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

Example 1 with Assignment

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

the class NaiveGrounderTest method testPermissiveGrounderHeuristicTolerance.

/**
 * Tests if {@link NaiveGrounder#getGroundInstantiations(InternalRule, RuleGroundingOrder, Substitution, Assignment)}
 * produces ground instantiations for the rule with ID {@code ruleID} in {@code program} when {@code startingLiteral}
 * unified with the numeric instance {@code startingInstance} is used as starting literal and the following
 * additional conditions are established:
 * <ul>
 * <li>The atoms {@code b([startingInstance], 1), ..., b([startingInstance], n)} are added to the grounder's
 * working memory without changing the assignment, where {@code arityOfB-1} occurences of {@code startingInstance}
 * are used instead of {@code [startingInstance]} and {@code n} is the length of the {@code truthsOfB} array.
 * For example, if the length of {@code truthsOfB} is 2 and {@code arityOfB} is also 2, these atoms are
 * {@code b(1,1), b(1,2)}.
 * </li>
 * <li>The same atoms are assigned the truth values in the {@code truthsOfB} array.</li>
 * </ul>
 * It is asserted that ground instantiations are produced if and only if {@code expectNoGoods} is true.
 * If ground instantiations are produced, it is also asserted that the numbers of unassigned positive body atoms
 * determined by {@code getGroundInstantiations} match those given in {@code expectedNumbersOfUnassignedPositiveBodyAtoms}.
 */
private void testPermissiveGrounderHeuristicTolerance(ASPCore2Program program, int ruleID, Literal startingLiteral, int startingInstance, int tolerance, ThriceTruth[] truthsOfB, int arityOfB, boolean expectNoGoods, List<Integer> expectedNumbersOfUnassignedPositiveBodyAtoms) {
    CompiledProgram internalPrg = InternalProgram.fromNormalProgram(NORMALIZE_TRANSFORM.apply(program));
    AtomStore atomStore = new AtomStoreImpl();
    TrailAssignment currentAssignment = new TrailAssignment(atomStore);
    GrounderHeuristicsConfiguration heuristicConfiguration = GrounderHeuristicsConfiguration.getInstance(tolerance, tolerance);
    NaiveGrounder grounder = (NaiveGrounder) GrounderFactory.getInstance("naive", internalPrg, atomStore, p -> true, heuristicConfiguration, true);
    int[] bAtomIDs = new int[truthsOfB.length];
    for (int i = 0; i < truthsOfB.length; i++) {
        int[] bTerms = new int[arityOfB];
        for (int n = 0; n < arityOfB; n++) {
            bTerms[n] = (n == arityOfB - 1) ? i + 1 : startingInstance;
        }
        bAtomIDs[i] = atomStore.putIfAbsent(atom("b", bTerms));
    }
    addAtomsToWorkingMemoryWithoutChangingTheAssignment(atomStore, grounder, bAtomIDs);
    assign(currentAssignment, bAtomIDs, truthsOfB);
    grounder.bootstrap();
    final CompiledRule nonGroundRule = grounder.getNonGroundRule(ruleID);
    final Substitution substStartingLiteral = BasicSubstitution.specializeSubstitution(startingLiteral, new Instance(Terms.newConstant(startingInstance)), BasicSubstitution.EMPTY_SUBSTITUTION);
    final BindingResult bindingResult = grounder.getGroundInstantiations(nonGroundRule, nonGroundRule.getGroundingInfo().orderStartingFrom(startingLiteral), substStartingLiteral, currentAssignment);
    assertEquals(expectNoGoods, bindingResult.size() > 0);
    if (bindingResult.size() > 0) {
        assertEquals(expectedNumbersOfUnassignedPositiveBodyAtoms, bindingResult.getNumbersOfUnassignedPositiveBodyAtoms());
    } else {
        assertTrue(bindingResult.getNumbersOfUnassignedPositiveBodyAtoms().isEmpty());
    }
}

Example 2 with Assignment

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

the class NaiveGrounderTest method testDeadEnd.

