Generic unzip Lists[TupleN] with Shapeless

generic-unzip.scala

import shapeless._

object emptyList extends Poly0 {
  implicit def default[T] = at[List[T]](List.empty)
}

object appendList extends Poly2 {
  implicit def default[T] = at[T, List[T]](_ :: _)
}

def unzip[P, L <: HList, LL <: HList, T](list: List[P])(
  implicit
    gen   : Generic.Aux[P, L],
    mapped: ops.hlist.Mapped.Aux[L, List, LL],
    append: ops.hlist.ZipWith.Aux[L, LL, appendList.type, LL],
    empty : ops.hlist.FillWith[emptyList.type, LL],
    tup   : ops.hlist.Tupler.Aux[LL, T]
): T =
  tup(list.foldRight(empty())((v, acc) => append(gen.to(v), acc)))

val input: List[(String, Int, String)] = List(("hello", 1, "world"), ("foo", 2, "bar"))
val (z0, z1, z2) = unzip(input)

println(z0) // List(hello, world)
println(z1) // List(1, 2)
println(z2) // List(world, bar)

That is pretty handy 👍