1// This is a part of Chrono.
2// See README.md and LICENSE.txt for details.
3
4//! Date and time formatting routines.
5
6#[cfg(all(feature = "alloc", not(feature = "std"), not(test)))]
7use alloc::string::{String, ToString};
8#[cfg(feature = "alloc")]
9use core::borrow::Borrow;
10#[cfg(feature = "alloc")]
11use core::fmt::Display;
12use core::fmt::{self, Write};
13
14#[cfg(feature = "alloc")]
15use crate::offset::Offset;
16#[cfg(any(feature = "alloc", feature = "serde"))]
17use crate::{Datelike, FixedOffset, NaiveDateTime, Timelike};
18#[cfg(feature = "alloc")]
19use crate::{NaiveDate, NaiveTime, Weekday};
20
21#[cfg(feature = "alloc")]
22use super::locales;
23#[cfg(any(feature = "alloc", feature = "serde"))]
24use super::{Colons, OffsetFormat, OffsetPrecision, Pad};
25#[cfg(feature = "alloc")]
26use super::{Fixed, InternalFixed, InternalInternal, Item, Numeric};
27#[cfg(feature = "alloc")]
28use locales::*;
29
30/// A *temporary* object which can be used as an argument to `format!` or others.
31/// This is normally constructed via `format` methods of each date and time type.
32#[cfg(feature = "alloc")]
33#[derive(Debug)]
34pub struct DelayedFormat<I> {
35 /// The date view, if any.
36 date: Option<NaiveDate>,
37 /// The time view, if any.
38 time: Option<NaiveTime>,
39 /// The name and local-to-UTC difference for the offset (timezone), if any.
40 off: Option<(String, FixedOffset)>,
41 /// An iterator returning formatting items.
42 items: I,
43 /// Locale used for text.
44 /// ZST if the `unstable-locales` feature is not enabled.
45 locale: Locale,
46}
47
48#[cfg(feature = "alloc")]
49impl<'a, I: Iterator<Item = B> + Clone, B: Borrow<Item<'a>>> DelayedFormat<I> {
50 /// Makes a new `DelayedFormat` value out of local date and time.
51 #[must_use]
52 pub fn new(date: Option<NaiveDate>, time: Option<NaiveTime>, items: I) -> DelayedFormat<I> {
53 DelayedFormat { date, time, off: None, items, locale: default_locale() }
54 }
55
56 /// Makes a new `DelayedFormat` value out of local date and time and UTC offset.
57 #[must_use]
58 pub fn new_with_offset<Off>(
59 date: Option<NaiveDate>,
60 time: Option<NaiveTime>,
61 offset: &Off,
62 items: I,
63 ) -> DelayedFormat<I>
64 where
65 Off: Offset + Display,
66 {
67 let name_and_diff = (offset.to_string(), offset.fix());
68 DelayedFormat { date, time, off: Some(name_and_diff), items, locale: default_locale() }
69 }
70
71 /// Makes a new `DelayedFormat` value out of local date and time and locale.
72 #[cfg(feature = "unstable-locales")]
73 #[must_use]
74 pub fn new_with_locale(
75 date: Option<NaiveDate>,
76 time: Option<NaiveTime>,
77 items: I,
78 locale: Locale,
79 ) -> DelayedFormat<I> {
80 DelayedFormat { date, time, off: None, items, locale }
81 }
82
83 /// Makes a new `DelayedFormat` value out of local date and time, UTC offset and locale.
84 #[cfg(feature = "unstable-locales")]
85 #[must_use]
86 pub fn new_with_offset_and_locale<Off>(
87 date: Option<NaiveDate>,
88 time: Option<NaiveTime>,
89 offset: &Off,
90 items: I,
91 locale: Locale,
92 ) -> DelayedFormat<I>
93 where
94 Off: Offset + Display,
95 {
96 let name_and_diff = (offset.to_string(), offset.fix());
97 DelayedFormat { date, time, off: Some(name_and_diff), items, locale }
98 }
99
100 /// Formats `DelayedFormat` into a `core::fmt::Write` instance.
