defmodule Numbers do
  require Integer
  use Koans

  @intro "Numbers"

  koan "Are you odd?" do
    assert Integer.is_odd(3) == ___
  end

  koan "Actually you might be even" do
    assert Integer.is_even(4) == ___
  end

  koan "Let's grab the individual digits in a list" do 
    individual_digits = Integer.digits(58127)
    assert individual_digits == ___
  end

  koan "Oh no! I need it back together" do 
    number = Integer.undigits([1, 2, 3, 4])

    assert number == ___
  end

  koan "I think I need my number as a char" do 
    char_digit = Integer.to_char_list(7)

    assert char_digit == ___
  end

  koan "Actually I want my number as a string" do 
    string_digit = Integer.to_string(1234)

    assert string_digit == ___
  end

  koan "The meaning of life in hexidecimal is 2A!" do
    assert Integer.parse("2A", 16) == {___, ""}
  end

  koan "I don't want this decimal point, let's round up" do
    assert Float.ceil(34.25) == ___
  end

  koan "OK, I only want it to 1 decimal place" do
    assert Float.ceil(34.25, 1) == ___
  end

  koan "Rounding down is what I need" do
    assert Float.floor(99.99) == ___
  end

  koan "Rounding down to 2 decimal places" do
    assert Float.floor(12.345, 2) == ___
  end

  koan "Just want to parse to a float" do
    assert Float.parse("34.5") == {___, ""}
  end

  koan "Hmm, I want to parse this but it has some strings" do
    assert Float.parse("1 million dollars") == {___, " million dollars"}
  end

  koan "Round the number up or down for me" do
    assert Float.round(5.5) == ___
    assert Float.round(5.4) == ___
    assert Float.round(8.94, 1) == ___
    assert Float.round(-5.5674, 3) == ___
  end
end