilder method visit.

@Override
public Object visit(ASTPathSequence pathSeqNode, Object data) throws VisitorException {
    ValueExpr subject = (ValueExpr) data;
    Var subjVar = mapValueExprToVar(subject);
    // check if we should invert subject and object.
    boolean invertSequence = checkInverse(pathSeqNode);
    @SuppressWarnings("unchecked") List<ValueExpr> objectList = (List<ValueExpr>) getObjectList(pathSeqNode).jjtAccept(this, null);
    List<ASTPathElt> pathElements = pathSeqNode.getPathElements();
    int pathLength = pathElements.size();
    GraphPattern pathSequencePattern = new GraphPattern(graphPattern);
    Scope scope = pathSequencePattern.getStatementPatternScope();
    Var contextVar = pathSequencePattern.getContextVar();
    Var startVar = subjVar;
    for (int i = 0; i < pathLength; i++) {
        ASTPathElt pathElement = pathElements.get(i);
        ASTPathMod pathMod = pathElement.getPathMod();
        long lowerBound = Long.MIN_VALUE;
        long upperBound = Long.MIN_VALUE;
        if (pathMod != null) {
            lowerBound = pathMod.getLowerBound();
            upperBound = pathMod.getUpperBound();
            if (upperBound == Long.MIN_VALUE) {
                upperBound = lowerBound;
            } else if (lowerBound == Long.MIN_VALUE) {
                lowerBound = upperBound;
            }
        }
        if (pathElement.isNegatedPropertySet()) {
            // create a temporary negated property set object and set the
            // correct subject and object vars to continue
            // the path sequence.
            NegatedPropertySet nps = new NegatedPropertySet();
            nps.setScope(scope);
            nps.setSubjectVar(startVar);
            nps.setContextVar(contextVar);
            for (Node child : pathElement.jjtGetChildren()) {
                if (child instanceof ASTPathMod) {
                    // skip the modifier
                    continue;
                }
                nps.addPropertySetElem((PropertySetElem) child.jjtAccept(this, data));
            }
            Var[] objVarReplacement = null;
            if (i == pathLength - 1) {
                if (objectList.contains(subjVar)) {
                    // See SES-1685
                    Var objVar = mapValueExprToVar(objectList.get(objectList.indexOf(subjVar)));
                    objVarReplacement = new Var[] { objVar, createAnonVar() };
                    objectList.remove(objVar);
                    objectList.add(objVarReplacement[1]);
                } else {
                    nps.setObjectList(objectList);
                }
            } else {
                // not last element in path.
                Var nextVar = createAnonVar();
                List<ValueExpr> nextVarList = new ArrayList<ValueExpr>();
                nextVarList.add(nextVar);
                nps.setObjectList(nextVarList);
                startVar = nextVar;
            }
            // convert the NegatedPropertySet to a proper TupleExpr
            TupleExpr te = createTupleExprForNegatedPropertySet(nps, i);
            if (objVarReplacement != null) {
                SameTerm condition = new SameTerm(objVarReplacement[0], objVarReplacement[1]);
                pathSequencePattern.addConstraint(condition);
            }
            for (ValueExpr object : objectList) {
                Var objVar = mapValueExprToVar(object);
                te = handlePathModifiers(scope, subjVar, te, objVar, contextVar, lowerBound, upperBound);
            }
            pathSequencePattern.addRequiredTE(te);
        } else if (pathElement.isNestedPath()) {
            GraphPattern parentGP = graphPattern;
            graphPattern = new GraphPattern(parentGP);
            if (i == pathLength - 1) {
                // last element in the path
                pathElement.jjtGetChild(0).jjtAccept(this, startVar);
                TupleExpr te = graphPattern.buildTupleExpr();
                for (ValueExpr object : objectList) {
                    Var objVar = mapValueExprToVar(object);
                    if (objVar.equals(subjVar)) {
                        // see SES-1685
                        Var objVarReplacement = createAnonVar();
                        te = handlePathModifiers(scope, startVar, te, objVarReplacement, contextVar, lowerBound, upperBound);
                        SameTerm condition = new SameTerm(objVar, objVarReplacement);
                        pathSequencePattern.addConstraint(condition);
                    } else {
                        te = handlePathModifiers(scope, startVar, te, objVar, contextVar, lowerBound, upperBound);
                    }
                    pathSequencePattern.addRequiredTE(te);
                }
            } else {
                // not the last element in the path, introduce an anonymous
                // var
                // to connect.
                Var nextVar = createAnonVar();
                pathElement.jjtGetChild(0).jjtAccept(this, startVar);
                TupleExpr te = graphPattern.buildTupleExpr();
                // replace all object list occurrences with the intermediate
                // var.
                te = replaceVarOccurrence(te, objectList, nextVar);
                te = handlePathModifiers(scope, startVar, te, nextVar, contextVar, lowerBound, upperBound);
                pathSequencePattern.addRequiredTE(te);
                startVar = nextVar;
            }
            graphPattern = parentGP;
        } else {
            ValueExpr pred = (ValueExpr) pathElement.jjtAccept(this, data);
            Var predVar = mapValueExprToVar(pred);
            TupleExpr te;
            if (i == pathLength - 1) {
                // objects
                for (ValueExpr object : objectList) {
                    Var objVar = mapValueExprToVar(object);
                    boolean replaced = false;
                    // to avoid problems in cyclic paths
                    if (objVar.equals(subjVar)) {
                        objVar = createAnonVar();
                        replaced = true;
                    }
                    Var endVar = objVar;
                    if (invertSequence) {
                        endVar = subjVar;
                        if (startVar.equals(subjVar)) {
                            // inverted path sequence of length 1.
                            startVar = objVar;
                        }
                    }
                    if (pathElement.isInverse()) {
                        te = new StatementPattern(scope, endVar, predVar, startVar, contextVar);
                        te = handlePathModifiers(scope, endVar, te, startVar, contextVar, lowerBound, upperBound);
                    } else {
                        te = new StatementPattern(scope, startVar, predVar, endVar, contextVar);
                        te = handlePathModifiers(scope, startVar, te, endVar, contextVar, lowerBound, upperBound);
                    }
                    if (replaced) {
                        SameTerm condition = new SameTerm(objVar, mapValueExprToVar(object));
                        pathSequencePattern.addConstraint(condition);
                    }
                    pathSequencePattern.addRequiredTE(te);
                }
            } else {
                // not the last element in the path, introduce an anonymous
                // var
                // to connect.
                Var nextVar = createAnonVar();
                if (invertSequence && startVar.equals(subjVar)) {
                    // sequence
                    for (ValueExpr object : objectList) {
                        Var objVar = mapValueExprToVar(object);
                        startVar = objVar;
                        if (pathElement.isInverse()) {
                            Var temp = startVar;
                            startVar = nextVar;
                            nextVar = temp;
                        }
                        te = new StatementPattern(scope, startVar, predVar, nextVar, contextVar);
                        te = handlePathModifiers(scope, startVar, te, nextVar, contextVar, lowerBound, upperBound);
                        pathSequencePattern.addRequiredTE(te);
                    }
                } else {
                    if (pathElement.isInverse()) {
                        final Var oldStartVar = startVar;
                        startVar = nextVar;
                        nextVar = oldStartVar;
                    }
                    te = new StatementPattern(scope, startVar, predVar, nextVar, contextVar);
                    te = handlePathModifiers(scope, startVar, te, nextVar, contextVar, lowerBound, upperBound);
                    pathSequencePattern.addRequiredTE(te);
                }
                // set the subject for the next element in the path.
                startVar = (pathElement.isInverse() ? startVar : nextVar);
            }
        }
    }
    // add the created path sequence to the graph pattern.
    for (TupleExpr te : pathSequencePattern.getRequiredTEs()) {
        graphPattern.addRequiredTE(te);
    }
    if (pathSequencePattern.getConstraints() != null) {
        for (ValueExpr constraint : pathSequencePattern.getConstraints()) {
            graphPattern.addConstraint(constraint);
        }
    }
    return null;
}

