Inverse function in Scala

Question

Is there a way to express the inverse of any function in Scala?

For example if I have a function f like this:

(x: Int) => x + 1
         


        

Answer 1

From pragmatistic view, unapply method could be used to represent inverse functions:

object f {
  def apply(x: Int) = x + 1
  def unapply(x: Int) = Some(x - 1);
}

val x = 1
val f(y) = f(x)

assert(x == y)