Examples with FilterIterator fr.lirmm.graphik.util.stream.filter.FilterIterator used on opensource projects

Example 1 with FilterIterator

use of fr.lirmm.graphik.util.stream.filter.FilterIterator in project graal by graphik-team.

the class AtomicQueryHomomorphismWithNegatedParts method execute.

// /////////////////////////////////////////////////////////////////////////
// HOMOMORPHISM METHODS
// /////////////////////////////////////////////////////////////////////////
public CloseableIterator<Substitution> execute(ConjunctiveQueryWithNegatedParts query, AtomSet data, RulesCompilation compilation) throws HomomorphismException {
    try {
        Atom atom = query.getPositivePart().iterator().next();
        List<Term> ans = query.getAnswerVariables();
        List<CloseableIterator<Substitution>> iteratorsList = new LinkedList<CloseableIterator<Substitution>>();
        for (Pair<Atom, Substitution> im : compilation.getRewritingOf(atom)) {
            iteratorsList.add(new ConverterCloseableIterator<Atom, Substitution>(data.match(im.getLeft()), new Atom2SubstitutionConverter(im.getLeft(), ans, im.getRight())));
        }
        CloseableIterator<Substitution> subIt = new CloseableIteratorAggregator<Substitution>(new CloseableIteratorAdapter<CloseableIterator<Substitution>>(iteratorsList.iterator()));
        // manage negative parts
        Set<Variable> variables = query.getPositivePart().getVariables();
        @SuppressWarnings("rawtypes") Filter[] filters = new Filter[query.getNegatedParts().size()];
        int i = 0;
        for (InMemoryAtomSet negPart : query.getNegatedParts()) {
            Set<Variable> frontier = SetUtils.intersection(variables, negPart.getVariables());
            filters[i++] = new NegFilter(negPart, frontier, data, compilation);
        }
        @SuppressWarnings("unchecked") Filter<Substitution> filter = new AndFilter<Substitution>(filters);
        return new FilterIterator<Substitution, Substitution>(subIt, filter);
    } catch (AtomSetException e) {
        throw new HomomorphismException(e);
    }
}