Get keys and field types of a case class with Shapeless

ShapelessKeysAndTypeNames.scala

load.ivy("com.chuusai" %% "shapeless" % "2.3.0")

@

import scala.reflect._
import shapeless._
import shapeless.record._
import shapeless.labelled._
import shapeless.ops.record._

case class Foo(x: String, y: Int)

val generic = LabelledGeneric[Foo]

// Get the field names of a case class with Shapeless
val keys = implicitly[Keys[generic.Repr]].apply

// Now get the class objects as well
trait FieldTypes[L <: HList] extends DepFn0 { type Out <: HList }

object FieldTypes {
  type Aux[L <: HList, Out0 <: HList] = FieldTypes[L] { type Out = Out0 }

  def apply[L <: HList](implicit fieldTypes: FieldTypes[L]): Aux[L, fieldTypes.Out] = fieldTypes

  implicit def hnilFieldTypes[L <: HNil]: Aux[L, HNil] = new FieldTypes[L] {
    type Out = HNil

    def apply(): Out = HNil
  }

  implicit def hlistFieldTypes[K, V, Rest <: HList](
    implicit fieldTypesRest: FieldTypes[Rest],
    clazz: ClassTag[V]
  ): Aux[FieldType[K, V] :: Rest, String :: fieldTypesRest.Out] = new FieldTypes[FieldType[K, V] :: Rest] {
    type Out = String :: fieldTypesRest.Out

    def apply(): Out = clazz.runtimeClass.getName :: fieldTypesRest()
  }
}

val fieldTypes = implicitly[FieldTypes[generic.Repr]].apply