rustStyleResult.kt

class ResultEliminatorCurrying0<T, R> {
    @Suppress("FunctionName")
    fun OK(ok: (T) -> R): ResultEliminatorCurrying1<T, R> = ResultEliminatorCurrying1(ok)
}

class ResultEliminatorCurrying1<T, R>(internal val ok: (T) -> R)

@Suppress("FunctionName")
infix fun <T, R> ResultEliminatorCurrying1<T, R>.FAIL(fail: (Throwable) -> R): ResultEliminator<T, R> = ResultEliminator(ok, fail)
class ResultEliminator<T, R>(val ok: (T) -> R, val fail: (Throwable) -> R)

fun <T> ofSuccess(data: T): Result<T> = Result(Wrapper(data), null, true)
fun <T> ofFail(throwable: Throwable): Result<T> = Result(null, Wrapper(throwable), false)
class Wrapper<T>(val value: T)
class Result<T> internal constructor(private val data: Wrapper<T>?, private val err: Wrapper<Throwable>?, private val success: Boolean) {
    fun <R> match(eliminatorFactory: ResultEliminatorCurrying0<T, R>.() -> ResultEliminator<T, R>): R {
        val eliminator = eliminatorFactory(ResultEliminatorCurrying0())
        return if (success) {
            eliminator.ok(data!!.value)
        } else {
            eliminator.fail(err!!.value)
        }
    }
}

fun main() {
    val result: Int? = ofSuccess(null).match {
        OK {
            it
        } FAIL {
            throw it
        }
    }
    println(result)
}