number_t sub_number(number_t a, number_t b)
{
number_t result;
int borrow, dif, i;
if (a.sign != b.sign) {
b.sign *= -1;
return add_number(a, b);
}
if (a.sign < 0 && b.sign < 0) {
a.sign = b.sign = 1;
return sub_number(b, a);
}
if (compare_number(a, b) < 0) {
result = sub_number(b, a);
if (! (result.digit_len == 2 && result.digit[0] == 0 && result.digit[1] == 0))
result.sign = -1;
return result;
}
result.sign = 1;
result.int_len = max(a.int_len, b.int_len);
result.digit_len = result.int_len + max(a.digit_len - a.int_len, b.digit_len - b.int_len);
borrow = 0;
for (i = result.digit_len - 1; i >= 0; i--) {
dif = -borrow + digit_at(a, result.int_len - i - 1) - digit_at(b, result.int_len - i - 1);
if (dif < 0) {
borrow = 1;
dif += 10;
} else
borrow = 0;
result.digit[i] = dif % 10;
}
return remove_zeros(result);
}
number_t add_number(number_t a, number_t b)
{
number_t result;
int sum, carry, i;
if (a.sign != b.sign) {
b.sign *= -1;
return sub_number(a, b);
}
result.sign = a.sign;
result.int_len = max(a.int_len, b.int_len) + 1;
result.digit_len = result.int_len + max(a.digit_len - a.int_len, b.digit_len - b.int_len);
carry = 0;
for (i = result.digit_len - 1; i >= 0; i--) {
sum = carry + digit_at(a, result.int_len - i - 1) + digit_at(b, result.int_len - i - 1);
result.digit[i] = sum % 10;
carry = sum / 10;
}
return remove_zeros(result);
}
/**
* time_from_isodate:
* @str: Date/time value in ISO 8601 format.
*
* Converts an ISO 8601 UTC time string into a time_t value.
*
* Return value: Time_t corresponding to the specified ISO string.
* Note that we only allow UTC times at present.
**/
time_t
time_from_isodate (const char *str)
{
struct icaltimetype tt = icaltime_null_time ();
icaltimezone *utc_zone;
int len, i;
g_return_val_if_fail (str != NULL, -1);
/* yyyymmdd[Thhmmss[Z]] */
len = strlen (str);
if (!(len == 8 || len == 15 || len == 16))
return -1;
for (i = 0; i < len; i++)
if (!((i != 8 && i != 15 && isdigit (str[i]))
|| (i == 8 && str[i] == 'T')
|| (i == 15 && str[i] == 'Z')))
return -1;
#define digit_at(x,y) (x[y] - '0')
tt.year = digit_at (str, 0) * 1000
+ digit_at (str, 1) * 100
+ digit_at (str, 2) * 10
+ digit_at (str, 3);
tt.month = digit_at (str, 4) * 10
+ digit_at (str, 5);
tt.day = digit_at (str, 6) * 10
+ digit_at (str, 7);
if (len > 8) {
tt.hour = digit_at (str, 9) * 10
+ digit_at (str, 10);
tt.minute = digit_at (str, 11) * 10
+ digit_at (str, 12);
tt.second = digit_at (str, 13) * 10
+ digit_at (str, 14);
}
utc_zone = icaltimezone_get_utc_timezone ();
return icaltime_as_timet_with_zone (tt, utc_zone);
}
time_t
time_from_isodate (char *str)
{
struct tm my_tm;
time_t t;
if (strlen (str) < 14)
return -1;
my_tm.tm_year = (digit_at (str, 0) * 1000 + digit_at (str, 1) * 100 +
digit_at (str, 2) * 10 + digit_at (str, 3)) - 1900;
my_tm.tm_mon = digit_at (str, 4) * 10 + digit_at (str, 5) - 1;
my_tm.tm_mday = digit_at (str, 6) * 10 + digit_at (str, 7);
my_tm.tm_hour = digit_at (str, 9) * 10 + digit_at (str, 10);
my_tm.tm_min = digit_at (str, 11) * 10 + digit_at (str, 12);
my_tm.tm_sec = digit_at (str, 13) * 10 + digit_at (str, 14);
my_tm.tm_isdst = -1;
t = mktime (&my_tm);
if (str [15] == 'Z')
#if defined(HAVE_TM_GMTOFF)
t -= my_tm.tm_gmtoff
#elsif defined(HAVE_TIMEZONE)
t -= timezone
#endif
;
return t;
}