Examples with TrailAssignment at.ac.tuwien.kr.alpha.core.solver.TrailAssignment used on opensource projects

Example 16 with TrailAssignment

use of at.ac.tuwien.kr.alpha.core.solver.TrailAssignment in project Alpha by alpha-asp.

the class LiteralInstantiationStrategyTest method defaultLazyGroundingSubstituteNonGroundLiteralWithUnassignedInstance.

/**
 * 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 empty assignment, so we
 * expect the assignment status (i.e. assignment status of the found ground
 * instance) passed back with the substitution to be UNASSIGNED. Since
 * UNASSIGNED and FALSE atoms are (potentially) stale in working memory, we
 * expect the atom "q(a, b)" to be added to the stale set by the instantiation
 * strategy.
 */
@Test
public void defaultLazyGroundingSubstituteNonGroundLiteralWithUnassignedInstance() {
    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);
    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());
    assertEquals(1, result.size());
    ImmutablePair<Substitution, AssignmentStatus> substitutionInfo = result.get(0);
    Substitution substitution = substitutionInfo.left;
    AssignmentStatus assignmentStatus = substitutionInfo.right;
    assertEquals(AssignmentStatus.UNASSIGNED, assignmentStatus);
    assertTrue(substitution.isVariableSet(Terms.newVariable("X")));
    assertEquals(Terms.newSymbolicConstant("b"), substitution.eval(Terms.newVariable("X")));
    assertEquals(1, staleSet.size());
    assertTrue(staleSet.contains(Atoms.newBasicAtom(q, Terms.newSymbolicConstant("a"), Terms.newSymbolicConstant("b"))));
}

Example 17 with TrailAssignment

use of at.ac.tuwien.kr.alpha.core.solver.TrailAssignment in project Alpha by alpha-asp.

the class AlphaHeuristicTestAssumptions method setUp.

@BeforeEach
public void setUp() {
    String testProgram = "" + "b1." + "b2." + "{b3}." + "{b4}." + "h :- b1, b2, not b3, not b4.";
    CompiledProgram internalProgram = parseAndPreprocess.apply(testProgram);
    atomStore = new AtomStoreImpl();
    grounder = new NaiveGrounder(internalProgram, atomStore, true);
    assignment = new TrailAssignment(atomStore);
    choiceManager = new TestableChoiceManager(assignment, new NaiveNoGoodStore(assignment));
}

Example 18 with TrailAssignment

use of at.ac.tuwien.kr.alpha.core.solver.TrailAssignment in project Alpha by alpha-asp.

the class BranchingHeuristicFactoryTest method setUp.

@BeforeEach
public void setUp() {
    AtomStore atomStore = new AtomStoreImpl();
    WritableAssignment assignment = new TrailAssignment(atomStore);
    NoGoodStore store = new NoGoodStoreAlphaRoaming(assignment, debugInternalChecks);
    this.choiceManager = new ChoiceManager(assignment, store);
}

Example 19 with TrailAssignment

use of at.ac.tuwien.kr.alpha.core.solver.TrailAssignment in project Alpha by alpha-asp.

the class ReplayHeuristicTest method setUp.

@BeforeEach
public void setUp() {
    AtomStore atomStore = new AtomStoreImpl();
    WritableAssignment assignment = new TrailAssignment(atomStore);
    NoGoodStore store = new NoGoodStoreAlphaRoaming(assignment, debugInternalChecks);
    this.choiceManager = new PseudoChoiceManager(assignment, store);
}

Example 20 with TrailAssignment

use of at.ac.tuwien.kr.alpha.core.solver.TrailAssignment in project Alpha by alpha-asp.

the class NaiveGrounderTest method groundRuleAlreadyGround.

/**
 * Asserts that a ground rule whose positive body is not satisfied by the empty assignment
 * is grounded immediately.
 */
@Test
public void groundRuleAlreadyGround() {
    ASPCore2Program program = PROGRAM_PARSER.parse("a :- not b. " + "b :- not a. " + "c :- b.");
    NormalProgram normal = NORMALIZE_TRANSFORM.apply(program);
    CompiledProgram prog = new StratifiedEvaluation().apply(AnalyzedProgram.analyzeNormalProgram(normal));
    AtomStore atomStore = new AtomStoreImpl();
    Grounder grounder = GrounderFactory.getInstance("naive", prog, atomStore, true);
    Map<Integer, NoGood> noGoods = grounder.getNoGoods(new TrailAssignment(atomStore));
    int litCNeg = Literals.atomToLiteral(atomStore.get(PROGRAM_PART_PARSER.parseBasicAtom("c")), false);
    int litB = Literals.atomToLiteral(atomStore.get(PROGRAM_PART_PARSER.parseBasicAtom("b")));
    assertExistsNoGoodContaining(noGoods.values(), litCNeg);
    assertExistsNoGoodContaining(noGoods.values(), litB);
}