101 /// # Errors
102 /// This function returns a `core::fmt::Error` if formatting into the `core::fmt::Write` instance fails.
103 ///
104 /// # Example
105 /// ### Writing to a String
106 /// ```
107 /// let dt = chrono::DateTime::from_timestamp(1643723400, 123456789).unwrap();
108 /// let df = dt.format("%Y-%m-%d %H:%M:%S%.9f");
109 /// let mut buffer = String::new();
110 /// let _ = df.write_to(&mut buffer);
111 /// ```
112 pub fn write_to(&self, w: &mut impl Write) -> fmt::Result {
113 for item in self.items.clone() {
114 match *item.borrow() {
115 Item::Literal(s) | Item::Space(s) => w.write_str(s),
116 #[cfg(feature = "alloc")]
117 Item::OwnedLiteral(ref s) | Item::OwnedSpace(ref s) => w.write_str(s),
118 Item::Numeric(ref spec, pad) => self.format_numeric(w, spec, pad),
119 Item::Fixed(ref spec) => self.format_fixed(w, spec),
120 Item::Error => Err(fmt::Error),
121 }?;
122 }
123 Ok(())
124 }
125
126 #[cfg(feature = "alloc")]
127 fn format_numeric(&self, w: &mut impl Write, spec: &Numeric, pad: Pad) -> fmt::Result {
128 use self::Numeric::*;
129
130 fn write_one(w: &mut impl Write, v: u8) -> fmt::Result {
131 w.write_char((b'0' + v) as char)
132 }
133
134 fn write_two(w: &mut impl Write, v: u8, pad: Pad) -> fmt::Result {
135 let ones = b'0' + v % 10;
136 match (v / 10, pad) {
137 (0, Pad::None) => {}
138 (0, Pad::Space) => w.write_char(' ')?,
139 (tens, _) => w.write_char((b'0' + tens) as char)?,
140 }
141 w.write_char(ones as char)
142 }
143
144 #[inline]
145 fn write_year(w: &mut impl Write, year: i32, pad: Pad) -> fmt::Result {
146 if (1000..=9999).contains(&year) {
147 // fast path
148 write_hundreds(w, (year / 100) as u8)?;
149 write_hundreds(w, (year % 100) as u8)
150 } else {
151 write_n(w, 4, year as i64, pad, !(0..10_000).contains(&year))
152 }
153 }
154
155 fn write_n(
156 w: &mut impl Write,
157 n: usize,
158 v: i64,
159 pad: Pad,
160 always_sign: bool,
161 ) -> fmt::Result {
162 if always_sign {
163 match pad {
164 Pad::None => write!(w, "{:+}", v),
165 Pad::Zero => write!(w, "{:+01$}", v, n + 1),
166 Pad::Space => write!(w, "{:+1$}", v, n + 1),
167 }
168 } else {
169 match pad {
170 Pad::None => write!(w, "{}", v),
171 Pad::Zero => write!(w, "{:01$}", v, n),
172 Pad::Space => write!(w, "{:1$}", v, n),
173 }
174 }
175 }
176
177 match (spec, self.date, self.time) {
178 (Year, Some(d), _) => write_year(w, d.year(), pad),
179 (YearDiv100, Some(d), _) => write_two(w, d.year().div_euclid(100) as u8, pad),
180 (YearMod100, Some(d), _) => write_two(w, d.year().rem_euclid(100) as u8, pad),
181 (IsoYear, Some(d), _) => write_year(w, d.iso_week().year(), pad),
