Task

Create a function taking a positive integer as its parameter and returning a string containing the Roman numeral representation of that integer. Modern Roman numerals are written by expressing each digit separately, starting with the left most digit and skipping any digit with a value of zero.



In Roman numerals:

 1990 is rendered: 1000=M, 900=CM, 90=XC; resulting in MCMXC
 2008 is written as 2000=MM, 8=VIII; or MMVIII
 1666 uses each Roman symbol in descending order: MDCLXVI


a2r(a)=
  r = ""
  n = [["M","CM","D","CD","C","XC","L","XL","X","IX","V","IV","I"],[1000,900,500,400,100,90,50,40,10,9,5,4,1]]
  > i, 1..13
    > a!<n[i,2]
      r += n[i,1]
      a -= n[i,2]
    <
  <
  <= r
.
 
t = [1990,2008,1666]
> i, 1..#.size(t,1)
  #.output(t[i]," = ",a2r(t[i]))
<