org.eclipse.viatra2.gtasm.patternmatcher.impl/src/org/eclipse/viatra2/gtasm/patternmatcher/impl/patternmatcher/internal/callgraph/PatternVariantIterator.java

/*******************************************************************************
 * Copyright (c) 2004-2008 Akos Horvath, Gergely Varro and Daniel Varro
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *    Akos Horvath, Gergely Varro - initial API and implementation
 *******************************************************************************/

 package org.eclipse.viatra2.gtasm.patternmatcher.impl.patternmatcher.internal.callgraph;

import java.util.Iterator;
import java.util.LinkedList;
import java.util.List;
import java.util.NoSuchElementException;


public class PatternVariantIterator implements Iterator<List<IFlattenedPatternElement>> {
    private PatternNode root;
    private LinkedList<IFlattenedPatternElement> solution;
    private boolean hasNext;

    public PatternVariantIterator(PatternNode root) {
        this.root = root;
        this.solution = new LinkedList<IFlattenedPatternElement>();
        this.hasNext = (root.isRoot() ? root.traverse(this) : false);
    }
    
    void addLast(IFlattenedPatternElement element) {
        solution.addLast(element);
    }
    
    void removeLast() {
        solution.removeLast();
    }
    
    public boolean hasNext() {
        return hasNext;
    }

    public List<IFlattenedPatternElement> next() {
        if (hasNext) {
            List<IFlattenedPatternElement> result = new LinkedList<IFlattenedPatternElement>(solution);
            hasNext = root.traverse(this);
            return result;
        } else {
            throw new NoSuchElementException();
        }
    }

    public void remove() {
        throw new UnsupportedOperationException();
    }
}