Simple Iteration over case class fields

Question

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)}

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?

Answer 1

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)
}

This produces:

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