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


^$." "
[$999>][1000- "M"]#
 $899> [ 900-"CM"]?
 $499> [ 500- "D"]?
 $399> [ 400-"CD"]?
[$ 99>][ 100- "C"]#
 $ 89> [  90-"XC"]?
 $ 49> [  50- "L"]?
 $ 39> [  40-"XL"]?
[$  9>][  10- "X"]#
 $  8> [   9-"IX"]?
 $  4> [   5- "V"]?
 $  3> [   4-"IV"]?
[$    ][   1- "I"]#%