SquirrelJME/SquirrelJME

// -*- Mode: Java; indent-tabs-mode: t; tab-width: 4 -*-
// ---------------------------------------------------------------------------
// SquirrelJME
//     Copyright (C) Stephanie Gawroriski <xer@multiphasicapps.net>
// ---------------------------------------------------------------------------
// SquirrelJME is under the Mozilla Public License Version 2.0.
// See license.mkd for licensing and copyright information.
// ---------------------------------------------------------------------------

package cc.squirreljme.runtime.cldc.util;

import cc.squirreljme.runtime.cldc.debug.Debugging;

/**
 * This class manages a boxed like representation of unsigned integers.
 *
 * @since 2018/11/03
 */
public final class UnsignedInteger
    extends Number
    implements Comparable<UnsignedInteger>
{
    /** The stored value. */
    protected final int value;
    
    /**
     * Initializes the unsigned integer.
     *
     * @param __v The value to use.
     * @since 2018/11/03
     */
    public UnsignedInteger(int __v)
    {
        throw Debugging.todo();
    }
    
    /**
     * {@inheritDoc}
     * @since 2018/11/03
     */
    @Override
    public final int compareTo(UnsignedInteger __i)
    {
        return UnsignedInteger.compareUnsigned(this.value, __i.value);
    }
    
    /**
     * {@inheritDoc}
     * @since 2018/11/03
     */
    @Override
    public final double doubleValue()
    {
        throw Debugging.todo();
    }
    
    /**
     * {@inheritDoc}
     * @since 2018/11/03
     */
    @Override
    public final float floatValue()
    {
        throw Debugging.todo();
    }
    
    /**
     * {@inheritDoc}
     * @since 2018/11/03
     */
    @Override
    public final boolean equals(Object __o)
    {
        throw Debugging.todo();
    }
    
    /**
     * {@inheritDoc}
     * @since 2018/11/03
     */
    @Override
    public final int hashCode()
    {
        throw Debugging.todo();
    }
    
    /**
     * {@inheritDoc}
     * @since 2018/11/03
     */
    @Override
    public final int intValue()
    {
        throw Debugging.todo();
    }
    
    /**
     * {@inheritDoc}
     * @since 2018/11/03
     */
    @Override
    public final long longValue()
    {
        throw Debugging.todo();
    }
    
    /**
     * Compares two signed values.
     *
     * @param __a The first value.
     * @param __b The second value.
     * @return The resulting comparison.
     * @since 2018/11/03
     */
    public static final int compareSigned(int __a, int __b)
    {
        if (__a == __b)
            return 0;
        else if (__a < __b)
            return -1;
        else
            return 1;
    }
    
    /**
     * Compares a signed and unsigned value.
     *
     * @param __a The first value.
     * @param __ub The second value.
     * @return The resulting comparison.
     * @since 2018/11/03
     */
    public static final int compareSignedUnsigned(int __a, int __ub)
    {
        throw Debugging.todo();
    }
    
    /**
     * Compares two unsigned values.
     *
     * @param __a The first value.
     * @param __b The second value.
     * @return The resulting comparison, {@code 0} if equal or a
     * positive/negative value.
     * @since 2018/11/03
     */
    @SuppressWarnings("MagicNumber")
    public static int compareUnsigned(int __a, int __b)
    {
        // Quick shortcut if they are the same number
        if (__a == __b)
            return 0;
        
        // Check if there is a sign bit
        boolean na = ((__a & 0x8000_0000) != 0),
            nb = ((__b & 0x8000_0000) != 0);
        
        // Comparison is the same as signed integers if the sign is the same
        // 0x80000000 == -2147483648
        // 0xFFFFFFFF == -1
        if (na == nb)
            return UnsignedInteger.compareSigned(__a, __b);
        
        // Only A has sign bit, it is always greater
        else if (na && !nb)
            return 1;
        
        // Only B has sign bit, it is always lesser
        else
            return -1;
    }
}