Examples with CumulativeState ai.grakn.graql.internal.reasoner.state.CumulativeState used on opensource projects

Example 1 with CumulativeState

use of ai.grakn.graql.internal.reasoner.state.CumulativeState in project grakn by graknlabs.

the class ReasonerQueryImpl method queryStateIterator.

/**
 * @param parent parent state
 * @param subGoals set of visited sub goals
 * @param cache query cache
 * @return query state iterator (db iter + unifier + state iter) for this query
 */
public Pair<Iterator<ResolutionState>, MultiUnifier> queryStateIterator(QueryStateBase parent, Set<ReasonerAtomicQuery> subGoals, QueryCache<ReasonerAtomicQuery> cache) {
    Iterator<AnswerState> dbIterator;
    Iterator<QueryStateBase> subGoalIterator;
    if (!this.isRuleResolvable()) {
        dbIterator = this.getQuery().stream().map(ans -> ans.explain(new JoinExplanation(this, ans))).map(ans -> new AnswerState(ans, parent.getUnifier(), parent)).iterator();
        subGoalIterator = Collections.emptyIterator();
    } else {
        dbIterator = Collections.emptyIterator();
        LinkedList<ReasonerQueryImpl> subQueries = new ResolutionPlan(this).queryPlan();
        LOG.trace("CQ plan:\n" + subQueries.stream().map(sq -> sq.toString() + (sq.isRuleResolvable() ? "*" : "")).collect(Collectors.joining("\n")));
        subGoalIterator = Iterators.singletonIterator(new CumulativeState(subQueries, new QueryAnswer(), parent.getUnifier(), parent, subGoals, cache));
    }
    return new Pair<>(Iterators.concat(dbIterator, subGoalIterator), new MultiUnifierImpl());
}