net.automatalib.util.ts.traversal.BFSOrderIterator Maven / Gradle / Ivy
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This artifact provides various common utility operations for analyzing and manipulating
automata and graphs, such as traversal, minimization and copying.
/* Copyright (C) 2013 TU Dortmund
* This file is part of AutomataLib, http://www.automatalib.net/.
*
* AutomataLib is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License version 3.0 as published by the Free Software Foundation.
*
* AutomataLib is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with AutomataLib; if not, see
* http://www.gnu.de/documents/lgpl.en.html.
*/
package net.automatalib.util.ts.traversal;
import java.util.ArrayDeque;
import java.util.Collection;
import java.util.Iterator;
import java.util.Queue;
import net.automatalib.commons.util.mappings.MutableMapping;
import net.automatalib.ts.simple.SimpleTS;
import net.automatalib.util.traversal.VisitedState;
public class BFSOrderIterator implements Iterator {
private final Collection inputs;
private final SimpleTS ts;
private final Queue bfsQueue = new ArrayDeque();
private final MutableMapping seen;
public BFSOrderIterator(SimpleTS ts, Collection inputs) {
this.ts = ts;
this.inputs = inputs;
Collection initial = ts.getInitialStates();
bfsQueue.addAll(initial);
seen = ts.createStaticStateMapping();
for(S state : initial)
seen.put(state, VisitedState.VISITED);
}
/*
* (non-Javadoc)
* @see java.util.Iterator#hasNext()
*/
@Override
public boolean hasNext() {
return !bfsQueue.isEmpty();
}
/*
* (non-Javadoc)
* @see java.util.Iterator#next()
*/
@Override
public S next() {
S state = bfsQueue.poll();
for(I input : inputs) {
Collection succs = ts.getSuccessors(state, input);
for(S succ : succs) {
if(seen.put(succ, VisitedState.VISITED) != VisitedState.VISITED)
bfsQueue.add(succ);
}
}
return state;
}
/*
* (non-Javadoc)
* @see java.util.Iterator#remove()
*/
@Override
public void remove() {
throw new UnsupportedOperationException();
}
}