Question

I want to mix roman numerals with arabic numerals when doing some math.

I would define some classes for each symbol

class I
end

class V
end

class X
end

Now I want to be able to say things like

5 + V   # results in 10
X + 12  # results in 22

But am not sure where to start.
I would have to define a method that tells ruby how 5 + V works, give each class a value, and when I say

I

I should get the value 1.

What kind of methods should I look at that allows me to treat X as the number 10?

Answer 1

Seems really simple to me:

V = 5
V + 1 #=> 6

If you want to show the result as roman numerals, I would extend the Fixnum class with a to_roman method:

class Fixnum
  def to_roman
    # I'll leave the implementation up to you
  end
end

With this you can do:

10.to_roman #=> "X"