proverb

elixir/proverb/lib/proverb.ex

@@ -0,0 +1,17 @@
+defmodule Proverb do
+  @doc """
+  Generate a proverb from a list of strings.
+  """
+  @spec recite(strings :: [String.t()]) :: String.t()
+  def recite([]), do: ""
+  def recite([one]), do: first_in_the_end(one)
+  def recite([head | tail]), do: Enum.join([first(head), recite_proverb(tail), first_in_the_end(head)])
+    
+  defp recite_proverb([last]), do: last(last)
+  defp recite_proverb([middle | tail]), do: middle(middle) <> " " <> recite_proverb(tail)
+
+  defp first(first), do: "For want of a #{first} "
+  defp middle(middle), do: "the #{middle} was lost.\nFor want of a #{middle}"
+  defp last(last), do: "the #{last} was lost.\n"
+  defp first_in_the_end(first), do: "And all for the want of a #{first}.\n"
+end