A simple example of using our listFunctor that we defined in the preceding section can be seen as follows:
object FunctorsExample { def main(args: Array[String]): Unit = { val numbers = List(1, 2, 3, 4, 5, 6) val mapping = Map( 1 -> "one", 2 -> "two", 3 -> "three", 4 -> "four", 5 -> "five", 6 -> "six" ) System.out.println(s"The numbers doubled are: ${listFunctor.map(numbers)(_ * 2)}") System.out.println(s"The numbers with strings are: ${listFunctor.map(numbers)(i => (i, mapping(i)))}") }}
The output of the preceding example is shown in the following screenshot:
As you can see, functors don't really do much by themselves. ...
