Examples with AtomStoreImpl at.ac.tuwien.kr.alpha.core.common.AtomStoreImpl used on opensource projects

Example 11 with AtomStoreImpl

use of at.ac.tuwien.kr.alpha.core.common.AtomStoreImpl in project Alpha by alpha-asp.

the class LiteralInstantiationStrategyTest method defaultLazyGroundingCheckFalseGroundLiteral.

/**
 * Uses {@link DefaultLazyGroundingInstantiationStrategy} to check the truth
 * (i.e. {@link AssignmentStatus}) of the positive ground literal "p(a)".
 *
 * In this case, the instantiation strategy has an assignment where the atom
 * "p(a)" is assigned ThriceTruth.FALSE, so we expect the instantiation strategy
 * to determine that p(a) is FALSE. Since UNASSIGNED and FALSE atoms are
 * (potentially) stale in working memory, we expect the atom "p(a)" to be added
 * to the stale set by the instantiation strategy.
 */
@Test
public void defaultLazyGroundingCheckFalseGroundLiteral() {
    Predicate p = Predicates.getPredicate("p", 1);
    BasicAtom pOfA = Atoms.newBasicAtom(p, Terms.newSymbolicConstant("a"));
    WorkingMemory workingMemory = new WorkingMemory();
    AtomStore atomStore = new AtomStoreImpl();
    WritableAssignment assignment = new TrailAssignment(atomStore);
    atomStore.putIfAbsent(pOfA);
    assignment.growForMaxAtomId();
    assignment.assign(atomStore.get(pOfA), ThriceTruth.FALSE);
    LinkedHashSet<Atom> staleSet = new LinkedHashSet<>();
    DefaultLazyGroundingInstantiationStrategy strategy = new DefaultLazyGroundingInstantiationStrategy(workingMemory, atomStore, Collections.emptyMap(), false);
    strategy.setStaleWorkingMemoryEntries(staleSet);
    strategy.setCurrentAssignment(assignment);
    AssignmentStatus assignmentStatus = strategy.getTruthForGroundLiteral(Literals.fromAtom(pOfA, true));
    assertEquals(AssignmentStatus.FALSE, assignmentStatus);
    assertEquals(1, staleSet.size());
    assertTrue(staleSet.contains(pOfA));
}

Example 12 with AtomStoreImpl

use of at.ac.tuwien.kr.alpha.core.common.AtomStoreImpl in project Alpha by alpha-asp.

the class LiteralInstantiationStrategyTest method defaultLazyGroundingNoAssignmentSubstituteNonGroundLiteral.

/**
 * Uses {@link DefaultLazyGroundingInstantiationStrategy} to find ground
 * instances for the partially ground positive literal "q(a, X)".
 *
 * In this case, the instantiation strategy does not have an assignment set (as
 * is the case when {@link NaiveGrounder} is in bootstrap), so we expect the
 * assignment status (i.e. assignment status of the found ground instance)
 * passed back with the substitution to be TRUE. Furthermore, the stale atom set
 * (used by {@link NaiveGrounder} to clean up atoms that should be deleted from
 * working memory) must stay empty.
 */
@Test
public void defaultLazyGroundingNoAssignmentSubstituteNonGroundLiteral() {
    Predicate q = Predicates.getPredicate("q", 2);
    BasicAtom nonGroundAtom = Atoms.newBasicAtom(q, Terms.newSymbolicConstant("a"), Terms.newVariable("X"));
    WorkingMemory workingMemory = new WorkingMemory();
    workingMemory.initialize(q);
    workingMemory.addInstance(Atoms.newBasicAtom(q, Terms.newSymbolicConstant("a"), Terms.newSymbolicConstant("b")), true);
    LinkedHashSet<Atom> staleSet = new LinkedHashSet<>();
    DefaultLazyGroundingInstantiationStrategy strategy = new DefaultLazyGroundingInstantiationStrategy(workingMemory, new AtomStoreImpl(), Collections.emptyMap(), false);
    strategy.setStaleWorkingMemoryEntries(staleSet);
    strategy.setCurrentAssignment(null);
    List<ImmutablePair<Substitution, AssignmentStatus>> result = strategy.getAcceptedSubstitutions(Literals.fromAtom(nonGroundAtom, true), new BasicSubstitution());
    assertEquals(1, result.size());
    ImmutablePair<Substitution, AssignmentStatus> substitutionInfo = result.get(0);
    Substitution substitution = substitutionInfo.left;
    AssignmentStatus assignmentStatus = substitutionInfo.right;
    assertEquals(AssignmentStatus.TRUE, assignmentStatus);
    assertTrue(substitution.isVariableSet(Terms.newVariable("X")));
    assertEquals(Terms.newSymbolicConstant("b"), substitution.eval(Terms.newVariable("X")));
    assertTrue(staleSet.isEmpty());
}

Example 13 with AtomStoreImpl

use of at.ac.tuwien.kr.alpha.core.common.AtomStoreImpl in project Alpha by alpha-asp.

the class LiteralInstantiationStrategyTest method defaultLazyGroundingSubstituteNonGroundLiteralWithFalseInstance.

