Visibility rules

There are times when we don't want to let another class or similar construct use a few members. Here, we can use Scala's provided access modifiers. How we achieve control over the accessibility of members of our classes/traits/objects is through private, public, or protected access modifiers. Take a look at the following example:

package restaurant 
 
package privaterestaurant { 
 
  case class Dish(name: String) 
 
  trait Kitchen { 
    self: PrivateRestaurant => 
 
    private val secret = "Secret to tasty dish" //Think of a secret logical evaluation resulting in value, we don't want to expose. 
 
    def cookMyDish: Option[Dish] = Some(Dish(secret)) 
 
  } 
 
  class PrivateRestaurant extends Kitchen { 
 
    def serveDishWithSecret = Dish(secret) // Symbol secret is inaccessible from this place. 
 
    def serveDish = cookMyDish // Works fine 
  } 
 
} 

Here, we have some trait named Kitchen. It has a secret way of cooking a really tasty dish, but only for PrivateRestaurant...