How do I extend or specialize a generic type in EK9?

  BaseList of type T as open
    items as List of T?

  NameList is BaseList of String

  NameList is BaseList of String
    findByPrefix()
      -> prefix as String
      <- rtn as String?

  intCompare <- () is compareFunc of Integer as function

#!ek9
defines module qa.generics.extending

  defines function

    compareFunc() of type T as open
      ->
        item1 as T
        item2 as T
      <-
        rtn as Integer := item1 <=> item2

  defines class

    BaseList of type T as open
      items as List of T?

      BaseList()
        items :=? List() of T

      BaseList()
        -> item as T
        items: List() of T
        items += item

      addItem()
        -> item as T
        if not items?
          items: List() of T
        items += item

      count() as pure
        <- rtn as Integer: 0
        if items?
          rtn: length items

      default operator ?

    // Specialization: concrete type from generic
    NameList is BaseList of String

      default operator ?

  defines program

    ExtendingGenericsDemo()
      stdout <- Stdout()

      // === GENERIC FUNCTION INSTANTIATION ===

      intCompare <- () is compareFunc of Integer as function
      result <- intCompare(10, 20)
      stdout.println(`Compare 10 vs 20: ${result}`)

      strCompare <- () extends compareFunc of String as function
      strResult <- strCompare("apple", "banana")
      stdout.println(`Compare apple vs banana: ${strResult}`)

      // === SPECIALIZED CLASS ===

      names <- NameList()
      names.addItem("Alice")
      names.addItem("Bob")
      stdout.println(`Name count: ${names.count()}`)

intCompare <- () is compareFunc of Integer as class

intCompare <- () is compareFunc of Integer as function