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codeaperature's questions

Martin Hope
codeaperature
Asked: 2025-04-30 01:33:49 +0800 CST
  • 6

一个模式如何匹配此方法的成功或失败：

trait FunctionApi:
     def computeTry(funct: Try[String] => Unit): Unit = ??? // some ops

def actUponTry(functionApi: FunctionApi): String = {

     // This below could be something other than match as 
     // long as `Success` or `Failure` is apparent)

     functionApi.computeTry(...) match
     // When Try is ... (get Try + exception or value)
     // Success(value) => // Act on Success & value
                  s"Success with $value" 
     // Failure(ex) =>    // Act on Failure & ex 
                  s"Failure with exception ${ex.getString}"

}

如果有另一种名为isFunctionApi的方法，那么这个“匹配测试”是否可以更通用？computeTry2computeTry2(funct: Try[Long] => Unit): Unit

不要使用外部库。

也许如何在 Scala 中模式匹配函数？有帮助吗？

也许有办法使用另一个包装特征或方法来提取成功/失败参数？

附加编辑：

最终目标是赋值一个 Promise 来执行 Future。（我想自己做这部分。）调用代码可能如下所示：

val success = Success("Some String")
val succeeding = new FunctionApi:
    def computeTry(continuation: Try[String] => Unit): Unit =
        continuation(success)
val wasSuccess = actUponTry(succeeding).computeTry()

编辑#2：我设法让它工作 - 随着问题的发展，我将关闭这个问题。

  def actUponTry(functionApi: FunctionBasedApi): StringBasedApi = {
    class StringBasedApiX extends StringBasedApi {
      def computeTry(): String = {
        functionApi.computeTry {
          case Success(value) => s"Success with $value"
          case Failure(ex) => s"Failure with exception ${ex.getMessage}"
        }
      }
    }
    new StringBasedApiX
  }

/**
  * Dummy example of a callback-based API
  */

trait FunctionBasedApi:
  def computeTry(funct: Try[String] => String): String

  /**
   * API similar to [[CallbackBasedApi]], but based on `String` instead
   */
trait StringBasedApi:
  def computeTry(): String

附测试代码：

  test("test matching") {
    val success = Success("Some String")
    val stringBasedApi = new FunctionBasedApi:
      def computeTry(funct: Try[String] => String): String = funct(success)
    val wasSuccess = actUponTry(stringBasedApi).computeTry()
    assertEquals(wasSuccess,  s"Success with ${success.get}")
  }

但我发现我尝试使用期货来做到这一点的方式与上面的代码不同（上面的...我无法进行模式匹配）。

scala