Can I override the toString method of an anonymous function in Scala?

Question

I tried to override the toString of an anonymous function in Scala like this:

scala> ()=>{def toString="yes"; 1}
res1: () => Int = <function0>

Which does not work - I want res1 to be "yes" somehow.

Is this possible?

Answer 1

You can't do that with anonymous function literals, you will need to extend the Function trait. E.g.

val f = new (() => Int) {
  override def toString = "yes"
  def apply() = 1
}

or

val f = new Function0[Int] {
  override def toString = "yes"
  def apply() = 1
}