Examples with AbstractVoidVisitor kodkod.ast.visitor.AbstractVoidVisitor used on opensource projects

Example 1 with AbstractVoidVisitor

use of kodkod.ast.visitor.AbstractVoidVisitor in project org.alloytools.alloy by AlloyTools.

the class ResolutionBasedProof method connectedCore.

/**
 * Returns the connected core based on the given set of core variables.
 *
 * @requires coreVar = StrategyUtils.coreVars(solver.proof());
 * @return let formulas = (this.log.records[int] & literal.{i: int | abs(i) in
 *         coreVars}).formula | connected = {f: formulas | some s: set coreNodes
 *         | f + this.log.formula in s and (s - this.log.formula).~components in
 *         s }
 */
private Set<Formula> connectedCore(final IntSet coreVars) {
    final Set<Formula> coreNodes = new IdentityHashSet<Formula>();
    final RecordFilter filter = new RecordFilter() {

        @Override
        public boolean accept(Node node, Formula translated, int literal, Map<Variable, TupleSet> env) {
            return coreVars.contains(StrictMath.abs(literal));
        }
    };
    for (Iterator<TranslationRecord> itr = log().replay(filter); itr.hasNext(); ) {
        coreNodes.add(itr.next().translated());
    }
    final Set<Formula> connected = new IdentityHashSet<Formula>();
    final AbstractVoidVisitor traverser = new AbstractVoidVisitor() {

        final Set<Node> visited = new IdentityHashSet<Node>();

        /**
         * Returns true if the given node has been visited before or if it is not
         * contained in this.nodes set. Otherwise adds the node to the connected set and
         * returns false.
         *
         * @ensures this.visited' = this.visited + n
         * @ensures n !in this.visited && n in coreNodes => connected' = connected + n
         *          else connected' = connected
         * @return n in visited || n !in coreNodes
         */
        @Override
        protected boolean visited(Node n) {
            if (visited.add(n) && coreNodes.contains(n)) {
                connected.add((Formula) n);
                return false;
            }
            return true;
        }
    };
    for (Formula root : log().roots()) {
        root.accept(traverser);
    }
    return connected;
}

Example 2 with AbstractVoidVisitor

use of kodkod.ast.visitor.AbstractVoidVisitor in project org.alloytools.alloy by AlloyTools.

the class Nodes method minRoots.

/**
 * Returns a minimal subset of {@linkplain #roots(Formula) roots} of the given
 * formula such that all nodes in the given collection are reachable from those
 * roots. The returned subset is a local minimum in that none of its members can
 * be removed without leaving some node in the descendants set unreachable from
 * the remaining roots.
 *
 * @requires descendants in formula.*components
 * @return { s: Set<Formula> | s.elements in roots(formula) and descendants in
 *         s.elements.*components and no s': Set<Formula> | s.containsAll(s')
 *         and s'.size()<s.size() and descendants in s.elements.*components }
 * @throws IllegalArgumentException descendants !in formula.*components
 */
public static Set<Formula> minRoots(Formula formula, Collection<? extends Node> descendants) {
    final Set<Node> desc = new IdentityHashSet<Node>(descendants);
    final VoidVisitor visitor = new AbstractVoidVisitor() {

        final Set<Node> visited = new IdentityHashSet<Node>();

        @Override
        protected boolean visited(Node n) {
            if (visited.add(n)) {
                desc.remove(n);
                return false;
            }
            return true;
        }
    };
    final Set<Formula> roots = new LinkedHashSet<Formula>();
    for (Formula root : roots(formula)) {
        final int size = desc.size();
        root.accept(visitor);
        if (desc.size() < size) {
            roots.add(root);
        }
        if (desc.isEmpty()) {
            break;
        }
    }
    if (!desc.isEmpty())
        throw new IllegalArgumentException("descendants !in formula.*components: formula=" + formula + " ; descendants=" + descendants);
    return roots;
}

Example 3 with AbstractVoidVisitor

use of kodkod.ast.visitor.AbstractVoidVisitor in project org.alloytools.alloy by AlloyTools.

the class AnnotatedNode method relations.

/**
 * Returns the set of all relations at the leaves of this annotated node.
 *
 * @return Relation & this.node.*components
 */
public final Set<Relation> relations() {
    final Set<Relation> relations = new IdentityHashSet<Relation>();
    final AbstractVoidVisitor visitor = new AbstractVoidVisitor() {

        private final Set<Node> visited = new IdentityHashSet<Node>(sharedNodes.size());

        @Override
        protected boolean visited(Node n) {
            return sharedNodes.contains(n) && !visited.add(n);
        }

        @Override
        public void visit(Relation relation) {
            relations.add(relation);
        }
    };
    node.accept(visitor);
    return relations;
}