private - Accessing parameters of the same name of different classes in Scala -

i have specific scenario, in have different abstract classes have child case classes can have different parameters, example:

abstract class ball() {}  case class football(_name: string, _shape: string) extends ball  case class basketball(_name: string, _size: int) extends ball 

and different abstract class:

abstract class food() {}  case class vegetarian(_name: string, calories: int) extends food  case class meat(_name: string, proteincount: int) extends food 

now, problem i'm facing need somehow extract name of of without knowing class is, know always, each class has parameters named _name.

supposing have object of of above classes, i'm trying this:

object.getclass.getdeclaredfield("_name").get(this) 

but i'm getting error:

can not access member of class package.food modifiers "private" 

i tried putting val , var before parameters in class doesnt help. tried doing "setaccessible(true)" in line before get(this), doesn't help.

the obvious clean solution have least common trait these classes:

trait hasname {   def _name: string } 

and can safely obj.asinstanceof[hasname]._name. better yet if manage keep around static information obj hasname, in case obj._name suffices.

if can't of that, reflection way go. can pretty using structural type, in case:

obj.asinstanceof[{ def _name: string }]._name 

note slower above hasname solution, , unchecked @ compile time.