Transform an integer to a roman numeral

toRoman.fsx

#!/usr/bin/env fsharpi

let elements = [ "M", 1000; "CM", 900; "D", 500; "CD", 400; "C", 100; "XC", 90; "L", 50; "XL", 40; "X", 10; "IX", 9; "V", 5; "IV", 4; "I", 1 ]

let rec toRomanNumber (v : int) : string =
    if v >= 1 then
        let e, v' = elements |> List.find (snd >> (>=) v)
        e + toRomanNumber (v - v')
    else
        ""

for i = 1 to 100 do
    printfn "%i: %s" i (toRomanNumber i)