macros.ex

defmodule Ddd.Macros  do
  defmacro __using__ do
    @rules []
  end
  
  defmacro defrule(signature, body) do
    quote do
      # Prepend the signature to the list of rules....
      @rules [ signature | @rules]
      
      def unquote(signature) do
        unquote(body[:do])
      end
    end
  end
  
end



defmodule Ddd.Actions do 
  use Ddd.Macros 
  
  defrule something(items) do
      ....
  end 
  
end

defmodule Ddd.Macros  do
  defmacro __using__(_opts) do
    quote do
      import unquote(__MODULE__)
      Module.register_attribute __MODULE__, :rules, accumulate: true
    end
  end

  defmacro defrule(signature, body) do
    quote do
      # append the signature to the list of rules....
      @rules signature

      def unquote(signature) do
        unquote(body[:do])
      end
    end
  end

end



defmodule Ddd.Actions do 
  use Ddd.Macros 

  defrule something(items) do
      ....
  end 

end