Source code in the applescript programming language

-- gcd :: Int -> Int -> Int
on gcd(a, b)
    if b ≠ 0 then
        gcd(b, a mod b)
    else
        if a < 0 then
            -a
        else
            a
        end if
    end if
end gcd


on hcf(a, b)
    repeat until (b = 0)
        set x to a
        set a to b
        set b to x mod b
    end repeat
    
    if (a < 0) then return -a
    return a
end hcf