/**
 * Uses {@link DefaultLazyGroundingInstantiationStrategy} to find the ground
 * instance "q(a, b)" for the partially ground positive literal "q(a, X)".
 *
 * In this case, the instantiation strategy has an assignment where q(a, b) is
 * assigned ThriceTruth.FALSE, so we expect an empty list from
 * {@link LiteralInstantiationStrategy#getAcceptedSubstitutions(Literal, Substitution)}.
 * Furthermore, we expect the atom q(a, b) to be added to the stale atom set.
 */
@Test
public void defaultLazyGroundingSubstituteNonGroundLiteralWithFalseInstance() {
    Predicate q = Predicates.getPredicate("q", 2);
    BasicAtom nonGroundAtom = Atoms.newBasicAtom(q, Terms.newSymbolicConstant("a"), Terms.newVariable("X"));
    WorkingMemory workingMemory = new WorkingMemory();
    workingMemory.initialize(q);
    workingMemory.addInstance(Atoms.newBasicAtom(q, Terms.newSymbolicConstant("a"), Terms.newSymbolicConstant("b")), true);
    AtomStore atomStore = new AtomStoreImpl();
    WritableAssignment assignment = new TrailAssignment(atomStore);
    BasicAtom groundAtom = Atoms.newBasicAtom(q, Terms.newSymbolicConstant("a"), Terms.newSymbolicConstant("b"));
    atomStore.putIfAbsent(groundAtom);
    assignment.growForMaxAtomId();
    assignment.assign(atomStore.get(groundAtom), ThriceTruth.FALSE);
    LinkedHashSet<Atom> staleSet = new LinkedHashSet<>();
    DefaultLazyGroundingInstantiationStrategy strategy = new DefaultLazyGroundingInstantiationStrategy(workingMemory, atomStore, Collections.emptyMap(), false);
    strategy.setStaleWorkingMemoryEntries(staleSet);
    strategy.setCurrentAssignment(assignment);
    List<ImmutablePair<Substitution, AssignmentStatus>> result = strategy.getAcceptedSubstitutions(Literals.fromAtom(nonGroundAtom, true), new BasicSubstitution());
    assertTrue(result.isEmpty());
    assertEquals(1, staleSet.size());
    assertTrue(staleSet.contains(groundAtom));
}

Example 14 with AtomStoreImpl

use of at.ac.tuwien.kr.alpha.core.common.AtomStoreImpl in project Alpha by alpha-asp.

the class AlphaImpl method prepareSolverFor.

/**
 * Prepares a solver (and accompanying grounder) instance pre-loaded with the given program. Use this if the
 * solver is needed after reading answer sets (e.g. for obtaining statistics).
 *
 * @param program the program to solve.
 * @param filter  a (java util) predicate that filters (asp-)predicates which should be contained in the answer
 *                set stream from the solver.
 * @return a solver (and accompanying grounder) instance pre-loaded with the given program.
 */
private Solver prepareSolverFor(CompiledProgram program, java.util.function.Predicate<Predicate> filter) {
    String grounderName = config.getGrounderName();
    boolean doDebugChecks = config.isDebugInternalChecks();
    GrounderHeuristicsConfiguration grounderHeuristicConfiguration = GrounderHeuristicsConfiguration.getInstance(config.getGrounderToleranceConstraints(), config.getGrounderToleranceRules());
    grounderHeuristicConfiguration.setAccumulatorEnabled(config.isGrounderAccumulatorEnabled());
    AtomStore atomStore = new AtomStoreImpl();
    Grounder grounder = GrounderFactory.getInstance(grounderName, program, atomStore, filter, grounderHeuristicConfiguration, doDebugChecks);
    return SolverFactory.getInstance(config, atomStore, grounder);
}

Example 15 with AtomStoreImpl

use of at.ac.tuwien.kr.alpha.core.common.AtomStoreImpl in project Alpha by alpha-asp.

the class TestUtils method buildSolverFromSystemConfig.

private static Solver buildSolverFromSystemConfig(ASPCore2Program prog, SystemConfig cfg) {
    AtomStore atomStore = new AtomStoreImpl();
    NormalProgram normalProg = new NormalizeProgramTransformation(cfg.getAggregateRewritingConfig()).apply(prog);
    InternalProgram preprocessed = cfg.isEvaluateStratifiedPart() ? new StratifiedEvaluation().apply(AnalyzedProgram.analyzeNormalProgram(normalProg)) : InternalProgram.fromNormalProgram(normalProg);
    return SolverFactory.getInstance(cfg, atomStore, GrounderFactory.getInstance(cfg.getGrounderName(), preprocessed, atomStore, cfg.isDebugInternalChecks()));
}