/**
* Copyright 2004-2016 Riccardo Solmi. All rights reserved.
* This file is part of the Whole Platform.
*
* The Whole Platform is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* The Whole Platform 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 the Whole Platform. If not, see <http://www.gnu.org/licenses/>.
*/
package org.whole.lang.iterators;
import org.whole.lang.bindings.IBindingScope;
import org.whole.lang.bindings.NullScope;
import org.whole.lang.model.IEntity;
/**
* @author Riccardo Solmi
*/
public class ChildReverseIterator<E extends IEntity> extends AbstractCloneableIterator<E> {
protected IEntity entity; //parent
protected int nextIndex; //zero relative
private int firstIndex;
private int lastIndex = -1;
protected ChildReverseIterator() {
this(Integer.MAX_VALUE);
}
protected ChildReverseIterator(int firstIndex) {
this.firstIndex = firstIndex;
}
public IBindingScope lookaheadScope() {
return NullScope.instance;
}
public boolean hasNext() {
return entity != null && nextIndex >= 0;
}
@SuppressWarnings("unchecked")
public E next() {
return (E) entity.wGet(lastIndex = nextIndex--);
}
@SuppressWarnings("unchecked")
public E lookahead() {
try {
return (E) entity.wGet(nextIndex);
} catch (IndexOutOfBoundsException e) {
return null;
} catch (NullPointerException e) {
return null;
}
}
public void reset(IEntity entity) {
this.entity = entity;
nextIndex = firstIndex != Integer.MAX_VALUE ? firstIndex : entity != null ? entity.wSize()-1 : -1;
lastIndex = -1;
}
public void prune() {
}
public int nextIndex() {
return nextIndex;
}
public void set(E value) {
if (lastIndex == -1)
throw new IllegalStateException();
entity.wSet(lastIndex, value);
}
public void add(E value) {
if (lastIndex == -1)
throw new IllegalStateException();
entity.wAdd(lastIndex+1, value);
}
public void remove() {
if (lastIndex == -1)
throw new IllegalStateException();
entity.wRemove(lastIndex);
lastIndex = -1;
}
}