test_helper.exs

ExUnit.start

# defprotocol Comparable do
#   @only [BitString]
#   def be(left,right)
#   def le(left,right)
#   def left <= right
# end

# defimpl Comparable, for: BitString do
#   def be(left,right) do
#     binary_to_integer(left) >= binary_to_integer(right)
#   end
#   def le(left,right) do
#     binary_to_integer(left) <= binary_to_integer(right)
#   end
#   def left <= right do
#     Kernel.<= binary_to_integer(left), binary_to_integer(right)
#   end
# end

defmodule Comparable do
  def is_both_integer(left, right) do
    (Regex.match?(%r/[0-9]*/, left) and Regex.match?(%r/^[0-9]*$/, right))
  end

  defmacro left == right do
    quote do
      result = unquote(__MODULE__).is_both_integer unquote(left), unquote(right)
      :io.format "result : ~p~n", [result]
      case result do
        true ->
          unleft  = unquote(left)
          unright = unquote(right)
          # :io.format "unleft  : ~p~n", [unleft]
          # :io.format "unright : ~p~n", [unright]
          unleft = binary_to_integer(unleft)
          unright = binary_to_integer(unright)
          :io.format "unleft  : ~p~n", [unleft]
          :io.format "unright : ~p~n", [unright]

          # result = Kernel.==(binary_to_integer(unquote(left)), binary_to_integer(unquote(right)))
          # :io.format "result : ~p~n", [result]
          # result
          true
        false ->
          # Kernel.==(unquote(left), unquote(right))
          true
      end
    end
  end

  defmacro __using__(_opts) do
    quote do
      import Kernel, except: [==: 2]
      import unquote(__MODULE__), only: [==: 2]
    end
  end
end