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/*
 * Copyright (c) 2017, Numdata BV, The Netherlands.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *     * 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.
 *     * Neither the name of Numdata nor the
 *       names of its contributors may be used to endorse or promote products
 *       derived from this software without specific prior written permission.
 *
 * 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 NUMDATA BV 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 com.numdata.oss;

import java.io.*;
import java.lang.reflect.*;
import java.util.*;

import org.jetbrains.annotations.*;

/**
 * This class contains utility methods for working with arrays. It offers some
 * of the essential functions of the {@link List} interface, handles {@code
 * null} values and can work on real arrays as well as {@link List} instances.
 *
 * @author Peter S. Heijnen
 */
@SuppressWarnings( { "ChainOfInstanceofChecks", "ObjectEquality" } )
public final class ArrayTools
{
	/**
	 * Utility class is not supposed to be instantiated.
	 */
	private ArrayTools()
	{
	}

	/**
	 * Check if the specified argument is {@code null}, an array, or a {@link
	 * List} instance. If not, generate a {@link IllegalArgumentException}.
	 *
	 * @param array Array or {@link List} to check.
	 *
	 * @throws IllegalArgumentException if {@code array} is not an array or
	 * list.
	 */
	private static void checkType( @Nullable final Object array )
	{
		if ( ( array != null ) && !isValidType( array ) )
		{
			throw new IllegalArgumentException( "not array or list" );
		}
	}

	/**
	 * Check if the specified argument is an array.
	 *
	 * @param object Object to check.
	 *
	 * @return {@code true} if the {@code object} argument is an array; {@code
	 * false} otherwise.
	 */
	public static boolean isArray( final Object object )
	{
		final boolean result;

		if ( object == null )
		{
			result = false;
		}
		else
		{
			final Class arrayClass = object.getClass();
			result = arrayClass.isArray();
		}

		return result;
	}

	/**
	 * Check if the specified argument is an array or a {@link List} instance.
	 *
	 * @param object Object to check.
	 *
	 * @return {@code true} if the {@code object} argument is an array or a
	 * {@link List} instance; {@code false} otherwise.
	 */
	public static boolean isValidType( final Object object )
	{
		return ( object instanceof List ) || isArray( object );
	}

	/**
	 * Clear contents of an array. This will reset all elements of an array to
	 * their default value ({@code 0}, {@code false}, {@code null}). If the
	 * array is {@code null} or has no elements, calling this method has no
	 * effect.
	 *
	 * IMPORTANT: The size of a {@link List} remains constant.
	 *
	 * @param array Array or {@link List} whose contents should be cleared.
	 */
	public static void clear( final Object array )
	{
		clear( array, 0, -1 );
	}

	/**
	 * Clear contents of an array starting in a specific range. This will reset
	 * all elements of an array in the specific range to their default value
	 * ({@code 0}, {@code false}, {@code null}). If the array is {@code null} or
	 * has no elements in the specified range, then calling this method has no
	 * effect.
	 *
	 * IMPORTANT: The size of a {@link List} remains constant.
	 *
	 * @param array      Array or {@link List} whose contents should be
	 *                   cleared.
	 * @param startIndex Index of first element to clear.
	 * @param endIndex   Index of element after last cleared element
	 *                   (out-of-range => use array length, e.g. -1).
	 *
	 * @throws ArrayIndexOutOfBoundsException if {@code startIndex} is
	 * negative.
	 * @throws IllegalArgumentException if {@code array} is not an array or
	 * list.
	 */
	public static void clear( final Object array, final int startIndex, final int endIndex )
	{
		checkType( array );

		if ( startIndex < 0 )
		{
			throw new ArrayIndexOutOfBoundsException( startIndex );
		}

		int index = getElementCount( array, endIndex );
		if ( index > startIndex )
		{
			if ( array instanceof List )
			{
				final List