/**
 * Tests the method {@link NaiveGrounder#getGroundInstantiations(InternalRule, RuleGroundingOrder, Substitution, Assignment)} on a
 * predefined program:
 * <code>
 *  p1(1). q1(1). <br/>
 * 	x :- p1(X), p2(X), q1(Y), q2(Y). <br/>
 * 	p2(X) :- something(X). <br/>
 * 	q2(X) :- something(X). <br/>
 * </code>
 * Given one grounding order {@code groundingOrder} for the first rule in this program which starts with
 * the literal whose predicate name is {@code predicateNameOfStartingLiteral} and a substitution substituting
 * the variable in this literal by 1 it is attempted to ground the rule.
 * It is then asserted that ground instantiations are produced if and only if {@code expectNoGoods} is true.
 *
 * @param predicateNameOfStartingLiteral the predicate name of the starting literal, either "p1" or "q1".
 * @param groundingOrder                 a grounding order for the first rule in the predefined program that starts with the literal
 *                                       whose predicate name is {@code predicateNameOfStartingLiteral}.
 * @param expectNoGoods                  {@code true} iff ground instantiations are expected to be produced under the conditions
 *                                       described above.
 */
private void testDeadEnd(String predicateNameOfStartingLiteral, RuleGroundingOrderImpl groundingOrder, boolean expectNoGoods) {
    String aspStr = "p1(1). q1(1). " + "x :- p1(X), p2(X), q1(Y), q2(Y). " + "p2(X) :- something(X). " + "q2(X) :- something(X). ";
    CompiledProgram program = InternalProgram.fromNormalProgram(NORMALIZE_TRANSFORM.apply(PROGRAM_PARSER.parse(aspStr)));
    AtomStore atomStore = new AtomStoreImpl();
    NaiveGrounder grounder = (NaiveGrounder) GrounderFactory.getInstance("naive", program, atomStore, p -> true, GrounderHeuristicsConfiguration.permissive(), true);
    CompiledRule nonGroundRule = grounder.getNonGroundRule(0);
    String strLiteral = "p1".equals(predicateNameOfStartingLiteral) ? "p1(X)" : "p1(Y)";
    final Literal startingLiteral = PROGRAM_PART_PARSER.parseLiteral(strLiteral);
    ((RuleGroundingInfoImpl) nonGroundRule.getGroundingInfo()).groundingOrders.put(startingLiteral, groundingOrder);
    grounder.bootstrap();
    TrailAssignment currentAssignment = new TrailAssignment(atomStore);
    final Substitution subst1 = BasicSubstitution.specializeSubstitution(startingLiteral, new Instance(Terms.newConstant(1)), BasicSubstitution.EMPTY_SUBSTITUTION);
    final BindingResult bindingResult = grounder.getGroundInstantiations(nonGroundRule, groundingOrder, subst1, currentAssignment);
    assertEquals(expectNoGoods, bindingResult.size() > 0);
}

Example 3 with Assignment

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

the class NaiveGrounderTest method testIfGrounderGroundsRule.

/**
 * Tests if {@link NaiveGrounder#getGroundInstantiations(InternalRule, RuleGroundingOrder, Substitution, Assignment)}
 * produces ground instantiations for the rule with ID {@code ruleID} in {@code program} when {@code startingLiteral}
 * unified with the numeric instance {@code startingInstance} is used as starting literal and {@code b(1)} is assigned
 * {@code bTruth}.
 * It is asserted that ground instantiations are produced if and only if {@code expectNoGoods} is true.
 */
private void testIfGrounderGroundsRule(ASPCore2Program program, int ruleID, Literal startingLiteral, int startingInstance, ThriceTruth bTruth, boolean expectNoGoods) {
    CompiledProgram internalPrg = InternalProgram.fromNormalProgram(NORMALIZE_TRANSFORM.apply(program));
    AtomStore atomStore = new AtomStoreImpl();
    TrailAssignment currentAssignment = new TrailAssignment(atomStore);
    NaiveGrounder grounder = (NaiveGrounder) GrounderFactory.getInstance("naive", internalPrg, atomStore, p -> true, GrounderHeuristicsConfiguration.permissive(), true);
    int b = atomStore.putIfAbsent(atom("b", 1));
    currentAssignment.growForMaxAtomId();
    currentAssignment.assign(b, bTruth);
    grounder.bootstrap();
    final CompiledRule nonGroundRule = grounder.getNonGroundRule(ruleID);
    final Substitution substStartingLiteral = BasicSubstitution.specializeSubstitution(startingLiteral, new Instance(Terms.newConstant(startingInstance)), BasicSubstitution.EMPTY_SUBSTITUTION);
    final BindingResult bindingResult = grounder.getGroundInstantiations(nonGroundRule, nonGroundRule.getGroundingInfo().orderStartingFrom(startingLiteral), substStartingLiteral, currentAssignment);
    assertEquals(expectNoGoods, bindingResult.size() > 0);
}