/*
 * Zorbage: an algebraic data hierarchy for use in numeric processing.
 *
 * Copyright (C) 2016-2019 Barry DeZonia
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 * 
 * 1. Redistributions of source code must retain the above copyright notice,
 *    this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 *    this list of conditions and the following disclaimer in the documentation
 *    and/or other materials provided with the distribution.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */
package nom.bdezonia.zorbage.procedure.impl.oob;

import nom.bdezonia.zorbage.procedure.Procedure2;
import nom.bdezonia.zorbage.type.algebra.Algebra;
import nom.bdezonia.zorbage.type.storage.datasource.IndexedDataSource;

/**
 * 
 * @author Barry DeZonia
 *
 */
public class MirrorOOB<T extends Algebra<T,U>, U> implements Procedure2<Long,U> {

	private final IndexedDataSource<U> a;
	private final long length;

	/**
	 * 
	 * @param a
	 */
	public MirrorOOB(IndexedDataSource<U> a) {
		this.a = a;
		this.length = a.size();
	}

	@Override
	public void call(Long i, U value) {
		long idx = i / length;
		if (i < 0) {
			long offset = ((-i) - 1) % length;
			if (idx % 2 == 0) {
				a.get(offset, value);
			}
			else {
				a.get(length - offset - 1, value);
			}
		}
		else if (i >= length) {
			long offset = i % length;
			if (idx % 2 == 0) {
				a.get(offset, value);
			}
			else {
				a.get(length - offset - 1, value);
			}
		}
		else
			throw new IllegalArgumentException("OOB method called with in bounds index");
	}

}

/*
 * Zorbage: an algebraic data hierarchy for use in numeric processing.
 *
 * Copyright (C) 2016-2019 Barry DeZonia
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 * 
 * 1. Redistributions of source code must retain the above copyright notice,
 *    this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 *    this list of conditions and the following disclaimer in the documentation
 *    and/or other materials provided with the distribution.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */
package nom.bdezonia.zorbage.procedure.impl.oob;

import nom.bdezonia.zorbage.procedure.Procedure2;
import nom.bdezonia.zorbage.type.algebra.Algebra;
import nom.bdezonia.zorbage.type.storage.datasource.IndexedDataSource;

/**
 * 
 * @author Barry DeZonia
 *
 */
public class MirrorOOB<T extends Algebra<T,U>, U> implements Procedure2<Long,U> {

	private final IndexedDataSource<U> a;
	private final long length;

	/**
	 * 
	 * @param a
	 */
	public MirrorOOB(IndexedDataSource<U> a) {
		this.a = a;
		this.length = a.size();
	}

	@Override
	public void call(Long i, U value) {
		long idx = i / length;
		if (i < 0) {
			long offset = ((-i) - 1) % length;
			if (idx % 2 == 0) {
				a.get(offset, value);
			}
			else {
				a.get(length - 1 - offset, value);
			}
		}
		else if (i >= length) {
			long offset = i % length;
			if (idx % 2 == 0) {
				a.get(offset, value);
			}
			else {
				a.get(length - 1 - offset, value);
			}
		}
		else
			throw new IllegalArgumentException("OOB method called with in bounds index");
	}

}

Make some code more clear