Diamond.scala

trait A {
  def foo(text: String) = printf("a says:" + text)
}
 
trait B extends A {
  override def foo(text: String) = printf("b says:" + text)
}
 
trait C extends A {
  override def foo(text: String) = printf("c says:" + text)
}
 
class D extends B with C
 
object main {
 
  def main(args: Array[String]) {
    val test = new D
    test.foo("hi")
  }
}

Scala allows multiple instantiation of traits, which allows for multiple inheritance by adding a distinction between the class hierarchy and the trait hierarchy. A class can only inherit from a single class, but can mix-in as many traits as desired. Scala resolves method names using a right-first depth-first search of extended 'traits', before eliminating all but the last occurrence of each module in the resulting list. So, the resolution order is: [D, C, A, B, A], which reduces down to [D, C, B, A].
Tcl allows multiple parent classes; the order of specification in the class declaration affects the name resolution for members using the C3 linearization algorithm.[10]