net.automatalib.util.graphs.traversal.SimpleDFRecord Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of automata-util Show documentation

This artifact provides various common utility operations for analyzing and manipulating automata and graphs, such as traversal, minimization and copying.

There is a newer version: 0.11.0

Show newest version

/* Copyright (C) 2013-2019 TU Dortmund
 * This file is part of AutomataLib, http://www.automatalib.net/.
 *
 * 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 net.automatalib.util.graphs.traversal;

import java.util.Collection;
import java.util.Iterator;

import net.automatalib.graphs.IndefiniteGraph;

class SimpleDFRecord {

    public final N node;

    private Iterator edgeIterator;

    SimpleDFRecord(N node) {
        this.node = node;
    }

    public final boolean wasStarted() {
        return (edgeIterator != null);
    }

    public final boolean start(IndefiniteGraph graph) {
        if (edgeIterator != null) {
            return false;
        }
        Collection outEdges = graph.getOutgoingEdges(node);
        this.edgeIterator = outEdges.iterator();
        return true;
    }

    public final boolean hasNextEdge() {
        if (edgeIterator == null) {
            throw new IllegalStateException("Edge iteration not yet started");
        }
        return edgeIterator.hasNext();
    }

    public final E nextEdge() {
        if (edgeIterator == null) {
            throw new IllegalStateException("Edge iteration not yet started");
        }
        return edgeIterator.next();
    }

}