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 java.util;

import cc.squirreljme.runtime.cldc.annotation.Api;

/**
 * This is an abstract set which provides only a few more methods than the
 * base collection class.
 *
 * @param <E> The storage type.
 * @since 2018/12/07
 */
@Api
public abstract class AbstractSet<E>
    extends AbstractCollection<E>
    implements Set<E>
{
    /**
     * Requires that the class be extended.
     *
     * @since 2018/10/10
     */
    @Api
    protected AbstractSet()
    {
    }
    
    /**
     * {@inheritDoc}
     * @since 2018/12/07
     */
    @Override
    public boolean equals(Object __o)
    {
        if (__o == this)
            return true;
        
        if (!(__o instanceof Set))
            return false;
        
        // Compare size first
        Set<?> o = (Set<?>)__o;
        if (this.size() != o.size())
            return false;
        
        // Just check if this set contains everything in the other set, note
        // that this only works if the sets are the same size
        return this.containsAll(o);
    }
    
    /**
     * {@inheritDoc}
     * @since 2018/12/07
     */
    @Override
    public int hashCode()
    {
        int rv = 0;
        for (E e : this)
            rv += (e == null ? 0 : e.hashCode());
        return rv;
    }
    
    /**
     * {@inheritDoc}
     * @since 2018/12/07
     */
    @Override
    public boolean removeAll(Collection<?> __c)
        throws NullPointerException
    {
        if (__c == null)
            throw new NullPointerException("NARG");
        
        // Iterate over our set and remove
        boolean did = false;
        if (this.size() <= __c.size())
        {
            for (Iterator<E> it = this.iterator(); it.hasNext();)
            {
                E e = it.next();
                
                if (__c.contains(e))
                {
                    it.remove();
                    did = true;
                }
            }
        }
        
        // Iterate over the other set and remove from ours
        else
        {
            for (Iterator<?> it = __c.iterator(); it.hasNext();)
            {
                Object e = it.next();
                
                if (this.contains(e))
                {
                    this.remove(e);
                    did = true;
                }
            }
        }
        
        return did;
    }
}