Question

I have a scala syntax question – say I have a simple dependency pattern construct like the following

trait Master {
  val foobar

  object SubObject extends SubObject {
      foobar = foobar
  }
}

trait SubObject {
  val foobar
}

Obviously, this will not compile, since the reference
foobar = foobar
is ambiguous.

How do I specify that the RHS of the expression should reference Master’s foobar variable? Is there some sort of special usage of ‘this’ or ‘self’ that I should know about?

Answer 1

I believe the easiest way is to use a self-type definition. In addition to a bunch of cool type-theoretic effects, you can use a self-type to create an alias for “this”. (Haven’t tested this)

trait Master {
  master =>
  val foobar

  object SubObject extends SubObject {
      foobar = master.foobar
  }
}

trait SubObject {
  val foobar
}