Fix the output of negative duration

Technically speaking, negative duration is not valid ISO 8601, but we need to
print it anyway. If `d` is a positive duration with the output `xxxxxxx`, then
the expected output of negative `-d` value is `-xxxxxxx`. I.e. the idea is to
print negative durations as positive with a leading minus sign.

Closes #18181.
This commit is contained in:
Vladimir Smola 2014-10-27 09:28:24 +07:00
parent a34b8dec69
commit 9bf82fa7ff

View File

@ -317,26 +317,29 @@ impl Div<i32,Duration> for Duration {
impl fmt::Show for Duration {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
let days = self.num_days();
let secs = self.secs - days * SECS_PER_DAY;
let hasdate = days != 0;
let hastime = (secs != 0 || self.nanos != 0) || !hasdate;
// technically speaking, negative duration is not valid ISO 8601,
// but we need to print it anyway.
let (abs, sign) = if self.secs < 0 { (-self, "-") } else { (*self, "") };
let days = abs.secs / SECS_PER_DAY;
let secs = abs.secs - days * SECS_PER_DAY;
let hasdate = days != 0;
let hastime = (secs != 0 || abs.nanos != 0) || !hasdate;
try!(write!(f, "{}P", sign));
try!(write!(f, "P"));
if hasdate {
// technically speaking the negative part is not the valid ISO 8601,
// but we need to print it anyway.
try!(write!(f, "{}D", days));
}
if hastime {
if self.nanos == 0 {
if abs.nanos == 0 {
try!(write!(f, "T{}S", secs));
} else if self.nanos % NANOS_PER_MILLI == 0 {
try!(write!(f, "T{}.{:03}S", secs, self.nanos / NANOS_PER_MILLI));
} else if self.nanos % NANOS_PER_MICRO == 0 {
try!(write!(f, "T{}.{:06}S", secs, self.nanos / NANOS_PER_MICRO));
} else if abs.nanos % NANOS_PER_MILLI == 0 {
try!(write!(f, "T{}.{:03}S", secs, abs.nanos / NANOS_PER_MILLI));
} else if abs.nanos % NANOS_PER_MICRO == 0 {
try!(write!(f, "T{}.{:06}S", secs, abs.nanos / NANOS_PER_MICRO));
} else {
try!(write!(f, "T{}.{:09}S", secs, self.nanos));
try!(write!(f, "T{}.{:09}S", secs, abs.nanos));
}
}
Ok(())
@ -540,13 +543,15 @@ mod tests {
let d: Duration = Zero::zero();
assert_eq!(d.to_string(), "PT0S".to_string());
assert_eq!(Duration::days(42).to_string(), "P42D".to_string());
assert_eq!(Duration::days(-42).to_string(), "P-42D".to_string());
assert_eq!(Duration::days(-42).to_string(), "-P42D".to_string());
assert_eq!(Duration::seconds(42).to_string(), "PT42S".to_string());
assert_eq!(Duration::milliseconds(42).to_string(), "PT0.042S".to_string());
assert_eq!(Duration::microseconds(42).to_string(), "PT0.000042S".to_string());
assert_eq!(Duration::nanoseconds(42).to_string(), "PT0.000000042S".to_string());
assert_eq!((Duration::days(7) + Duration::milliseconds(6543)).to_string(),
"P7DT6.543S".to_string());
assert_eq!(Duration::seconds(-86401).to_string(), "-P1DT1S".to_string());
assert_eq!(Duration::nanoseconds(-1).to_string(), "-PT0.000000001S".to_string());
// the format specifier should have no effect on `Duration`
assert_eq!(format!("{:30}", Duration::days(1) + Duration::milliseconds(2345)),