kotlin-examples/Writerside/topics/Enum.md

열거형

enum class Direction {
    NORTH, SOUTH, EAST, WEST
}

enum class Color(val rgb: Int) {
    RED(0xff0000),
    GREEN(0x00ff00),
    BLUE(0x0000ff)
}

val dir = Direction.valueOf("NORTH")
for (item in Direction.values()) {
    // ...
}

익명 클래스

enum class State {
    WAITING {
        override fun signal() = TALKING
    },
    TALKING {
        override fun signal() = WAITING
    }

    abstract fun signal(): State
}

인터페이스

enum class IntArithmetics : BinaryOperator<Int>, IntBinaryOperator {
    PLUS {
        override fun apply(t: Int, u: Int): Int = t + u
    },
    TIMES {
        override fun apply(t: Int, u: Int): Int = t * u
    };

    override fun applyAsInt(t: Int, u: Int) = apply(t, u)
}