182 (IsoYearDiv100, Some(d), _) => {
183 write_two(w, d.iso_week().year().div_euclid(100) as u8, pad)
184 }
185 (IsoYearMod100, Some(d), _) => {
186 write_two(w, d.iso_week().year().rem_euclid(100) as u8, pad)
187 }
188 (Quarter, Some(d), _) => write_one(w, d.quarter() as u8),
189 (Month, Some(d), _) => write_two(w, d.month() as u8, pad),
190 (Day, Some(d), _) => write_two(w, d.day() as u8, pad),
191 (WeekFromSun, Some(d), _) => write_two(w, d.weeks_from(Weekday::Sun) as u8, pad),
192 (WeekFromMon, Some(d), _) => write_two(w, d.weeks_from(Weekday::Mon) as u8, pad),
193 (IsoWeek, Some(d), _) => write_two(w, d.iso_week().week() as u8, pad),
194 (NumDaysFromSun, Some(d), _) => write_one(w, d.weekday().num_days_from_sunday() as u8),
195 (WeekdayFromMon, Some(d), _) => write_one(w, d.weekday().number_from_monday() as u8),
196 (Ordinal, Some(d), _) => write_n(w, 3, d.ordinal() as i64, pad, false),
197 (Hour, _, Some(t)) => write_two(w, t.hour() as u8, pad),
198 (Hour12, _, Some(t)) => write_two(w, t.hour12().1 as u8, pad),
199 (Minute, _, Some(t)) => write_two(w, t.minute() as u8, pad),
200 (Second, _, Some(t)) => {
201 write_two(w, (t.second() + t.nanosecond() / 1_000_000_000) as u8, pad)
202 }
203 (Nanosecond, _, Some(t)) => {
204 write_n(w, 9, (t.nanosecond() % 1_000_000_000) as i64, pad, false)
205 }
206 (Timestamp, Some(d), Some(t)) => {
207 let offset = self.off.as_ref().map(|(_, o)| i64::from(o.local_minus_utc()));
208 let timestamp = d.and_time(t).and_utc().timestamp() - offset.unwrap_or(0);
209 write_n(w, 9, timestamp, pad, false)
210 }
211 (Internal(_), _, _) => Ok(()), // for future expansion
212 _ => Err(fmt::Error), // insufficient arguments for given format
213 }
214 }
215
216 #[cfg(feature = "alloc")]
217 fn format_fixed(&self, w: &mut impl Write, spec: &Fixed) -> fmt::Result {
218 use Fixed::*;
219 use InternalInternal::*;
220
221 match (spec, self.date, self.time, self.off.as_ref()) {
222 (ShortMonthName, Some(d), _, _) => {
223 w.write_str(short_months(self.locale)[d.month0() as usize])
224 }
225 (LongMonthName, Some(d), _, _) => {
226 w.write_str(long_months(self.locale)[d.month0() as usize])
227 }
228 (ShortWeekdayName, Some(d), _, _) => w.write_str(
229 short_weekdays(self.locale)[d.weekday().num_days_from_sunday() as usize],
230 ),
231 (LongWeekdayName, Some(d), _, _) => {
232 w.write_str(long_weekdays(self.locale)[d.weekday().num_days_from_sunday() as usize])
233 }
234 (LowerAmPm, _, Some(t), _) => {
235 let ampm = if t.hour12().0 { am_pm(self.locale)[1] } else { am_pm(self.locale)[0] };
236 for c in ampm.chars().flat_map(|c| c.to_lowercase()) {
237 w.write_char(c)?
