如何在 Scala 运行时获取类型别名的别名类型？

Question

import scala.reflect.runtime.universe._

object Main {

  final type INeedDetails = (Int, String, Unit, Nothing, Float)

  def main(args: Array[String]): Unit = println {
    typeTag[INeedDetails]
  }

}

上面的代码片段将打印 TypeTag[Main.INeedDetails]。有没有办法从这个TypeTag中提取完整的(Int, String, Unit, Nothing, Float)元组信息？

Answer 1

您可以dealias标签中的类型：

scala> type INeedDetails = (Int, String, Unit, Nothing, Float)
defined type alias INeedDetails

scala> typeTag[INeedDetails].tpe
res1: reflect.runtime.universe.Type = INeedDetails

scala> typeTag[INeedDetails].tpe.dealias
res2: reflect.runtime.universe.Type = (scala.Int, String, scala.Unit, scala.Nothing, scala.Float)