Expected start of definition error in Scala

Question

I'm trying to run the Scala code presented in this math.stackexchange post (please see the second answer), but seem to be running into issues in the line starting with implicit def.... The compiler is telling me error: expected start of definition.

Any thoughts? Thanks!

I should add that I'm using http://www.tutorialspoint.com/compile_scala_online.php to run my code.

Answer 1

Just tried your example on Scala REPL and it works for me as expected.

Move the implicit def to an object:

object MyImplicits {
  /** Pimp `Set[X]` with a few convenient operators */
  implicit def logicalSetOps[X](set: Set[X]) = new {
    def and(other: Set[X]) = set.intersect(other)
    def or(other: Set[X]) = set.union(other)
    def minus(other: Set[X]) = set.filterNot(other.contains)
  }
}

and then do:

import MyImplicits._

That should work for you.

Answer 2

The code in that example is meant to be pasted either into a worksheet or into the REPL.

It should also work to paste it inside an

object MathApp extends App {
  // paste here
}

Then you can run MathApp as scala or java application.