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Example 1 with DefaultVariableGenerator

use of fr.lirmm.graphik.graal.core.DefaultVariableGenerator in project graal by graphik-team.

the class RdbmsAtomIterator method hasNext.

// /////////////////////////////////////////////////////////////////////////
// METHODS
// /////////////////////////////////////////////////////////////////////////
@Override
public boolean hasNext() throws IteratorException {
    if (!this.hasNextCallDone) {
        this.hasNextCallDone = true;
        while (this.predicateIt.hasNext() && (this.atomIt == null || !this.atomIt.hasNext())) {
            Predicate p = predicateIt.next();
            List<Term> terms = new LinkedList<Term>();
            VariableGenerator gen = new DefaultVariableGenerator("X");
            for (int i = 0; i < p.getArity(); ++i) {
                terms.add(gen.getFreshSymbol());
            }
            InMemoryAtomSet atomSet = new LinkedListAtomSet();
            Atom atom = new DefaultAtom(p, terms);
            atomSet.add(atom);
            ConjunctiveQuery query = DefaultConjunctiveQueryFactory.instance().create(atomSet);
            SqlHomomorphism solver = SqlHomomorphism.instance();
            try {
                this.atomIt = new SubstitutionIterator2AtomIterator(atom, solver.execute(query, this.store));
            } catch (HomomorphismException e) {
                throw new IteratorException(e);
            }
        }
    }
    return this.atomIt != null && this.atomIt.hasNext();
}
Also used : DefaultVariableGenerator(fr.lirmm.graphik.graal.core.DefaultVariableGenerator) IteratorException(fr.lirmm.graphik.util.stream.IteratorException) HomomorphismException(fr.lirmm.graphik.graal.api.homomorphism.HomomorphismException) DefaultAtom(fr.lirmm.graphik.graal.core.DefaultAtom) LinkedListAtomSet(fr.lirmm.graphik.graal.core.atomset.LinkedListAtomSet) SqlHomomorphism(fr.lirmm.graphik.graal.store.rdbms.homomorphism.SqlHomomorphism) Term(fr.lirmm.graphik.graal.api.core.Term) SubstitutionIterator2AtomIterator(fr.lirmm.graphik.graal.core.stream.SubstitutionIterator2AtomIterator) LinkedList(java.util.LinkedList) DefaultAtom(fr.lirmm.graphik.graal.core.DefaultAtom) Atom(fr.lirmm.graphik.graal.api.core.Atom) Predicate(fr.lirmm.graphik.graal.api.core.Predicate) InMemoryAtomSet(fr.lirmm.graphik.graal.api.core.InMemoryAtomSet) DefaultVariableGenerator(fr.lirmm.graphik.graal.core.DefaultVariableGenerator) VariableGenerator(fr.lirmm.graphik.graal.api.core.VariableGenerator) ConjunctiveQuery(fr.lirmm.graphik.graal.api.core.ConjunctiveQuery)

Aggregations

Atom (fr.lirmm.graphik.graal.api.core.Atom)1 ConjunctiveQuery (fr.lirmm.graphik.graal.api.core.ConjunctiveQuery)1 InMemoryAtomSet (fr.lirmm.graphik.graal.api.core.InMemoryAtomSet)1 Predicate (fr.lirmm.graphik.graal.api.core.Predicate)1 Term (fr.lirmm.graphik.graal.api.core.Term)1 VariableGenerator (fr.lirmm.graphik.graal.api.core.VariableGenerator)1 HomomorphismException (fr.lirmm.graphik.graal.api.homomorphism.HomomorphismException)1 DefaultAtom (fr.lirmm.graphik.graal.core.DefaultAtom)1 DefaultVariableGenerator (fr.lirmm.graphik.graal.core.DefaultVariableGenerator)1 LinkedListAtomSet (fr.lirmm.graphik.graal.core.atomset.LinkedListAtomSet)1 SubstitutionIterator2AtomIterator (fr.lirmm.graphik.graal.core.stream.SubstitutionIterator2AtomIterator)1 SqlHomomorphism (fr.lirmm.graphik.graal.store.rdbms.homomorphism.SqlHomomorphism)1 IteratorException (fr.lirmm.graphik.util.stream.IteratorException)1 LinkedList (java.util.LinkedList)1