FlattenTupleExample

FlattenTupleExample.scala

object FlattenTuple {

  import shapeless._
  import ops.tuple.FlatMapper
  import syntax.std.tuple._

  trait LowPriorityFlattenTuple extends Poly1 {
    implicit def default[T] = at[T](Tuple1(_))
  }

  object flattenTuple extends LowPriorityFlattenTuple {
    implicit def caseTuple[P <: Product](implicit fm: FlatMapper[P, flattenTuple.type]) =
      at[P](_ flatMap flattenTuple)
  }

  implicit class TupleFlattenOps[P <: Product](p: P) {
    def flatten(implicit fm: FlatMapper[P, flattenTuple.type]) = flattenTuple(p)
  }
}

object FlattenTupleExample extends App {
  import FlattenTuple._
  
  println((Tuple1(Some(1)), 11).flatten)
  println(((Some(1), Some(2)), 11).flatten)
  println(((Some(1), Some(2), Some(3)), 11).flatten)
  println(((Some(1), Some(2), Some(3), Some(4)), 11).flatten)
  println(((Some(1), Some(2), Some(3), Some(4), Some(5)), 11).flatten)
  println(((Some(1), Some(2), Some(3), Some(4), Some(5), Some(6)), 11).flatten)
  println(((Some(1), Some(2), Some(3), Some(4), Some(5), Some(6), Some(7)), 11).flatten)
  println(((Some(1), Some(2), Some(3), Some(4), Some(5), Some(6), Some(7), Some(8)), 11).flatten)
  println(((Some(1), Some(2), Some(3), Some(4), Some(5), Some(6), Some(7), Some(8), Some(9)), 11).flatten)
  println(((Some(1), Some(2), Some(3), Some(4), Some(5), Some(6), Some(7), Some(8), Some(9), Some(10)), 11).flatten)

  /*
  prints:

  (1,11)
  (1,2,11)
  (1,2,3,11)
  (1,2,3,4,11)
  ((Some(1),Some(2),Some(3),Some(4),Some(5)),11)
  ((Some(1),Some(2),Some(3),Some(4),Some(5),Some(6)),11)
  ((Some(1),Some(2),Some(3),Some(4),Some(5),Some(6),Some(7)),11)
  ((Some(1),Some(2),Some(3),Some(4),Some(5),Some(6),Some(7),Some(8)),11)
  ((Some(1),Some(2),Some(3),Some(4),Some(5),Some(6),Some(7),Some(8),Some(9)),11)
  ((Some(1),Some(2),Some(3),Some(4),Some(5),Some(6),Some(7),Some(8),Some(9),Some(10)),11)
   */
}