238 }
239 Ok(())
240 }
241 (UpperAmPm, _, Some(t), _) => {
242 let ampm = if t.hour12().0 { am_pm(self.locale)[1] } else { am_pm(self.locale)[0] };
243 w.write_str(ampm)
244 }
245 (Nanosecond, _, Some(t), _) => {
246 let nano = t.nanosecond() % 1_000_000_000;
247 if nano == 0 {
248 Ok(())
249 } else {
250 w.write_str(decimal_point(self.locale))?;
251 if nano % 1_000_000 == 0 {
252 write!(w, "{:03}", nano / 1_000_000)
253 } else if nano % 1_000 == 0 {
254 write!(w, "{:06}", nano / 1_000)
255 } else {
256 write!(w, "{:09}", nano)
257 }
258 }
259 }
260 (Nanosecond3, _, Some(t), _) => {
261 w.write_str(decimal_point(self.locale))?;
262 write!(w, "{:03}", t.nanosecond() / 1_000_000 % 1000)
263 }
264 (Nanosecond6, _, Some(t), _) => {
265 w.write_str(decimal_point(self.locale))?;
266 write!(w, "{:06}", t.nanosecond() / 1_000 % 1_000_000)
267 }
268 (Nanosecond9, _, Some(t), _) => {
269 w.write_str(decimal_point(self.locale))?;
270 write!(w, "{:09}", t.nanosecond() % 1_000_000_000)
271 }
272 (Internal(InternalFixed { val: Nanosecond3NoDot }), _, Some(t), _) => {
273 write!(w, "{:03}", t.nanosecond() / 1_000_000 % 1_000)
274 }
275 (Internal(InternalFixed { val: Nanosecond6NoDot }), _, Some(t), _) => {
276 write!(w, "{:06}", t.nanosecond() / 1_000 % 1_000_000)
277 }
278 (Internal(InternalFixed { val: Nanosecond9NoDot }), _, Some(t), _) => {
279 write!(w, "{:09}", t.nanosecond() % 1_000_000_000)
280 }
281 (TimezoneName, _, _, Some((tz_name, _))) => write!(w, "{}", tz_name),
282 (TimezoneOffset | TimezoneOffsetZ, _, _, Some((_, off))) => {
283 let offset_format = OffsetFormat {
284 precision: OffsetPrecision::Minutes,
285 colons: Colons::Maybe,
286 allow_zulu: *spec == TimezoneOffsetZ,
287 padding: Pad::Zero,
288 };
289 offset_format.format(w, *off)
290 }
291 (TimezoneOffsetColon | TimezoneOffsetColonZ, _, _, Some((_, off))) => {
292 let offset_format = OffsetFormat {
293 precision: OffsetPrecision::Minutes,
294 colons: Colons::Colon,
295 allow_zulu: *spec == TimezoneOffsetColonZ,
296 padding: Pad::Zero,
297 };
298 offset_format.format(w, *off)
299 }
300 (TimezoneOffsetDoubleColon, _, _, Some((_, off))) => {
301 let offset_format = OffsetFormat {
302 precision: OffsetPrecision::Seconds,
303 colons: Colons::Colon,
304 allow_zulu: false,
305 padding: Pad::Zero,
306 };
307 offset_format.format(w, *off)
308 }
309 (TimezoneOffsetTripleColon, _, _, Some((_, off))) => {
310 let offset_format = OffsetFormat {
311 precision: OffsetPrecision::Hours,
312 colons: Colons::None,
313 allow_zulu: false,
314 padding: Pad::Zero,
315 };
316 offset_format.format(w, *off)
317 }
318 (RFC2822, Some(d), Some(t), Some((_, off))) => {
319 write_rfc2822(w, crate::NaiveDateTime::new(d, t), *off)
320 }
321 (RFC3339, Some(d), Some(t), Some((_, off))) => write_rfc3339(
322 w,
323 crate::NaiveDateTime::new(d, t),
324 *off,
325 SecondsFormat::AutoSi,
326 false,
327 ),
328 _ => Err(fmt::Error), // insufficient arguments for given format
329 }
330 }
331}
332
333#[cfg(feature = "alloc")]
334impl<'a, I: Iterator<Item = B> + Clone, B: Borrow<Item<'a>>> Display for DelayedFormat<I> {
335 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
336 let mut result: String = String::new();
337 self.write_to(&mut result)?;
338 f.pad(&result)
339 }
340}
341
342/// Tries to format given arguments with given formatting items.
343/// Internally used by `DelayedFormat`.
