Implement a method using a function value in Scala

Question

Is it possible to provide an implementation of a method using a function object/value? I would like to write something in the spirit of:

abstract class A { def f(x:Int) : Int }

class B extends A { f = identity }

Answer 1

You can use a field of type function like this:

abstract class A { val f: (Int) => Int}

val identity = (x: Int) => x*x

class B extends A { override val f = identity }