Question

A little time ago I found an interresting blog entry, where someone showed how to ensure an object has a specific behaviour. Now I want to do so, but I can’t find the blog. Can anybody show me the syntax?

Answer 1

Do you mean structural types? Here is an example:

class Duck {
  def quack = "quack"
}

class OtherDuck {
  def quack = "mooh"
}

object Test {
  def testQuack (d: {def quack: String}) = d.quack
}

Then you can do:

Test.testQuack(new Duck)
Test.testQuack(new OtherDuck)