344#[cfg(feature = "alloc")]
345#[deprecated(since = "0.4.32", note = "Use DelayedFormat::fmt or DelayedFormat::write_to instead")]
346pub fn format<'a, I, B>(
347 w: &mut fmt::Formatter,
348 date: Option<&NaiveDate>,
349 time: Option<&NaiveTime>,
350 off: Option<&(String, FixedOffset)>,
351 items: I,
352) -> fmt::Result
353where
354 I: Iterator<Item = B> + Clone,
355 B: Borrow<Item<'a>>,
356{
357 DelayedFormat {
358 date: date.copied(),
359 time: time.copied(),
360 off: off.cloned(),
361 items,
362 locale: default_locale(),
363 }
364 .fmt(w)
365}
366
367/// Formats single formatting item
368#[cfg(feature = "alloc")]
369#[deprecated(since = "0.4.32", note = "Use DelayedFormat::fmt or DelayedFormat::write_to instead")]
370pub fn format_item(
371 w: &mut fmt::Formatter,
372 date: Option<&NaiveDate>,
373 time: Option<&NaiveTime>,
374 off: Option<&(String, FixedOffset)>,
375 item: &Item<'_>,
376) -> fmt::Result {
377 DelayedFormat {
378 date: date.copied(),
379 time: time.copied(),
380 off: off.cloned(),
381 items: [item].into_iter(),
382 locale: default_locale(),
383 }
384 .fmt(w)
385}
386
387#[cfg(any(feature = "alloc", feature = "serde"))]
388impl OffsetFormat {
389 /// Writes an offset from UTC with the format defined by `self`.
390 fn format(&self, w: &mut impl Write, off: FixedOffset) -> fmt::Result {
391 let off = off.local_minus_utc();
392 if self.allow_zulu && off == 0 {
393 w.write_char('Z')?;
394 return Ok(());
395 }
396 let (sign, off) = if off < 0 { ('-', -off) } else { ('+', off) };
397
398 let hours;
399 let mut mins = 0;
400 let mut secs = 0;
401 let precision = match self.precision {
402 OffsetPrecision::Hours => {
403 // Minutes and seconds are simply truncated
404 hours = (off / 3600) as u8;
405 OffsetPrecision::Hours
406 }
407 OffsetPrecision::Minutes | OffsetPrecision::OptionalMinutes => {
408 // Round seconds to the nearest minute.
409 let minutes = (off + 30) / 60;
410 mins = (minutes % 60) as u8;
411 hours = (minutes / 60) as u8;
412 if self.precision == OffsetPrecision::OptionalMinutes && mins == 0 {
413 OffsetPrecision::Hours
414 } else {
415 OffsetPrecision::Minutes
416 }
417 }
418 OffsetPrecision::Seconds
419 | OffsetPrecision::OptionalSeconds
420 | OffsetPrecision::OptionalMinutesAndSeconds => {
421 let minutes = off / 60;
422 secs = (off % 60) as u8;
423 mins = (minutes % 60) as u8;
424 hours = (minutes / 60) as u8;
425 if self.precision != OffsetPrecision::Seconds && secs == 0 {
426 if self.precision == OffsetPrecision::OptionalMinutesAndSeconds && mins == 0 {
427 OffsetPrecision::Hours
428 } else {
429 OffsetPrecision::Minutes
430 }
431 } else {
432 OffsetPrecision::Seconds
433 }
434 }
435 };
436 let colons = self.colons == Colons::Colon;
437
438 if hours < 10 {
439 if self.padding == Pad::Space {
440 w.write_char(' ')?;
441 }
442 w.write_char(sign)?;
443 if self.padding == Pad::Zero {
444 w.write_char('0')?;
445 }
446 w.write_char((b'0' + hours) as char)?;
447 } else {
448 w.write_char(sign)?;
449 write_hundreds(w, hours)?;
450 }
451 if let OffsetPrecision::Minutes | OffsetPrecision::Seconds = precision {
452 if colons {
453 w.write_char(':')?;
454 }
455 write_hundreds(w, mins)?;
456 }
457 if let OffsetPrecision::Seconds = precision {
458 if colons {
459 w.write_char(':')?;
460 }
461 write_hundreds(w, secs)?;
462 }
463 Ok(())
464 }
465}
466
467/// Specific formatting options for seconds. This may be extended in the
468/// future, so exhaustive matching in external code is not recommended.
