How to avoid dependency injection in Scala?

Question

I read Dependency Injection Without the Gymnastics PDF which indicates there\'s no need for any fancy DI framework, but it\'s beyond my grasp (at least without concrete examples

Answer 1

I think @om-nom-nom's answer is quite close to what you want. Here is what I've got:

class A {
  self: B with C => 

  def sum = tripleD + doubleD
}

trait B { 
  self: D => 

  def tripleD = x * 3
}

trait C {
  self: D => 

  def doubleD = x * 2
}

trait D extends B with C {
  val x: Int
}

trait E extends D {
  val x = 3
}

trait F extends D {
  val x = 4
}

val a = new A with E
val b = new A with F

println("a.sum = " + a.sum)
println("b.sum = " + b.sum)