Metric Conversion

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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Metric Conversion

You’re going to build an app to convert metric measurements such as millimeters, centimeters, meters, and kilometers according to the following table.

[
  [unit: :millimeter, value: 1, meter: 0.001],
  [unit: :centimeter, value: 1, meter: 0.01],
  [unit: :meter, value: 1, meter: 1],
  [unit: :kilometer, value: 1, meter: 1000]
]
|> Kino.DataTable.new()

Users provide values using {from_unit, value} tuples, and the desired unit to convert to.

Metric.convert({:centimeter, 100}, :meter)
1.0

The unit to convert from, and the unit to convert to can be either :millimeter, :centimeter, :meter, or :kilometer. The output should always be a float.

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

  @doc """
  Convert one measurement to another.
  We've used math values in the result

  ## Examples

    Convert unit to meters.

    iex> Metric.convert({:millimeter, 1}, :meter)
    0.001

    iex> Metric.convert({:centimeter, 1}, :meter)
    0.01

    iex> Metric.convert({:meter, 1}, :meter)
    1.0

    iex> Metric.convert({:kilometer, 1}, :meter)
    1000

    Convert meters to unit.

    iex> Metric.convert({:meter, 1}, :millimeter)
    1000.0

    iex> Metric.convert({:meter, 1}, :centimeter)
    100.0

    iex> Metric.convert({:meter, 1}, :meter)
    1.0

    iex> Metric.convert({:meter, 1}, :kilometer)
    0.001

    Convert unit to unit.

    iex> Metric.convert({:centimeter, 1000}, :kilometer)
    0.01

    iex> Metric.convert({:millimeter, 10}, :centimeter)
    1.0

    iex> Metric.convert({:kilometer, 10}, :centimeter)
    1000000
  """
  def convert(from, to) do
  end
end

Mark As Completed

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

save_name =
  case Path.basename(__DIR__) do
    "reading" -> "metric_conversion_reading"
    "exercises" -> "metric_conversion_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 metric-conversion-exercise
$ git add .
$ git commit -m "finish metric conversion exercise"
$ git push origin metric-conversion-exercise

Create a pull request from your metric-conversion-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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