word_count

elixir/word-count/lib/word_count.ex

@@ -0,0 +1,17 @@
+defmodule WordCount do
+  @doc """
+  Count the number of words in the sentence.
+
+  Words are compared case-insensitively.
+  """
+  @spec count(String.t()) :: map
+  def count(sentence) do
+    sentence
+    |> String.split(~r/[\s,.:!?_]+/, trim: true)
+    |> Enum.reject(&String.match?(&1, ~r/[&@$%^]+/))
+    |> Enum.map(&String.trim(&1, "'"))
+    |> Enum.reduce(%{}, fn word, acc ->
+      Map.update(acc, String.downcase(word), 1, &(&1 + 1))
+    end)
+  end
+end