Small script to understand usage of __using__ / $ elixirc hello_using.exs

hello_using.exs

defmodule MyModule do
  defmacro __using__(_) do
  ┆ quote do
  ┆ ┆ import MyModule

  ┆ ┆ def hi(s) do
  ┆ ┆ ┆ IO.puts "Hi #{s} from #{__MODULE__}"
  ┆ ┆ end
  ┆ end
  end 

  def hello(s) do
  ┆ IO.puts "Hello #{s} from #{__MODULE__}"
  end 
end

defmodule ModA do
  use MyModule
  def my_hello(s), do: 
  ┆ hello(s)
end

ModA.hi("there")
ModA.my_hello("world")

ModA.hello("world") # fail!