Fix the spec for Hamming problem.

exercism · Jan 7, 2019 · 9cd3aae · 9cd3aae
1 parent f60625d
commit 9cd3aae
Showing 1 changed file with 1 addition and 1 deletion.
diff --git a/exercises/hamming/hamming.exs b/exercises/hamming/hamming.exs
@@ -7,7 +7,7 @@ defmodule Hamming do
   iex> Hamming.hamming_distance('AAGTCATA', 'TAGCGATC')
   {:ok, 4}
   """
-  @spec hamming_distance([char], [char]) :: non_neg_integer
+  @spec hamming_distance([char], [char]) :: {:ok, non_neg_integer} | {:error, String.t()}
   def hamming_distance(strand1, strand2) do
   end
 end