Example 52 with ValueExpr

use of org.eclipse.rdf4j.query.algebra.ValueExpr in project rdf4j by eclipse.

the class TupleExprBuilder method visit.

@Override
public Coalesce visit(ASTCoalesce node, Object data) throws VisitorException {
    Coalesce coalesce = new Coalesce();
    int noOfArgs = node.jjtGetNumChildren();
    for (int i = 0; i < noOfArgs; i++) {
        ValueExpr arg = (ValueExpr) node.jjtGetChild(i).jjtAccept(this, data);
        coalesce.addArgument(arg);
    }
    return coalesce;
}

Example 53 with ValueExpr

use of org.eclipse.rdf4j.query.algebra.ValueExpr in project rdf4j by eclipse.

the class TupleExprBuilder method visit.

@Override
public Object visit(ASTPropertyList propListNode, Object data) throws VisitorException {
    ValueExpr subject = (ValueExpr) data;
    ValueExpr predicate = (ValueExpr) propListNode.getVerb().jjtAccept(this, null);
    @SuppressWarnings("unchecked") List<ValueExpr> objectList = (List<ValueExpr>) propListNode.getObjectList().jjtAccept(this, null);
    Var subjVar = mapValueExprToVar(subject);
    Var predVar = mapValueExprToVar(predicate);
    for (ValueExpr object : objectList) {
        Var objVar = mapValueExprToVar(object);
        graphPattern.addRequiredSP(subjVar, predVar, objVar);
    }
    ASTPropertyList nextPropList = propListNode.getNextPropertyList();
    if (nextPropList != null) {
        nextPropList.jjtAccept(this, subject);
    }
    return graphPattern.buildTupleExpr();
}

Example 54 with ValueExpr

use of org.eclipse.rdf4j.query.algebra.ValueExpr in project rdf4j by eclipse.

the class TupleExprBuilder method visit.

@Override
public Object visit(ASTBind node, Object data) throws VisitorException {
    // bind expression
    ValueExpr ve = (ValueExpr) node.jjtGetChild(0).jjtAccept(this, data);
    // 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;
        // 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;
}

Example 55 with ValueExpr

use of org.eclipse.rdf4j.query.algebra.ValueExpr in project rdf4j by eclipse.

the class TupleExprBuilder method visit.

@Override
public SameTerm visit(ASTSameTerm node, Object data) throws VisitorException {
    ValueExpr leftArg = (ValueExpr) node.jjtGetChild(0).jjtAccept(this, null);
    ValueExpr rightArg = (ValueExpr) node.jjtGetChild(1).jjtAccept(this, null);
    return new SameTerm(leftArg, rightArg);
}