案例类字段的简单迭代 [英] Simple Iteration over case class fields

问题描述

我正在尝试编写一个通用方法来迭代案例类的字段:

I'm trying to write a generic method to iterate over a case class's fields :

case class PriceMove(price: Double, delta: Double)

def log(pm : PriceMove) { info("price -> " + price + " delta -> " + delta)}

我需要让 log 能够处理任何案例类.log 的参数类型需要什么才能只处理案例类和实际的通用字段迭代代码?

I need to make log able to handle any case class. What needs to be the argument type for log to handle case classes only and the actual generic field iteration code?

推荐答案

好的，考虑到我附在问题上的两个问题，我会使用以下方法:

Okay, considering the two questions I attached to the question, here is what I'd use:

object Implicits {
  implicit class CaseClassToString(c: AnyRef) {
    def toStringWithFields: String = {
      val fields = (Map[String, Any]() /: c.getClass.getDeclaredFields) { (a, f) =>
        f.setAccessible(true)
        a + (f.getName -> f.get(c))
      }

      s"${c.getClass.getName}(${fields.mkString(", ")})"
    }
  }
}

case class PriceMove(price: Double, delta: Double)

object Test extends App {
  import Implicits._
  println(PriceMove(1.23, 2.56).toStringWithFields)
}

这会产生:

PriceMove(price -> 1.23, delta -> 2.56)

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