Examples with BasicPattern org.apache.jena.sparql.core.BasicPattern used on opensource projects

Example 36 with BasicPattern

use of org.apache.jena.sparql.core.BasicPattern in project jena by apache.

the class AlgebraExec method main.

public static void main(String[] argv) {
    String BASE = "http://example/";
    BasicPattern bp = new BasicPattern();
    Var var_x = Var.alloc("x");
    Var var_z = Var.alloc("z");
    // ---- Build expression
    bp.add(new Triple(var_x, NodeFactory.createURI(BASE + "p"), var_z));
    Op op = new OpBGP(bp);
    //Expr expr = ExprUtils.parse("?z < 2 ") ;
    Expr expr = new E_LessThan(new ExprVar(var_z), NodeValue.makeNodeInteger(2));
    op = OpFilter.filter(expr, op);
    // ---- Example setup
    Model m = makeModel();
    m.write(System.out, "TTL");
    System.out.println("--------------");
    System.out.print(op);
    System.out.println("--------------");
    // ---- Execute expression
    QueryIterator qIter = Algebra.exec(op, m.getGraph());
    // -------- Either read the query iterator directly ...
    if (false) {
        for (; qIter.hasNext(); ) {
            Binding b = qIter.nextBinding();
            Node n = b.get(var_x);
            System.out.println(NodeFmtLib.displayStr(n));
            System.out.println(b);
        }
        qIter.close();
    } else {
        // -------- Or make ResultSet from it (but not both - reading an
        //          iterator consumes the current solution)
        List<String> varNames = new ArrayList<>();
        varNames.add("x");
        varNames.add("z");
        ResultSet rs = new ResultSetStream(varNames, m, qIter);
        ResultSetFormatter.out(rs);
        qIter.close();
    }
    System.exit(0);
}

Example 37 with BasicPattern

use of org.apache.jena.sparql.core.BasicPattern in project jena by apache.

the class QueryIterPropertyTable method sort.

private Collection<BasicPattern> sort(BasicPattern pattern) {
    HashMap<Node, BasicPattern> map = new HashMap<>();
    for (Triple triple : pattern.getList()) {
        Node subject = triple.getSubject();
        if (!map.containsKey(subject)) {
            List<Triple> triples = new ArrayList<>();
            BasicPattern p = BasicPattern.wrap(triples);
            map.put(subject, p);
            p.add(triple);
        } else {
            map.get(subject).add(triple);
        }
    }
    return map.values();
}

Example 38 with BasicPattern

use of org.apache.jena.sparql.core.BasicPattern in project jena by apache.

the class TransformMergeBGPs method merge.

private static BasicPattern merge(BasicPattern p1, BasicPattern p2) {
    if (p1 == null || p2 == null)
        return null;
    BasicPattern p = new BasicPattern();
    p.addAll(p1);
    p.addAll(p2);
    return p;
}

Example 39 with BasicPattern

use of org.apache.jena.sparql.core.BasicPattern in project jena by apache.

the class TransformReorder method transform.

/**
	 * Transforms Quad Patterns with the reordering
	 */
@Override
public Op transform(OpQuadPattern opQuadPattern) {
    BasicPattern pattern = opQuadPattern.getBasicPattern();
    if (pattern.size() < 2)
        return opQuadPattern;
    BasicPattern pattern2 = reorder.reorder(pattern);
    return new OpQuadPattern(opQuadPattern.getGraphNode(), pattern2);
}

Example 40 with BasicPattern

use of org.apache.jena.sparql.core.BasicPattern in project jena by apache.

the class TransformFilterPlacementConservative method transformFilterQuadPattern.

private static Op transformFilterQuadPattern(ExprList exprs, Set<Var> patternVarsScope, Node graphNode, BasicPattern pattern) {
    // Any filters that depend on no variables.
    Op op = insertAnyFilter(exprs, patternVarsScope, null);
    if (Var.isVar(graphNode)) {
        // Add in the graph node of the quad block.
        // It's picked up after the first triple is processed.
        VarUtils.addVar(patternVarsScope, Var.alloc(graphNode));
    }
    for (Triple triple : pattern) {
        OpQuadPattern opQuad = getQuads(op);
        if (opQuad == null) {
            opQuad = new OpQuadPattern(graphNode, new BasicPattern());
            op = OpSequence.create(op, opQuad);
        }
        opQuad.getBasicPattern().add(triple);
        // Update variables in scope.
        VarUtils.addVarsFromTriple(patternVarsScope, triple);
        // Attempt to place any filters
        op = insertAnyFilter(exprs, patternVarsScope, op);
    }
    return op;
}