Another update from ingydotnet^djgoku

Task/Queue-Definition/Elixir/queue-definition.elixir

@@ -0,0 +1,12 @@
+defmodule Queue do
+  def new, do: {Queue, [], []}
+
+  def push({Queue, input, output}, x), do: {Queue, [x|input], output}
+
+  def pop({Queue, [], []}), do: (raise RuntimeError, message: "empty Queue")
+  def pop({Queue, input, []}), do: pop({Queue, [], Enum.reverse(input)})
+  def pop({Queue, input, [h|t]}), do: {h, {Queue, input, t}}
+
+  def empty?({Queue, [], []}), do: true
+  def empty?({Queue, _, _}), do: false
+end