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LUAK - Kotlin port of LuaJ (fork of https://github.com/korlibs/korge-luak)
/*******************************************************************************
* Copyright (c) 2009-2011 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 kotlin.native.concurrent.*
import kotlin.reflect.*
/**
* Class to encapsulate behavior of the singleton instance `nil`
*
*
* There will be one instance of this class, [LuaValue.NIL],
* per Java virtual machine.
* However, the [Varargs] instance [LuaValue.NONE]
* which is the empty list,
* is also considered treated as a nil value by default.
*
*
* Although it is possible to test for nil using Java == operator,
* the recommended approach is to use the method [LuaValue.isnil]
* instead. By using that any ambiguities between
* [LuaValue.NIL] and [LuaValue.NONE] are avoided.
* @see LuaValue
*
* @see LuaValue.NIL
*/
open class LuaNil internal constructor() : LuaValue() {
override fun type(): Int = LuaValue.TNIL
override fun toString(): String = "nil"
override fun typename(): String = "nil"
override fun tojstring(): String = "nil"
override fun not(): LuaValue = LuaValue.BTRUE
override fun toboolean(): Boolean = false
override fun isnil(): Boolean = true
override fun getmetatable(): LuaValue? = s_metatable
override fun equals(o: Any?): Boolean = o is LuaNil
override fun checknotnil(): LuaValue = argerror("value")
override fun isvalidkey(): Boolean = false
// optional argument conversions - nil alwas falls badk to default value
override fun optboolean(defval: Boolean): Boolean = defval
override fun optclosure(defval: LuaClosure?): LuaClosure? = defval
override fun optdouble(defval: Double): Double = defval
override fun optfunction(defval: LuaFunction?): LuaFunction? = defval
override fun optint(defval: Int): Int = defval
override fun optinteger(defval: LuaInteger?): LuaInteger? = defval
override fun optlong(defval: Long): Long = defval
override fun optnumber(defval: LuaNumber?): LuaNumber? = defval
override fun opttable(defval: LuaTable?): LuaTable? = defval
override fun optthread(defval: LuaThread?): LuaThread? = defval
override fun optjstring(defval: String?): String? = defval
override fun optstring(defval: LuaString?): LuaString? = defval
override fun optuserdata(defval: Any?): Any? = defval
override fun optuserdata(c: KClass<*>, defval: Any?): Any? = defval
override fun optvalue(defval: LuaValue): LuaValue = defval
companion object {
@kotlin.jvm.JvmField internal val _NIL = LuaNil()
var s_metatable: LuaValue?
get() = LuaNil_metatable
set(value) {
LuaNil_metatable = value
}
}
}
@ThreadLocal
private var LuaNil_metatable: LuaValue? = null