Introduce global state for options so we don't have to pass it around

lib/options.ex

@@ -1,16 +1,22 @@
 defmodule Options do
+  @defaults %{
+    clear_screen: false
+  }
 
-  def parse([]), do: defaults
   def parse(args) do
-    Enum.reduce(args, defaults, fn(arg, acc) ->
+    options = Enum.reduce(args, @defaults, fn(arg, acc) ->
       Map.merge(acc, parse_argument(arg))
     end)
+
+    Agent.start_link(fn -> options end, name: __MODULE__)
+  end
+
+  def clear_screen? do
+    Agent.get(__MODULE__, fn(options) ->
+      Map.fetch!(options, :clear_screen)
+    end)
   end
 
   def parse_argument("--clear-screen"), do: %{ clear_screen: true}
   def parse_argument(_), do: %{}
-
-  defp defaults do
-    %{ clear_screen: false}
-  end
 end