# Document Tools ```elixir Mix.install([ {:jason, "~> 1.4"}, {:kino, "~> 0.9", override: true}, {:youtube, github: "brooklinjazz/youtube"}, {:hidden_cell, github: "brooklinjazz/hidden_cell"} ]) ``` ## Navigation <div style="display: flex; align-items: center; width: 100%; justify-content: space-between; font-size: 1rem; color: #61758a; background-color: #f0f5f9; height: 4rem; padding: 0 1rem; border-radius: 1rem;"> <div style="display: flex;"> <i class="ri-home-fill"></i> <a style="display: flex; color: #61758a; margin-left: 1rem;" href="../start.livemd">Home</a> </div> <div style="display: flex;"> <i class="ri-bug-fill"></i> <a style="display: flex; color: #61758a; margin-left: 1rem;" href="https://github.com/DockYard-Academy/curriculum/issues/new?assignees=&labels=&template=issue.md&title=Document Tools">Report An Issue</a> </div> <div style="display: flex;"> <i class="ri-arrow-left-fill"></i> <a style="display: flex; color: #61758a; margin-left: 1rem;" href="../exercises/file_system_todo_app.livemd">File System Todo</a> </div> <div style="display: flex;"> <a style="display: flex; color: #61758a; margin-right: 1rem;" href="../exercises/file_search.livemd">File Search</a> <i class="ri-arrow-right-fill"></i> </div> </div> ## Document Tools You're going to create a `Document` module which provides some convenient function for working with text files. Once you have a working solution, consider how you can optimize it to reduce how much of a file you load into memory. <details style="background-color: lightgreen; padding: 1rem; margin: 1rem 0;"> <summary>Example Solution</summary> ```elixir defmodule Document do def word_count(file_name) do File.stream!(file_name) |> Stream.map(fn line -> line |> String.split(" ", trim: true) |> Enum.count() end) |> Enum.sum() end def line_count(file_name) do file = File.open!(file_name) count = count_lines(file) File.close(file) count end defp count_lines(file, count \\ 0) do case IO.read(file, :line) do :eof -> count _ -> count_lines(file, count + 1) end end def add_line_numbers(file_name) do lined_content = File.stream!(file_name) |> Stream.with_index() |> Stream.map(fn {line, index} -> "#{index + 1}. #{line}" end) |> Enum.join("") File.write!(file_name, lined_content) end end ``` </details> ```elixir defmodule Document do @moduledoc """ Documentation for `Document` module. """ @doc ~S""" Count the number of words in a document. ## Examples Any sequence of characters separated by a space will be considered a word. iex> File.write("word_count.txt", "one two three") iex> Document.word_count("word_count.txt") 3 Ensure your solution ignores newline characters. iex> File.write("word_count.txt", "one\ntwo\nthree") iex> Document.word_count("word_count.txt") 3 """ def word_count(file_name) do end @doc ~S""" Count the number of words in a document. ## Examples iex> File.write("line_count.txt", "line1\nline2\nline3\n") iex> Document.line_count("line_count.txt") 3 """ def line_count(file_name) do end @doc ~S""" Add line numbers formatted as "X. rest of line" to an existing file. ## Examples iex> File.write("add_line_numbers.txt", "one\ntwo\nthree") iex> Document.add_line_numbers("add_line_numbers.txt") iex> File.read!("add_line_numbers.txt") "1. one\n2. two\n3. three" """ def add_line_numbers(file_name) do end end ``` ## Commit Your Progress DockYard Academy now recommends you use the latest [Release](https://github.com/DockYard-Academy/curriculum/releases) rather than forking or cloning our repository. Run `git status` to ensure there are no undesirable changes. Then run the following in your command line from the `curriculum` folder to commit your progress. ``` $ git add . $ git commit -m "finish Document Tools exercise" $ git push ``` We're proud to offer our open-source curriculum free of charge for anyone to learn from at their own pace. We also offer a paid course where you can learn from an instructor alongside a cohort of your peers. We will accept applications for the June-August 2023 cohort soon. ## Navigation <div style="display: flex; align-items: center; width: 100%; justify-content: space-between; font-size: 1rem; color: #61758a; background-color: #f0f5f9; height: 4rem; padding: 0 1rem; border-radius: 1rem;"> <div style="display: flex;"> <i class="ri-home-fill"></i> <a style="display: flex; color: #61758a; margin-left: 1rem;" href="../start.livemd">Home</a> </div> <div style="display: flex;"> <i class="ri-bug-fill"></i> <a style="display: flex; color: #61758a; margin-left: 1rem;" href="https://github.com/DockYard-Academy/curriculum/issues/new?assignees=&labels=&template=issue.md&title=Document Tools">Report An Issue</a> </div> <div style="display: flex;"> <i class="ri-arrow-left-fill"></i> <a style="display: flex; color: #61758a; margin-left: 1rem;" href="../exercises/file_system_todo_app.livemd">File System Todo</a> </div> <div style="display: flex;"> <a style="display: flex; color: #61758a; margin-right: 1rem;" href="../exercises/file_search.livemd">File Search</a> <i class="ri-arrow-right-fill"></i> </div> </div>