Nested entity mapping with Slick 1.x

gistfile1.scala

case class Part1(i1: Int, i2: String)
case class Part2(i1: String, i2: Int)
case class Whole(p1: Part1, p2: Part2)
class Tuple2Mapper[Entity,Component1,Tuple1,Component2,Tuple2](
  entityFactory: (Component1,Component2) => Entity,
  entityExtractor: Entity => Option[(Component1,Component2)],
  component1factory: Tuple1 => Component1,
  component1extractor: Component1 => Option[Tuple1],
  component2factory: Tuple2 => Component2,
  component2extractor: Component2 => Option[Tuple2]
){
  def apply( tuple1: Tuple1, tuple2: Tuple2 ) =
    entityFactory(component1factory(tuple1), component2factory(tuple2))
  def unapply(entity: Entity) = entityExtractor(entity).map(tuple => (
    component1extractor(tuple._1).get,
    component2extractor(tuple._2).get
  ))
}

object WholeMapper extends Tuple2Mapper(
  Whole,
  Whole.unapply,
  Part1.tupled,
  Part1.unapply,
  Part2.tupled,
  Part2.unapply
)

object T extends Table[(Int,String,String,Int)]("t_nested") {
  def p1 = column[Int]("p1")
  def p2 = column[String]("p2")
  def p3 = column[String]("p3")
  def p4 = column[Int]("p4")
  def * = p1 ~ p2 ~ p3 ~ p4
  def nested = ((p1,p2), (p3,p4))
}

val data = Seq(
  Whole(
    Part1(1, "2"),
    Part2("3", 4)
  )
)

T.ddl.create
T.nested.shaped.insertAll(data.map(WholeMapper.unapply(_).get):_*)

assertEquals(data, Query(T).map(_.nested).run.map((WholeMapper.apply _).tupled))