很难猜出你将如何使用这个函数。
根据您的使用情形，您可以尝试Type

def typeGetter(`type`: DataType): universe.Type = `type` match {
  case StringType => universe.typeOf[String]
  case x: DecimalType => universe.typeOf[java.math.BigDecimal]
  case LongType => universe.typeOf[Long]
  case IntegerType => universe.typeOf[Int]
}

或TypeTag

def typeGetter(`type`: DataType): universe.TypeTag[_] = `type` match {
  case StringType => universe.typeTag[String]
  case x: DecimalType => universe.typeTag[java.math.BigDecimal]
  case LongType => universe.typeTag[Long]
  case IntegerType => universe.typeTag[Int]
}

或Class

def typeGetter(`type`: DataType): Class[_] = `type` match {
  case StringType => classOf[String]
  case x: DecimalType => classOf[java.math.BigDecimal]
  case LongType => classOf[Long]
  case IntegerType => classOf[Int]
}

或ClassTag

def typeGetter(`type`: DataType): scala.reflect.ClassTag[_] = `type` match {
  case StringType => scala.reflect.classTag[String]
  case x: DecimalType => scala.reflect.classTag[java.math.BigDecimal]
  case LongType => scala.reflect.classTag[Long]
  case IntegerType => scala.reflect.classTag[Int]
}

或类型类

trait TypeGetter[T] {
  type Out
}
object TypeGetter {
  type Aux[T, Out0] = TypeGetter[T] { type Out = Out0 }
    
  implicit val string: Aux[StringType, String] = null
  implicit val decimal: Aux[DecimalType, BigDecimal] = null
  implicit val long: Aux[LongType, Long] = null
  implicit val integer: Aux[IntegerType, Int] = null
}
  
def foo[T](implicit typeGetter: TypeGetter[T]): typeGetter.Out = ???