fizzbuzz in rex

call fizzbuzz 100
return

fizzbuzz:
    parse arg m
    do n=1 to m
        fb = maybe( dvd(n, 3), "Fizz" ) || maybe( dvd(n, 5), "Buzz" )
        if fb == '' then
            fb = n
        say fb
        end
    return

dvd:
    parse arg n, m
    return (n // m) == 0

maybe:
    parse arg p, t
    if p then
        return t
    return ''