Case class morpher in scala

Morph.scala

import shapeless._, syntax.singleton._, record._, ops.hlist._

/**
  * Given an instance A and it's generic representation AR and function f from AR => BR
  * we can covert A to B if we also have the generic representation of BR as B
  * We also handle misalignments using shapeless's align typeclass (https://stackoverflow.com/questions/29242873/shapeless-turn-a-case-class-into-another-with-fields-in-different-order)
  */
case class Morph[A, AR](a: A)(implicit reprA: LabelledGeneric.Aux[A, AR]) {
  // Why this DSL you say? Hack to get around scalac idiocy: https://stackoverflow.com/a/46614684/471136
  def to[B] = new {
    //TODO: Add a better @ImplicitNotFound compile error message when a typo happens here
    def apply[BR <: HList, BR2 <: HList](f: AR => BR2)(implicit reprB: LabelledGeneric.Aux[B, BR], align: Align[BR2, BR]): B =
      reprB.from(align(f(reprA.to(a))))
  }
}

/*
e.g.

Morph(arm).to[CanonicalizedArmTransaction](_
      .:+('card_switch                ->> arm.crd_port.map(_.take(3)))
      .:+('derived_deci_cd            ->> arm.deci_cd.orElse(arm.crd_port.collect{case port if port.startsWith("PAS") => "A"}))
      .:+('canonical_mer_nm           ->> canonical)
      .:+('canonical_mer_nm_clean     ->> cleaned)
      .:+('canonicalized_acquirer_id  ->> arm.acquirer_id.map(_.collapseWhiteSpaces.toUpperCase))
      .:+('canonicalized_crd_port     ->> arm.crd_port.map(_.collapseWhiteSpaces.toUpperCase))
      .:+('canonicalized_sic_cd       ->> arm.sic_cd.map(_.collapseWhiteSpaces.toUpperCase))
      .:+('canonicalized_mer_id       ->> arm.mer_id.map(Canonicalizer.aggressivelySanitize).map(_.toUpperCase))
    )
    */