some elixir snippets

snippets.ex

defmodule Snippets do
  @doc """
  ## Example:
    expr |> either [:ok, {:ok, _}]
  """
  defmacro either(match, conds) do
    basecond = quote do res -> res end
    matches = Enum.reduce conds, basecond, fn(c, acc) ->
      [quote do unquote(c) -> :ok end | acc]
    end

    quote do
      case unquote(match) do
        unquote(List.flatten matches)
      end
    end
  end

  def eithertest(x) do
    t |> either [:ok, {:ok, _}]
  end
end

:ok = Snippets.eithertest :ok
:ok = Snippets.eithertest {:ok, 1}
:err = Snippets.eithertest :err