469///
470/// See the `TimeZone::to_rfc3339_opts` function for usage.
471#[derive(Clone, Copy, Debug, Eq, PartialEq, Hash)]
472#[allow(clippy::manual_non_exhaustive)]
473pub enum SecondsFormat {
474 /// Format whole seconds only, with no decimal point nor subseconds.
475 Secs,
476
477 /// Use fixed 3 subsecond digits. This corresponds to [Fixed::Nanosecond3].
478 Millis,
479
480 /// Use fixed 6 subsecond digits. This corresponds to [Fixed::Nanosecond6].
481 Micros,
482
483 /// Use fixed 9 subsecond digits. This corresponds to [Fixed::Nanosecond9].
484 Nanos,
485
486 /// Automatically select one of `Secs`, `Millis`, `Micros`, or `Nanos` to display all available
487 /// non-zero sub-second digits. This corresponds to [Fixed::Nanosecond].
488 AutoSi,
489
490 // Do not match against this.
491 #[doc(hidden)]
492 __NonExhaustive,
493}
494
495/// Writes the date, time and offset to the string. same as `%Y-%m-%dT%H:%M:%S%.f%:z`
496#[inline]
497#[cfg(any(feature = "alloc", feature = "serde"))]
498pub(crate) fn write_rfc3339(
499 w: &mut impl Write,
500 dt: NaiveDateTime,
501 off: FixedOffset,
502 secform: SecondsFormat,
503 use_z: bool,
504) -> fmt::Result {
505 let year = dt.date().year();
506 if (0..=9999).contains(&year) {
507 write_hundreds(w, (year / 100) as u8)?;
508 write_hundreds(w, (year % 100) as u8)?;
509 } else {
510 // ISO 8601 requires the explicit sign for out-of-range years
511 write!(w, "{:+05}", year)?;
512 }
513 w.write_char('-')?;
514 write_hundreds(w, dt.date().month() as u8)?;
515 w.write_char('-')?;
516 write_hundreds(w, dt.date().day() as u8)?;
517
518 w.write_char('T')?;
519
520 let (hour, min, mut sec) = dt.time().hms();
521 let mut nano = dt.nanosecond();
522 if nano >= 1_000_000_000 {
523 sec += 1;
524 nano -= 1_000_000_000;
525 }
526 write_hundreds(w, hour as u8)?;
527 w.write_char(':')?;
528 write_hundreds(w, min as u8)?;
529 w.write_char(':')?;
530 let sec = sec;
531 write_hundreds(w, sec as u8)?;
532
533 match secform {
534 SecondsFormat::Secs => {}
535 SecondsFormat::Millis => write!(w, ".{:03}", nano / 1_000_000)?,
536 SecondsFormat::Micros => write!(w, ".{:06}", nano / 1000)?,
537 SecondsFormat::Nanos => write!(w, ".{:09}", nano)?,
538 SecondsFormat::AutoSi => {
539 if nano == 0 {
540 } else if nano % 1_000_000 == 0 {
541 write!(w, ".{:03}", nano / 1_000_000)?
542 } else if nano % 1_000 == 0 {
543 write!(w, ".{:06}", nano / 1_000)?
544 } else {
545 write!(w, ".{:09}", nano)?
