org.sosy_lab.java_smt.api.visitors.TraversalProcess.java Source code

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Here is the source code for org.sosy_lab.java_smt.api.visitors.TraversalProcess.java

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/*
 *  JavaSMT is an API wrapper for a collection of SMT solvers.
 *  This file is part of JavaSMT.
 *
 *  Copyright (C) 2007-2016  Dirk Beyer
 *  All rights reserved.
 *
 *  Licensed under the Apache License, Version 2.0 (the "License");
 *  you may not use this file except in compliance with the License.
 *  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 */
package org.sosy_lab.java_smt.api.visitors;

import com.google.common.collect.ImmutableSet;
import org.sosy_lab.java_smt.api.BooleanFormulaManager;
import org.sosy_lab.java_smt.api.Formula;
import org.sosy_lab.java_smt.api.FormulaManager;

/**
 * Return class that lets the visitor guide the recursive formula traversal process started with
 * {@link FormulaManager#visitRecursively}. or {@link BooleanFormulaManager#visitRecursively}.
 */
public class TraversalProcess {
    /** Continue traversal and recurse into current formula subtree. */
    public static final TraversalProcess CONTINUE = new TraversalProcess(TraversalType.CONTINUE_TYPE,
            ImmutableSet.of());

    /** Continue traversal, but do not recurse into current formula subtree. */
    public static final TraversalProcess SKIP = new TraversalProcess(TraversalType.SKIP_TYPE, ImmutableSet.of());

    /** Immediately abort traversal and return to caller. */
    public static final TraversalProcess ABORT = new TraversalProcess(TraversalType.ABORT_TYPE, ImmutableSet.of());

    /**
     * Traverse only the given children.
     *
     * <p>NOTE: given formulas which are <em>not</em> children of the given node will be ignored.
     */
    public static TraversalProcess custom(Iterable<? extends Formula> pToTraverse) {
        return new TraversalProcess(TraversalType.CUSTOM_TYPE, ImmutableSet.copyOf(pToTraverse));
    }

    /**
     * Traverse only the given child.
     *
     * <p>NOTE: any given which is <em>not</em> child of the given node will be ignored.
     */
    public static TraversalProcess custom(Formula pToTraverse) {
        return new TraversalProcess(TraversalType.CUSTOM_TYPE, ImmutableSet.of(pToTraverse));
    }

    public enum TraversalType {
        CONTINUE_TYPE, SKIP_TYPE, ABORT_TYPE, CUSTOM_TYPE
    }

    private final TraversalType type;
    private final ImmutableSet<? extends Formula> toTraverse;

    private TraversalProcess(TraversalType pType, ImmutableSet<? extends Formula> pToTraverse) {
        type = pType;
        toTraverse = pToTraverse;
    }

    public TraversalType getType() {
        return type;
    }

    public boolean contains(Formula f) {
        if (type == TraversalType.CONTINUE_TYPE) {
            return true;
        } else if (type == TraversalType.SKIP_TYPE || type == TraversalType.ABORT_TYPE) {
            return false;
        } else {
            assert type == TraversalType.CUSTOM_TYPE;
            return toTraverse.contains(f);
        }
    }
}