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Multiplatform Kotlin LuaJ port (LUA interpreter)

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/*******************************************************************************
 * Copyright (c) 2013 Luaj.org. All rights reserved.
 *
 * 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
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */
package org.luaj.vm2

import org.luaj.vm2.LuaTable.Slot

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

    /** Return whether or not this table's keys are weak.  */
    fun useWeakKeys(): Boolean

    /** Return whether or not this table's values are weak.  */
    fun useWeakValues(): Boolean

    /** Return this metatable as a LuaValue.  */
    fun toLuaValue(): LuaValue

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

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

    /**
     * Returns the value at the given index in the array, or null if it is a weak reference that
     * has been dropped.
     */
    fun arrayget(array: Array, index: Int): LuaValue?
}