546 }
547 }
548 SecondsFormat::__NonExhaustive => unreachable!(),
549 };
550
551 OffsetFormat {
552 precision: OffsetPrecision::Minutes,
553 colons: Colons::Colon,
554 allow_zulu: use_z,
555 padding: Pad::Zero,
556 }
557 .format(w, off)
558}
559
560#[cfg(feature = "alloc")]
561/// write datetimes like `Tue, 1 Jul 2003 10:52:37 +0200`, same as `%a, %d %b %Y %H:%M:%S %z`
562pub(crate) fn write_rfc2822(
563 w: &mut impl Write,
564 dt: NaiveDateTime,
565 off: FixedOffset,
566) -> fmt::Result {
567 let year = dt.year();
568 // RFC2822 is only defined on years 0 through 9999
569 if !(0..=9999).contains(&year) {
570 return Err(fmt::Error);
571 }
572
573 let english = default_locale();
574
575 w.write_str(short_weekdays(english)[dt.weekday().num_days_from_sunday() as usize])?;
576 w.write_str(", ")?;
577 let day = dt.day();
578 if day < 10 {
579 w.write_char((b'0' + day as u8) as char)?;
580 } else {
581 write_hundreds(w, day as u8)?;
582 }
583 w.write_char(' ')?;
584 w.write_str(short_months(english)[dt.month0() as usize])?;
585 w.write_char(' ')?;
586 write_hundreds(w, (year / 100) as u8)?;
587 write_hundreds(w, (year % 100) as u8)?;
588 w.write_char(' ')?;
589
590 let (hour, min, sec) = dt.time().hms();
591 write_hundreds(w, hour as u8)?;
592 w.write_char(':')?;
593 write_hundreds(w, min as u8)?;
594 w.write_char(':')?;
595 let sec = sec + dt.nanosecond() / 1_000_000_000;
596 write_hundreds(w, sec as u8)?;
597 w.write_char(' ')?;
598 OffsetFormat {
599 precision: OffsetPrecision::Minutes,
600 colons: Colons::None,
601 allow_zulu: false,
602 padding: Pad::Zero,
603 }
604 .format(w, off)
605}
606
607/// Equivalent to `{:02}` formatting for n < 100.
608pub(crate) fn write_hundreds(w: &mut impl Write, n: u8) -> fmt::Result {
609 if n >= 100 {
610 return Err(fmt::Error);
611 }
612
613 let tens: u8 = b'0' + n / 10;
614 let ones: u8 = b'0' + n % 10;
615 w.write_char(tens as char)?;
616 w.write_char(ones as char)
617}
618
619#[cfg(test)]
620#[cfg(feature = "alloc")]
621mod tests {
622 use super::{Colons, OffsetFormat, OffsetPrecision, Pad};
623 use crate::FixedOffset;
624 #[cfg(feature = "alloc")]
625 use crate::{NaiveDate, NaiveTime, TimeZone, Timelike, Utc};
626
627 #[cfg(feature = "alloc")]
628 #[test]
629 fn test_delayed_write_to() {
630 let dt = crate::DateTime::from_timestamp(1643723400, 123456789).unwrap();
631 let df = dt.format("%Y-%m-%d %H:%M:%S%.9f");
632
633 let mut dt_str = String::new();
634
635 df.write_to(&mut dt_str).unwrap();
636 assert_eq!(dt_str, "2022-02-01 13:50:00.123456789");
637 }
638
639 #[cfg(all(feature = "std", feature = "unstable-locales", feature = "alloc"))]
640 #[test]
641 fn test_with_locale_delayed_write_to() {
642 use crate::DateTime;
643 use crate::format::locales::Locale;
644
645 let dt = DateTime::from_timestamp(1643723400, 123456789).unwrap();
646 let df = dt.format_localized("%A, %B %d, %Y", Locale::ja_JP);
647
648 let mut dt_str = String::new();
649
650 df.write_to(&mut dt_str).unwrap();
651
652 assert_eq!(dt_str, "火曜日, 2月 01, 2022");
