def toSpec[T <: Product]()

in core/src/main/scala-2.13/com/spotify/featran/converters/CaseClassConverter.scala [43:120]
74 lines of code
43 McCabe index (conditional complexity)

  def toSpec[T <: Product](implicit
    tt: TypeTag[T],
    ct: ClassTag[T],
    d: DefaultTransform[Double]
  ): FeatureSpec[T] =
    properties[T].zipWithIndex
      .foldLeft(FeatureSpec.of[T]) { case (s, (m, idx)) =>
        @transient val method = m
        val name = method.name.toString
        method.info.resultType match {
          // Native Types
          case c if c =:= typeOf[Int] =>
            s.required[Double](v => get(v, idx).asInstanceOf[Int].toDouble)(d(name))
          case c if c =:= typeOf[Long] =>
            s.required[Double](v => get(v, idx).asInstanceOf[Long].toDouble)(d(name))
          case c if c =:= typeOf[Short] =>
            s.required[Double](v => get(v, idx).asInstanceOf[Short].toDouble)(d(name))
          case c if c =:= typeOf[Boolean] =>
            s.required[Double](v => get(v, idx).asInstanceOf[Boolean].asDouble)(d(name))
          case c if c =:= typeOf[Double] =>
            s.required[Double](v => get(v, idx).asInstanceOf[Double])(d(name))
          // Optional Native Types
          case c if c =:= typeOf[Option[Int]] =>
            s.optional[Double](v => get(v, idx).asInstanceOf[Option[Int]].map(_.toDouble))(
              d(name)
            )
          case c if c =:= typeOf[Option[Long]] =>
            s.optional[Double](v => get(v, idx).asInstanceOf[Option[Long]].map(_.toDouble))(
              d(name)
            )
          case c if c =:= typeOf[Option[Short]] =>
            s.optional[Double](v => get(v, idx).asInstanceOf[Option[Short]].map(_.toDouble))(
              d(name)
            )
          case c if c =:= typeOf[Option[Boolean]] =>
            s.optional[Double](v => get(v, idx).asInstanceOf[Option[Boolean]].map(_.asDouble))(
              d(name)
            )
          case c if c =:= typeOf[Option[Double]] =>
            s.optional[Double](v => get(v, idx).asInstanceOf[Option[Double]])(d(name))
          // Seq Native Types
          case c if c <:< typeOf[Seq[Int]] =>
            s.required(v => get(v, idx).asInstanceOf[Seq[Int]].map(_.toDouble))(
              VectorIdentity(name)
            )
          case c if c <:< typeOf[Seq[Long]] =>
            s.required(v => get(v, idx).asInstanceOf[Seq[Long]].map(_.toDouble))(
              VectorIdentity(name)
            )
          case c if c <:< typeOf[Seq[Short]] =>
            s.required(v => get(v, idx).asInstanceOf[Seq[Short]].map(_.toDouble))(
              VectorIdentity(name)
            )
          case c if c <:< typeOf[Seq[Boolean]] =>
            s.required(v => get(v, idx).asInstanceOf[Seq[Boolean]].map(_.asDouble))(
              VectorIdentity(name)
            )
          case c if c <:< typeOf[Seq[Double]] =>
            s.required(v => get(v, idx).asInstanceOf[Seq[Double]])(VectorIdentity(name))
          // Strings
          case c if c =:= typeOf[String] =>
            s.required[String](v => get(v, idx).asInstanceOf[String])(OneHotEncoder(name))
          case c if c =:= typeOf[Option[String]] =>
            s.optional[String](v => get(v, idx).asInstanceOf[Option[String]])(OneHotEncoder(name))
          case c if c <:< typeOf[Seq[String]] =>
            s.required[Seq[String]](v => get(v, idx).asInstanceOf[Seq[String]])(NHotEncoder(name))
          case c if c <:< typeOf[MDLRecord[String]] =>
            s.required[MDLRecord[String]](v => get(v, idx).asInstanceOf[MDLRecord[String]])(
              MDL(name)
            )
          case c if c <:< typeOf[Seq[WeightedLabel]] =>
            s.required[Seq[WeightedLabel]](v => get(v, idx).asInstanceOf[Seq[WeightedLabel]])(
              NHotWeightedEncoder(name)
            )
          case _ =>
            sys.error("Not matching Conversions for " + m.toString)
        }
      }