Pangram checker

You are encouraged to solve this task according to the task description, using any language you may know.
A pangram is a sentence that contains all the letters of the English alphabet at least once.

For example:   The quick brown fox jumps over the lazy dog.



Task

Write a function or method to check a sentence to see if it is a   pangram   (or not)   and show its use.



Related tasks

   determine if a string has all the same characters
   determine if a string has all unique characters


defmodule Pangram do
  def checker(str) do
    unused = Enum.to_list(?a..?z) -- to_char_list(String.downcase(str))
    Enum.empty?(unused)
  end
end
 
text = "The quick brown fox jumps over the lazy dog."
IO.puts "#{Pangram.checker(text)}\t#{text}"
text = (Enum.to_list(?A..?Z) -- 'Test') |> to_string
IO.puts "#{Pangram.checker(text)}\t#{text}"