AjhBase36Test.x++

static void AjhBase36Test(Args _args)
{
    // ajh 2014-05-07: 611.23
    // adapted from http://en.wikipedia.org/wiki/Base_36.
    // note: handles non-negative integers only.
    #define.NBASE(36)
    #define.CLIST("0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ")

    int64 base36_decode(str base36_input)
    {
        int64 result = 0;
        real pow = 0;
        int i, pos;
        str c;

        for (i = strLen(base36_input); i > 0; i--)
        {
            c = subStr(base36_input, i, 1);
            pos = strScan(#CLIST, c, 1, #NBASE) - 1;
            if (pos == -1)
                return pos;  // error
            result += pos * power(#NBASE, pow);
            pow++;
        }
        return result;
    }
    str base36_encode(int64 input_num)
    {
        int64 work_num = input_num;
        str result = "";
        int digitidx;
        str c;

        do {
            digitidx = int642int(work_num mod #NBASE);
            c = subStr(#CLIST, digitidx + 1, 1);
            result += c;
            work_num = work_num div #NBASE;
        } while (work_num > 0);
        return strReverse(result);
    }

    print base36_decode("");
    print base36_decode("0");
    print base36_decode("A"); // 10
    print base36_decode("7PS"); // 10,000
    print base36_decode("255S"); // 100,000
    print base36_decode("!@#$"); // error
    print base36_encode(0);
    print base36_encode(123);
    print base36_encode(10000);
    print base36_encode(100000);
    pause;
}