first attempt at using kotlin

something.kt

/**
 * Created by michal on 3/25/2014.
 */
import java.util.ArrayDeque
import java.util.Map;
import java.util.HashMap

trait WjData {
}

private class WjNull : WjData {
    override fun toString() = "null"
}

class WjInt(val value : Int): WjData {
    override fun toString() = value.toString()
}

class WjStr(val value :String) : WjData {
    override fun toString() = '"' + super.toString() + '"'
}

class WjStack : ArrayDeque<WjData>(), WjData {
}

class WjDict : HashMap<WjStr, WjData>(), WjData {
}

public val WJNULL : WjData = WjNull()
fun main(args: Array<String>) {
    val data = WjStack()
    data.push(WJNULL)
    data.push(WjInt(5))
    data.push(WjStack())
    print(data)
}