Examples with IntSet kodkod.util.ints.IntSet used on opensource projects

Example 36 with IntSet

use of kodkod.util.ints.IntSet in project org.alloytools.alloy by AlloyTools.

the class HybridStrategy method next.

/**
 * {@inheritDoc}
 *
 * @see kodkod.engine.satlab.ReductionStrategy#next(kodkod.engine.satlab.ResolutionTrace)
 */
@Override
public IntSet next(ResolutionTrace trace) {
    if (topVars.isEmpty())
        // tried everything
        return Ints.EMPTY_SET;
    final IntSet core = trace.core();
    for (Iterator<Clause> iter = trace.iterator(core); iter.hasNext(); ) {
        Clause clause = iter.next();
        int maxVar = clause.maxVariable();
        if (topVars.remove(maxVar)) {
            // get all core clauses with the given maximum variable
            IntSet exclude = coreClausesWithMaxVar(trace, maxVar);
            assert !exclude.isEmpty();
            // get all clauses reachable from the conflict clause
            IntSet next = trace.reachable(Ints.singleton(trace.size() - 1));
            // remove all clauses backward reachable from the clauses with
            // the given maxVar
            next.removeAll(trace.backwardReachable(exclude));
            if (!next.isEmpty()) {
                return next;
            }
        }
    }
    topVars.clear();
    return Ints.EMPTY_SET;
}

Example 37 with IntSet

use of kodkod.util.ints.IntSet in project org.alloytools.alloy by AlloyTools.

the class HybridStrategy method coreClausesWithMaxVar.

/**
 * Returns the indices of the clauses in the unsatisfiable core of the given
 * trace that have the specified maximum variable.
 *
 * @return { i: trace.core() | trace[i].maxVariable() = maxVariable }
 */
private static IntSet coreClausesWithMaxVar(ResolutionTrace trace, int maxVariable) {
    final IntSet core = trace.core();
    final IntSet restricted = new IntBitSet(core.max() + 1);
    final Iterator<Clause> clauses = trace.iterator(core);
    final IntIterator indices = core.iterator();
    while (clauses.hasNext()) {
        Clause clause = clauses.next();
        int index = indices.next();
        if (clause.maxVariable() == maxVariable)
            restricted.add(index);
    }
    return restricted;
}

Example 38 with IntSet

use of kodkod.util.ints.IntSet in project org.alloytools.alloy by AlloyTools.

the class NCEStrategy method next.

/**
 * {@inheritDoc}
 *
 * @see kodkod.engine.satlab.ReductionStrategy#next(kodkod.engine.satlab.ResolutionTrace)
 */
@Override
public IntSet next(ResolutionTrace trace) {
    if (varsToTry.isEmpty())
        return Ints.EMPTY_SET;
    // if the last attempt at reduction was unsuccessful,
    // add the unit clauses that we tried to discard back to coreVars
    coreVars.addAll(StrategyUtils.coreTailUnits(trace));
    // varsToTry.min();
    final int first = varsToTry.iterator().next();
    varsToTry.remove(first);
    coreVars.remove(first);
    // get all axioms corresponding to the clauses that
    // form the translations of formulas identified by coreVars
    final IntSet relevantClauses = StrategyUtils.clausesFor(trace, coreVars);
    assert !relevantClauses.isEmpty() && !relevantClauses.contains(trace.size() - 1);
    return relevantClauses;
}

Example 39 with IntSet

use of kodkod.util.ints.IntSet in project org.alloytools.alloy by AlloyTools.

the class TupleSet method project.

/**
 * Projects this TupleSet onto the given dimension.
 *
 * @return {s: TupleSet | s.arity = 1 && s.universe = this.universe && s.tuples
 *         = { t: Tuple | some q: this.tuples | q.atoms[dimension] =
 *         t.atoms[int] } }
 * @throws IllegalArgumentException dimension < 0 || dimension >= this.arity
 */
public TupleSet project(int dimension) {
    if (dimension < 0 || dimension >= arity) {
        throw new IllegalArgumentException("dimension < 0 || dimension >= this.arity");
    }
    final IntSet projection = Ints.bestSet(universe.size());
    final TupleFactory factory = universe.factory();
    for (IntIterator indexIter = tuples.iterator(); indexIter.hasNext(); ) {
        projection.add(factory.project(indexIter.next(), arity, dimension));
    }
    return new TupleSet(universe, 1, projection);
}

Example 40 with IntSet

use of kodkod.util.ints.IntSet in project org.alloytools.alloy by AlloyTools.

the class LazyTrace method reachable.

/**
 * Returns the indices of all clauses in the given trace that are reachable from
 * the conflict clause through the resolvents in trace[roots..trace.length-1].
 * This method assumes that that the last trace[roots..trace.length-1] clauses
 * encode resolvents as specified by the {@linkplain #LazyTrace(int[][], int)}
 * constructor.
 *
 * @return indices of all clauses in the given trace that are reachable from the
 *         conflict clause through the resolvents in
 *         trace[roots..trace.length-1]
 */
private static IntSet reachable(int[][] trace, int roots) {
    final IntSet reachable = new IntBitSet(trace.length);
    reachable.add(trace.length - 1);
    for (int i = trace.length - 1; i >= roots; i--) {
        if (reachable.contains(i)) {
            int[] resolvent = trace[i];
            for (int j = 0; j < resolvent.length; j++) {
                reachable.add(resolvent[j]);
            }
        }
    }
    return reachable;
}