gistfile1.ex

defmodule PersonPrinter do
  def say_hello(Person[first_name: first, last_name: "Dudington"]) do
    "hey it's my brother, #{first}!"
  end

  def say_hello(Person[first_name: first]) do
    "hello, #{first}"
  end

  def say_hello(person=Person[last_name: "Dudington"]) do
    "hey #{person.first_name}"
  end
end

bro = Person.new first_name: "Bro", last_name: "Dudington"
stranger = Person.new first_name: "Stranger", last_name: "von Strangehands"
PersonPrinter.say_hello(bro)
PersonPrinter.say_hello(stranger)