src/main/java/org/luaj/vm3/Metatable.java

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 * Copyright (c) 2013 Luaj.org. All rights reserved.
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 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
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 * furnished to do so, subject to the following conditions:
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 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
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 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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package org.luaj.vm3;

import org.luaj.vm3.LuaTable.Slot;

/**
 * Provides operations that depend on the __mode key of the metatable.
 */
interface Metatable {

	/** Return whether or not this table's keys are weak. */
	public boolean useWeakKeys();

	/** Return whether or not this table's values are weak. */
	public boolean useWeakValues();

	/** Return this metatable as a LuaValue. */
	public LuaValue toLuaValue();

	/** Return an instance of Slot appropriate for the given key and value. */
	public Slot entry(LuaValue key, LuaValue value);

	/** Returns the given value wrapped in a weak reference if appropriate. */
	public LuaValue wrap(LuaValue value);

	/**
	 * Returns the value at the given index in the array, or null if it is a weak reference that
	 * has been dropped.
	 */
	public LuaValue arrayget(LuaValue[] array, int index);
}