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package org.scijava.util;

import java.util.Objects;

/**
 * Miscellaneous utility methods. Every project needs a class like this, right?
 * 
 * @author Curtis Rueden
 */
public final class MiscUtils {

	private MiscUtils() {
		// prevent instantiation of utility class
	}

	/**
	 * Compares two comparable objects, even if one or both of them are null.
	 * 
	 * By convention, nulls are considered less than non-nulls (and will hence
	 * will appear first on sorted lists).
	 * 
	 * 
	 * @param o1 The first object to compare.
	 * @param o2 The second object to compare.
	 * @return The result of {@code o1.compareTo(o2)} unless one or both of them
	 *         is null, in which case nulls are considered less than non-null
	 *         objects.
	 */
	public static > int compare(final T o1,
		final T o2)
	{
		return compare(o1, o2, false);
	}

	/**
	 * Compares two comparable objects, even if one or both of them are null.
	 * 
	 * @param o1 The first object to compare.
	 * @param o2 The second object to compare.
	 * @param heavyNulls If true, nulls will be treated as greater than non-nulls,
	 *          and hence "sink to the bottom" of e.g. sorted lists.
	 * @return The result of {@code o1.compareTo(o2)} unless one or both of them
	 *         is null, in which case the null strategy defined by the
	 *         {@code heavyNulls} flag is used, to define nulls as either less
	 *         than, or greater than, non-null objects.
	 */
	public static > int compare(final T o1,
		final T o2, final boolean heavyNulls)
	{
		if (o1 == null && o2 == null) return 0;
		if (o1 == null) return heavyNulls ? 1 : -1;
		if (o2 == null) return heavyNulls ? -1 : 1;
		return o1.compareTo(o2);
	}

	/**
	 * @deprecated Use {@link Objects#equals(Object, Object)} instead.
	 */
	@Deprecated
	public static boolean equal(final Object o1, final Object o2) {
		return o1 == null ? o2 == null : o1.equals(o2);
	}

}