higher_order_patterns.exs

defmodule Pattern do

  @pattern quote do: {:attr, payload}

  defmacro pattern do
    quote do: {:macro, payload}
  end


  def match(unquote(@pattern) = argument) do
    IO.puts "Matched #{inspect argument} with module attr pattern"
  end

  def match(pattern() = argument) do
    IO.puts "Matched #{inspect argument} with macro pattern"
  end

  def match(_) do
    IO.puts "Didn't match anything"
  end
end

Pattern.match 123
# => Didn't match anything

Pattern.match {:macro, 456}
# => Matched {:macro, 456} with macro pattern

Pattern.match {:attr, 789}
# => Matched {:attr, 789} with module attr pattern