Search exercise

no_worky.ex

  @doc """
  Parse data for a single line of the text file
  """
  def parse_line(line, _num, index) do
    String.downcase(line)
    |> String.to_charlist()
    |> Enum.with_index()
    |> Enum.chunk_while(
      {[], 0},
      fn {c, i}, {word, column} ->
        if c == ' ' do
          {:cont, {word, column}, {"", i}}
        else
          {:cont, {[word | c], column}}
        end
      end,
      fn
        [] -> {:cont, []}
        acc -> {:cont, Enum.reverse(acc), []}
      end
    )
    |> IO.inspect()
    |> Enum.reduce(index, fn {word, column}, acc ->
      Map.update(
        acc,
        word,
        [%Searchy.IndexEntry{line: line, column: column}],
        &(&1 ++ [%Searchy.IndexEntry{line: line, column: column}])
      )
    end)
  end

searchy.ex

defmodule Searchy do
  @moduledoc """
  Documentation for `Searchy`.
  """
  require IO

  defmodule IndexEntry do
    @moduledoc """
    An entry in the search index.
    """
    defstruct line: "", column: 0
  end

  @doc """
  Open the specified file and index all of the words
  """
  def build_index!(file) do
    File.open!(file)
    |> IO.stream(:line)
    |> Enum.map(&remove_punctuation(&1))
    |> Enum.with_index()
    |> Enum.reduce(%{}, &process_line(&1, &2))
  end

  @doc """
  Filter invalid characters from the provided line of text
  """
  def remove_punctuation(line) do
    String.replace(line, [".", ",", ";"], " ")
  end

  @doc """
  Process a line of text from the file
  """
  def process_line({line, num}, index), do: parse_line(line, num, index)

  @doc """
  Parse data for a single line of the text file
  """
  def parse_line(line, line_number, index) do
    String.downcase(line)
    |> String.split()
    |> Enum.reduce({index, 0}, fn word, {index, column} ->
      {Map.update(
         index,
         word,
         [%Searchy.IndexEntry{line: line_number, column: column}],
         &(&1 ++ [%Searchy.IndexEntry{line: line_number, column: column}])
       ), column + String.length(word) + 1}
    end)
    |> elem(0)
  end

  @doc """
  Search the index for the occurrences of word.
  """
  def search(index, word) do
    {:ok, Map.get(index, String.downcase(word), [])}
  end
end