CODEWITHSUNDEEP
scalacompositioncase-class
Metropolis
Metropolis

Reputation: 2128

Referencing values or methods in inner case-class directly

I'd like to make the API of a composed case class a little cleaner. So, consider a modified version of the classic example: 

case class Address(street: String, city: String, zip: String) {
    some large collection of methods
}
case class Person(name: String, address: Address) {
    val street = address.street
    val city = address.city
    val zip = address.zip
}

Now, I like this because you can get the address info directly from the person like person.city instead of requiring person.address.city

However if we imagine that there are a large number of values or methods on the Address case class and it would be tedious to val x = address.x in the Person class. Is there some way to directly access field, values, and methods in address from a person without mapping them all by hand?

Upvotes: 0

Views: 34

Answers (1)

Serhii Shynkarenko
Serhii Shynkarenko

Reputation: 726

one option is to use an implicit conversion. but i would not justify how clean this approach is:

case class Address(street: String)
case class Person(name: String, address: Address) {
  private val s = this.street
}
implicit def person2address(p: Person): Address = p.address

Person("alex", Address("street")).street

also self types could be used:

case class Person(name: String, address: Address) {
  _: Address =>
  private val s = street
}

Upvotes: 2

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