Examples with IndexedInstanceStorage at.ac.tuwien.kr.alpha.core.grounder.IndexedInstanceStorage used on opensource projects

Example 1 with IndexedInstanceStorage

use of at.ac.tuwien.kr.alpha.core.grounder.IndexedInstanceStorage in project Alpha by alpha-asp.

the class StratifiedEvaluation method evaluateComponent.

private void evaluateComponent(ComponentGraph.SCComponent comp) {
    LOGGER.debug("Evaluating component {}", comp);
    ComponentEvaluationInfo evaluationInfo = getRulesToEvaluate(comp);
    if (evaluationInfo.isEmpty()) {
        LOGGER.debug("No rules to evaluate for component {}", comp);
        return;
    }
    // Rules outside of dependency cycles only need to be evaluated once.
    if (!evaluationInfo.nonRecursiveRules.isEmpty()) {
        prepareInitialEvaluation(evaluationInfo.nonRecursiveRules);
        evaluateRules(evaluationInfo.nonRecursiveRules, true);
        for (IndexedInstanceStorage instanceStorage : workingMemory.modified()) {
            // Directly record all newly derived instances as additional facts.
            for (Instance recentlyAddedInstance : instanceStorage.getRecentlyAddedInstances()) {
                additionalFacts.add(Atoms.newBasicAtom(instanceStorage.getPredicate(), recentlyAddedInstance.terms));
            }
            instanceStorage.markRecentlyAddedInstancesDone();
        }
    }
    boolean isInitialRun = true;
    if (!evaluationInfo.recursiveRules.isEmpty()) {
        do {
            // evaluate these until nothing new can be derived any more.
            if (isInitialRun) {
                prepareInitialEvaluation(evaluationInfo.recursiveRules);
            }
            evaluateRules(evaluationInfo.recursiveRules, isInitialRun);
            isInitialRun = false;
            modifiedInLastEvaluationRun = new HashMap<>();
            // Since we are stratified we never have to backtrack, therefore just collect the added instances.
            for (IndexedInstanceStorage instanceStorage : workingMemory.modified()) {
                // Directly record all newly derived instances as additional facts.
                for (Instance recentlyAddedInstance : instanceStorage.getRecentlyAddedInstances()) {
                    additionalFacts.add(Atoms.newBasicAtom(instanceStorage.getPredicate(), recentlyAddedInstance.terms));
                }
                modifiedInLastEvaluationRun.putIfAbsent(instanceStorage.getPredicate(), new LinkedHashSet<>());
                modifiedInLastEvaluationRun.get(instanceStorage.getPredicate()).addAll(instanceStorage.getRecentlyAddedInstances());
                instanceStorage.markRecentlyAddedInstancesDone();
            }
        // If the evaluation of rules did not modify the working memory we have a fixed-point.
        } while (!workingMemory.modified().isEmpty());
    }
    LOGGER.debug("Evaluation done - reached a fixed point on component {}", comp);
    SetUtils.union(evaluationInfo.nonRecursiveRules, evaluationInfo.recursiveRules).forEach((rule) -> solvedRuleIds.add(rule.getRuleId()));
}

Example 2 with IndexedInstanceStorage

use of at.ac.tuwien.kr.alpha.core.grounder.IndexedInstanceStorage in project Alpha by alpha-asp.

the class StratifiedEvaluation method prepareInitialEvaluation.

/**
 * To be called at the start of evaluateComponent. Adds all known instances of the predicates occurring in the given set
 * of rules to the "modifiedInLastEvaluationRun" map in order to "bootstrap" incremental grounding, i.e. making sure
 * that those instances are taken into account for ground substitutions by evaluateRule.
 */
private void prepareInitialEvaluation(Set<CompiledRule> rulesToEvaluate) {
    modifiedInLastEvaluationRun = new HashMap<>();
    for (CompiledRule rule : rulesToEvaluate) {
        // Register rule head instances.
        Predicate headPredicate = rule.getHeadAtom().getPredicate();
        IndexedInstanceStorage headInstances = workingMemory.get(headPredicate, true);
        modifiedInLastEvaluationRun.putIfAbsent(headPredicate, new LinkedHashSet<>());
        if (headInstances != null) {
            modifiedInLastEvaluationRun.get(headPredicate).addAll(headInstances.getAllInstances());
        }
        // Register positive body literal instances.
        for (Literal lit : rule.getPositiveBody()) {
            Predicate bodyPredicate = lit.getPredicate();
            IndexedInstanceStorage bodyInstances = workingMemory.get(bodyPredicate, true);
            modifiedInLastEvaluationRun.putIfAbsent(bodyPredicate, new LinkedHashSet<>());
            if (bodyInstances != null) {
                modifiedInLastEvaluationRun.get(bodyPredicate).addAll(bodyInstances.getAllInstances());
            }
        }
    }
}