PointwiseUpdateIterator.java

/**
 * 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.queries.iterators;

import org.whole.lang.bindings.BindingManagerFactory;
import org.whole.lang.iterators.IEntityIterator;
import org.whole.lang.model.IEntity;
import org.whole.lang.util.EntityUtils;

/**
 * @author Riccardo Solmi
 */
public class PointwiseUpdateIterator<E extends IEntity> extends AbstractPointwiseIterator<E> {
	protected PointwiseUpdateIterator(IEntityIterator<E> valuesIterator, IEntityIterator<? super E> toIterator) {
		super(valuesIterator, toIterator);
	}

	@SuppressWarnings("unchecked")
	protected E doLookahead(IEntity toLookahead, E nextEntity) {
		return (E) EntityUtils.convertCloneIfParented(nextEntity, EntityUtils.getFormalType(toLookahead));
	}

	protected void doNext(IEntity toEntity, E nextEntity) {
		if (BindingManagerFactory.instance.isVoid(nextEntity))
			return;

		toIterator.set(EntityUtils.cloneIfParented(nextEntity));
	}

    @Override
	public void toString(StringBuilder sb) {
    	sb.append("update(");
    	sb.append(toIterator.toString());
    	sb.append(" .= ");
    	super.toString(sb);
    	sb.append(")");
    }
}