EitherN.kt

typealias Either7<A, B, C, D, E, F, G> = Either<A, Either<B, Either<C, Either<D, Either<E, Either<F, G>>>>>>
typealias Either6<A, B, C, D, E, F> = Either7<A, B, C, D, E, F, Nothing>
typealias Either5<A, B, C, D, E> = Either7<A, B, C, D, E, Nothing, Nothing>
typealias Either4<A, B, C, D> = Either7<A, B, C, D, Nothing, Nothing, Nothing>
typealias Either3<A, B, C> = Either7<A, B, C, Nothing, Nothing, Nothing, Nothing>

fun <A, B, C, D, E, F, G, R> Either7<A, B, C, D, E, F, G>.fold(
        ifa: (A) -> R,
        ifb: (B) -> R,
        ifc: (C) -> R,
        ifd: (D) -> R,
        ife: (E) -> R,
        iff: (F) -> R,
        ifg: (G) -> R
) =
        fold(ifa, { b ->
            b.fold(ifb, { c ->
                c.fold(ifc, { d ->
                    d.fold(ifd, { e ->
                        e.fold(ife, { f ->
                            f.fold(iff, ifg)
                        })
                    })
                })
            })
        })

fun <A, B, C, D, E, F, R> Either6<A, B, C, D, E, F>.fold(
        ifa: (A) -> R,
        ifb: (B) -> R,
        ifc: (C) -> R,
        ifd: (D) -> R,
        ife: (E) -> R,
        iff: (F) -> R
) = fold(ifa, ifb, ifc, ifd, ife, iff, ::self)


fun <A, B, C, D, E, R> Either5<A, B, C, D, E>.fold(
        ifa: (A) -> R,
        ifb: (B) -> R,
        ifc: (C) -> R,
        ifd: (D) -> R,
        ife: (E) -> R
) = fold(ifa, ifb, ifc, ifd, ife, ::self, ::self)

fun <A, B, C, D, R> Either4<A, B, C, D>.fold(
        ifa: (A) -> R,
        ifb: (B) -> R,
        ifc: (C) -> R,
        ifd: (D) -> R
) = fold(ifa, ifb, ifc, ifd, ::self, ::self, ::self)

fun <A, B, C, R> Either3<A, B, C>.fold(
        ifa: (A) -> R,
        ifb: (B) -> R,
        ifc: (C) -> R
) = fold(ifa, ifb, ifc, ::self, ::self, ::self, ::self)

fun <A, B, C, D, E, F, G> Either7<A, B, C, D, E, F, G>.foldAny(): Any =
        fold({ it as Any },
                { it as Any },
                { it as Any },
                { it as Any },
                { it as Any },
                { it as Any },
                { it as Any })

fun <A, B, C, D, E, F, G> A.variant1(): Either7<A, B, C, D, E, F, G> =
        Either.Left(this)

fun <A, B, C, D, E, F, G> B.variant2(): Either7<A, B, C, D, E, F, G> =
        Either.Right(
                Either.Left(this))

fun <A, B, C, D, E, F, G> C.variant3(): Either7<A, B, C, D, E, F, G> =
        Either.Right(
                Either.Right(
                        Either.Left(this)))

fun <A, B, C, D, E, F, G> D.variant4(): Either7<A, B, C, D, E, F, G> =
        Either.Right(
                Either.Right(
                        Either.Right(
                                Either.Left(this))))

fun <A, B, C, D, E, F, G> E.variant5(): Either7<A, B, C, D, E, F, G> =
        Either.Right(
                Either.Right(
                        Either.Right(
                                Either.Right(
                                        Either.Left(this)))))

fun <A, B, C, D, E, F, G> F.variant6(): Either7<A, B, C, D, E, F, G> =
        Either.Right(
                Either.Right(
                        Either.Right(
                                Either.Right(
                                        Either.Right(
                                                Either.Left(this))))))

fun <A, B, C, D, E, F, G> G.variant7(): Either7<A, B, C, D, E, F, G> =
        Either.Right(
                Either.Right(
                        Either.Right(
                                Either.Right(
                                        Either.Right(
                                                Either.Right(
                                                        this))))))