Time Converting

Mix.install([
  {:jason, "~> 1.4"},
  {:kino, "~> 0.8.0", override: true},
  {:youtube, github: "brooklinjazz/youtube"},
  {:hidden_cell, github: "brooklinjazz/hidden_cell"}
])

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Time Converting

Often we have to convert seconds, minutes, hours, and days. You’re going to create a TimeConverter module which can handle all of this for us.

We’ll use the atoms :days, :hours, :minutes, or :seconds to represent days, hours, minutes, and seconds.

Example Solution

defmodule TimeConverter do
  def to_seconds(amount, unit) do
    case unit do
      :seconds -> amount
      :minutes -> amount * 60
      :hours -> amount * 60 * 60
      :days -> amount * 60 * 60 * 24
    end
  end

  def from_seconds(amount, unit) do
    case unit do
      :seconds -> amount * 1.0
      :minutes -> amount / 60
      :hours -> amount / 60 / 60
      :days -> amount / 60 / 60 / 24
    end
  end
end

Implement the TimeConverter.to_seconds/2 and TimeConverter.from_seconds/2 functions as documented.

defmodule TimeConverter do
  @moduledoc """
  Documentation for `TimeConverter`
  """

  @doc """
  Convert a unit of time to a number of seconds.

  ## Examples

    iex> TimeConverter.to_seconds(1, :seconds)
    1

    iex> TimeConverter.to_seconds(1, :minutes)
    60
    
    iex> TimeConverter.to_seconds(1, :hours)
    3600

    iex> TimeConverter.to_seconds(1, :days)
    86400

  """
  def to_seconds(amount, unit) do
  end

  @doc """
  Convert a number of seconds to a unit of time.
  Return a float, as these values will require division using `/`.

  ## Examples

    iex> TimeConverter.from_seconds(1, :seconds)
    1.0

    iex> TimeConverter.from_seconds(60, :minutes)
    1.0
    
    iex> TimeConverter.from_seconds(3600, :hours)
    1.0

    iex> TimeConverter.from_seconds(86400, :days)
    1.0

  """
  def from_seconds(amount, unit) do
  end
end

Mark As Completed

file_name = Path.basename(Regex.replace(~r/#.+/, __ENV__.file, ""), ".livemd")

save_name =
  case Path.basename(__DIR__) do
    "reading" -> "time_converting_reading"
    "exercises" -> "time_converting_exercise"
  end

progress_path = __DIR__ <> "/../progress.json"
existing_progress = File.read!(progress_path) |> Jason.decode!()

default = Map.get(existing_progress, save_name, false)

form =
  Kino.Control.form(
    [
      completed: input = Kino.Input.checkbox("Mark As Completed", default: default)
    ],
    report_changes: true
  )

Task.async(fn ->
  for %{data: %{completed: completed}} <- Kino.Control.stream(form) do
    File.write!(
      progress_path,
      Jason.encode!(Map.put(existing_progress, save_name, completed), pretty: true)
    )
  end
end)

form

Commit Your Progress

Run the following in your command line from the curriculum folder to track and save your progress in a Git commit. Ensure that you do not already have undesired or unrelated changes by running git status or by checking the source control tab in Visual Studio Code.

$ git checkout -b time-converting-exercise
$ git add .
$ git commit -m "finish time converting exercise"
$ git push origin time-converting-exercise

Create a pull request from your time-converting-exercise branch to your solutions branch. Please do not create a pull request to the DockYard Academy repository as this will spam our PR tracker.

DockYard Academy Students Only:

Notify your teacher by including @BrooklinJazz in your PR description to get feedback. You (or your teacher) may merge your PR into your solutions branch after review.

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