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 net.multiphasicapps.collections;

import java.util.AbstractMap;
import java.util.Map;
import java.util.Set;

/**
 * This represents an identity map.
 *
 * @param <K> The key type.
 * @param <V> The value type.
 * @since 2021/11/28
 */
public final class IdentityMap<K, V>
    extends AbstractMap<K, V>
{
    /** The backing map. */
    private final Map<Identity<K>, V> _map;
    
    /**
     * Initializes the base map.
     * 
     * @param __backing The backing map.
     * @throws NullPointerException On null arguments.
     * @since 2021/11/28
     */
    public IdentityMap(Map<Identity<K>, V> __backing)
        throws NullPointerException
    {
        if (__backing == null)
            throw new NullPointerException("NARG");
        
        this._map = __backing;
    }
    
    /**
     * {@inheritDoc}
     * @since 2021/11/28
     */
    @Override
    public void clear()
    {
        this._map.clear();
    }
    
    /**
     * {@inheritDoc}
     * @since 2021/11/28
     */
    @SuppressWarnings("unchecked")
    @Override
    public boolean containsKey(Object __k)
    {
        return this._map.containsKey(new Identity<K>((K)__k));
    }
    
    /**
     * {@inheritDoc}
     * @since 2021/11/28
     */
    @Override
    public Set<Entry<K, V>> entrySet()
    {
        return new __IdentityKeySetView__<K, V>(this._map.entrySet());
    }
    
    /**
     * {@inheritDoc}
     * @since 2021/11/28
     * @param __k
     */
    @SuppressWarnings("unchecked")
    @Override
    public V get(Object __k)
    {
        return this._map.get(new Identity<K>((K)__k));
    }
    
    /**
     * {@inheritDoc}
     * @since 2021/11/28
     */
    @Override
    public V put(K __k, V __v)
    {
        return this._map.put(new Identity<K>(__k), __v);
    }
    
    /**
     * {@inheritDoc}
     * @since 2021/11/28
     */
    @Override
    public int size()
    {
        return this._map.size();
    }
}