ApplyExample.scala

trait Example {
    import cats.implicits._
  import cats.~>

  type VdomNode
  type StateSnapshot[A]
  type Lens[S, A]

  type Layout1 = VdomNode => VdomNode
  type Layout2 = (VdomNode, VdomNode) => VdomNode

  def render1[A, Z](layout: Layout1)(
    snapshotZ: StateSnapshot[Z]
  )(f: StateSnapshot[Z] => StateSnapshot[A])(renderA: StateSnapshot[A] => VdomNode): VdomNode =
    layout(renderA(f(snapshotZ)))

  def render2[A, B, Z](layout: Layout2)(snapshotZ: StateSnapshot[Z])(
    f1: StateSnapshot[Z] => StateSnapshot[A],
    f2: StateSnapshot[Z] => StateSnapshot[B]
  )(renderA: StateSnapshot[A] => VdomNode, renderB: StateSnapshot[B] => VdomNode): VdomNode =
    layout(renderA(f1(snapshotZ)), renderB(f2(snapshotZ)))

  case class Foo[Z, A](f: StateSnapshot[Z] => StateSnapshot[A], render: StateSnapshot[A] => VdomNode) {
    val func: StateSnapshot[Z] => VdomNode = render compose f
  }
  

  def _render2[A, B, Z](fooA: Foo[Z, A], fooB: Foo[Z, B])(layout2: Layout2): StateSnapshot[Z] => VdomNode =
    (fooA.func, fooB.func).mapN(layout2)

}