ToString.scala

package com.simplaex.gist

import java.util.Objects

object ToString {

  trait Formattable {
    override def toString: String = {
      val sb = new StringBuilder
      for (field <- getClass.getDeclaredFields if !field.isSynthetic) {
        val name = field.getName
        field.setAccessible(true)
        val value = field.get(this)
        sb.append(name)
        sb.append(" = ")
        value match {
          case x: Array[_] =>
            sb.append(x.mkString("[", ",", "]"))

          case x =>
            sb.append(Objects.toString(x))
        }
        sb.append("\n")
      }
      sb.toString
    }
  }

  case class X(a: Array[Int], b: String) extends Formattable

  def main(args: Array[String]): Unit = {

    println(X(Array[Int](1, 2, 3), "hello"))

    // prints
    // a = [1,2,3]
    // b = hello
  }

}