validateanyProduct.scala

validateanyProduct.scala

def validateProduct[T <: Product](product: T): Seq[String] = product.productIterator.flatMap{value => value match {
  case null => Seq("null attributes are not allowed for " + product)
  case string: String if (string.isEmpty) => Seq("Empty strings are not allowed for " + product)
  case innerProduct: Product => validateProduct(innerProduct)
  case _ => Seq()
}}.toSeq

Yup, like it! Had something like this in mind for cases where you'd want to collect all errors.

I've got something related in mind for Scala 2.10 using macros that does arbitrarily nested detailed comparisons, so that for:

case class Test(first: String, second: String, third: Int)
val test1 = Test("cake", "elephant", 900)
val test2 = Test("moon", "elephant", 1000)
// This method would return Seq("left.first is different to right.first.", "left.third is different to right.third.")
specialComparison(test1, test2)

With all the comparison code created and the types validated as comparable by this mechanism at compile time.

Slightly cleaner, perhaps.

def validateProduct[T <: Product](product: T): Seq[String] = product.productIterator.toSeq collect {
  case null => "null attributes are not allowed for " + product
  case string: String if (string.isEmpty) => "Empty strings are not allowed for " + product
  case innerProduct: Product => validateProduct(innerProduct)
}

Yeah, that's much nicer.