Add wc_2, small improvement step

2 files changed, 34 insertions, 0 deletions

diff --git a/src/code/2/wc_2.exs b/src/code/2/wc_2.exs
new file mode 100644
index 0000000..f7e97e9
--- /dev/null
+++ b/src/code/2/wc_2.exs
@@ -0,0 +1,29 @@
+defmodule WordCount do
+
+  defp stream_file(filename) do
+    File.stream!(filename)
+  end
+
+  defp tokenize_words(line) do
+    line |> Stream.flat_map(&String.split/1)
+  end
+
+  defp reduce_words(words) when is_list(words) do
+    Enum.reduce(words, %{}, &update_count/2)
+  end
+
+  defp update_count(word, acc) do
+    Map.update(acc, word, 1, &(&1 + 1))
+  end
+
+  def count_words(filename) do
+    stream_file(filename)
+    |> tokenize_words
+    |> Stream.map(&String.downcase/1)
+    |> Enum.to_list
+    |> reduce_words
+  end
+
+end
+
+WordCount.count_words("pg51353.txt") |> IO.inspect(limit: 20)
diff --git a/src/func-w-elixir.tex b/src/func-w-elixir.tex
index 8fcb41a..6f0ab9f 100644
--- a/src/func-w-elixir.tex
+++ b/src/func-w-elixir.tex
@@ -417,6 +417,11 @@ F_1 &= 1
 \lstinputlisting{code/2/wc.out}
 \end{frame}
 
+\begin{frame}[fragile]
+\frametitle{Improve Word Counting}
+\lstinputlisting[numbers=left,firstline=19,lastline=25]{code/2/wc_2.exs}
+\end{frame}
+
 \subsubsection{Parallel Map}
 \begin{frame}
 \frametitle{Parallel Map}