Does anyone know if there is an idiomatic way to name the inner value of a Scala Value Class? Say I have a value class for a product id, is it better defined as:
case class ProductId(productId:String) extends AnyVal
case class ProductId(underlying:String) extends AnyVal
case class ProductId(value:String) extends AnyVal
?
Is it just a matter of preference or is there an idiomatic guideline?
The idiomatic approach is to make it a private val, now that you can.
The standard library, so far as standards go, prefers self.
implicit final class ArrowAssoc[A](private val self: A) extends AnyVal
There is also repr, recalling both the phrase "underlying runtime representation" from the scaladoc for AnyVal and the repr of collections.
class StringOps(override val repr: String) extends AnyVal with StringLike[String]
There's also a smattering of i and n.
Personally, I use the special identifier, YMMV.