lujanfernaud's solution to Pangram on the Elixir track

Instructions

Test suite

Solution

Determine if a sentence is a pangram. A pangram (Greek: παν γράμμα, pan gramma, "every letter") is a sentence using every letter of the alphabet at least once. The best known English pangram is:

The quick brown fox jumps over the lazy dog.

The alphabet used consists of ASCII letters a to z, inclusive, and is case insensitive. Input will not contain non-ASCII symbols.

Running tests

Execute the tests with:

$ mix test

Pending tests

In the test suites, all but the first test have been skipped.

Once you get a test passing, you can unskip the next one by commenting out the relevant @tag :pending with a # symbol.

For example:

# @tag :pending
test "shouting" do
  assert Bob.hey("WATCH OUT!") == "Whoa, chill out!"
end

Or, you can enable all the tests by commenting out the ExUnit.configure line in the test suite.

# ExUnit.configure exclude: :pending, trace: true

If you're stuck on something, it may help to look at some of the available resources out there where answers might be found.

Source

Wikipedia https://en.wikipedia.org/wiki/Pangram

Submitting Incomplete Solutions

It's possible to submit an incomplete solution so you can see how others have completed the exercise.

pangram_test.exs

defmodule PangramTest do
  use ExUnit.Case

  # @tag :pending
  test "empty sentence" do
    refute Pangram.pangram?("")
  end

  @tag :pending
  test "pangram with only lower case" do
    assert Pangram.pangram?("the quick brown fox jumps over the lazy dog")
  end

  @tag :pending
  test "missing character 'x'" do
    refute Pangram.pangram?("a quick movement of the enemy will jeopardize five gunboats")
  end

  @tag :pending
  test "another missing character 'x'" do
    refute Pangram.pangram?("the quick brown fish jumps over the lazy dog")
  end

  @tag :pending
  test "pangram with underscores" do
    assert Pangram.pangram?("the_quick_brown_fox_jumps_over_the_lazy_dog")
  end

  @tag :pending
  test "pangram with numbers" do
    assert Pangram.pangram?("the 1 quick brown fox jumps over the 2 lazy dogs")
  end

  @tag :pending
  test "missing letters replaced by numbers" do
    refute Pangram.pangram?("7h3 qu1ck brown fox jumps ov3r 7h3 lazy dog")
  end

  @tag :pending
  test "pangram with mixed case and punctuation" do
    assert Pangram.pangram?("Five quacking Zephyrs jolt my wax bed.")
  end

  @tag :pending
  test "pangram with non ascii characters" do
    assert Pangram.pangram?("Victor jagt zwölf Boxkämpfer quer über den großen Sylter Deich.")
  end

  @tag :pending
  test "pangram in alphabet other than ASCII" do
    refute Pangram.pangram?(
             "Широкая электрификация южных губерний даст мощный толчок подъёму сельского хозяйства."
           )
  end
end

test_helper.exs

ExUnit.start()
ExUnit.configure(exclude: :pending, trace: true)

defmodule Pangram do
  @doc """
  Determines if a word or sentence is a pangram.
  A pangram is a sentence using every letter of the alphabet at least once.

  Returns a boolean.

  ## Examples

  iex> Pangram.pangram?("the quick brown fox jumps over the lazy dog")
  true

  """

  @alphabet Enum.to_list(?a..?z)

  @spec pangram?(String.t()) :: boolean
  def pangram?(sentence) do
    (@alphabet -- characters_in(sentence)) |> Enum.empty?()
  end

  def characters_in(sentence), do: to_charlist(String.downcase(sentence))
end

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lujanfernaud's solution

to Pangram in the Elixir Track