653 }
654
655 #[test]
656 #[cfg(feature = "alloc")]
657 fn test_date_format() {
658 let d = NaiveDate::from_ymd_opt(2012, 3, 4).unwrap();
659 assert_eq!(d.format("%Y,%C,%y,%G,%g").to_string(), "2012,20,12,2012,12");
660 assert_eq!(d.format("%m,%b,%h,%B").to_string(), "03,Mar,Mar,March");
661 assert_eq!(d.format("%q").to_string(), "1");
662 assert_eq!(d.format("%d,%e").to_string(), "04, 4");
663 assert_eq!(d.format("%U,%W,%V").to_string(), "10,09,09");
664 assert_eq!(d.format("%a,%A,%w,%u").to_string(), "Sun,Sunday,0,7");
665 assert_eq!(d.format("%j").to_string(), "064"); // since 2012 is a leap year
666 assert_eq!(d.format("%D,%x").to_string(), "03/04/12,03/04/12");
667 assert_eq!(d.format("%F").to_string(), "2012-03-04");
668 assert_eq!(d.format("%v").to_string(), " 4-Mar-2012");
669 assert_eq!(d.format("%t%n%%%n%t").to_string(), "\t\n%\n\t");
670
671 // non-four-digit years
672 assert_eq!(
673 NaiveDate::from_ymd_opt(12345, 1, 1).unwrap().format("%Y").to_string(),
674 "+12345"
675 );
676 assert_eq!(NaiveDate::from_ymd_opt(1234, 1, 1).unwrap().format("%Y").to_string(), "1234");
677 assert_eq!(NaiveDate::from_ymd_opt(123, 1, 1).unwrap().format("%Y").to_string(), "0123");
678 assert_eq!(NaiveDate::from_ymd_opt(12, 1, 1).unwrap().format("%Y").to_string(), "0012");
679 assert_eq!(NaiveDate::from_ymd_opt(1, 1, 1).unwrap().format("%Y").to_string(), "0001");
680 assert_eq!(NaiveDate::from_ymd_opt(0, 1, 1).unwrap().format("%Y").to_string(), "0000");
681 assert_eq!(NaiveDate::from_ymd_opt(-1, 1, 1).unwrap().format("%Y").to_string(), "-0001");
682 assert_eq!(NaiveDate::from_ymd_opt(-12, 1, 1).unwrap().format("%Y").to_string(), "-0012");
683 assert_eq!(NaiveDate::from_ymd_opt(-123, 1, 1).unwrap().format("%Y").to_string(), "-0123");
684 assert_eq!(NaiveDate::from_ymd_opt(-1234, 1, 1).unwrap().format("%Y").to_string(), "-1234");
685 assert_eq!(
686 NaiveDate::from_ymd_opt(-12345, 1, 1).unwrap().format("%Y").to_string(),
687 "-12345"
688 );
689
690 // corner cases
691 assert_eq!(
692 NaiveDate::from_ymd_opt(2007, 12, 31).unwrap().format("%G,%g,%U,%W,%V").to_string(),
693 "2008,08,52,53,01"
694 );
695 assert_eq!(
696 NaiveDate::from_ymd_opt(2010, 1, 3).unwrap().format("%G,%g,%U,%W,%V").to_string(),
697 "2009,09,01,00,53"
698 );
699 }
700
701 #[test]
702 #[cfg(feature = "alloc")]
703 fn test_time_format() {
704 let t = NaiveTime::from_hms_nano_opt(3, 5, 7, 98765432).unwrap();
705 assert_eq!(t.format("%H,%k,%I,%l,%P,%p").to_string(), "03, 3,03, 3,am,AM");
706 assert_eq!(t.format("%M").to_string(), "05");
707 assert_eq!(t.format("%S,%f,%.f").to_string(), "07,098765432,.098765432");
708 assert_eq!(t.format("%.3f,%.6f,%.9f").to_string(), ".098,.098765,.098765432");
709 assert_eq!(t.format("%R").to_string(), "03:05");
710 assert_eq!(t.format("%T,%X").to_string(), "03:05:07,03:05:07");
711 assert_eq!(t.format("%r").to_string(), "03:05:07 AM");
712 assert_eq!(t.format("%t%n%%%n%t").to_string(), "\t\n%\n\t");
713
714 let t = NaiveTime::from_hms_micro_opt(3, 5, 7, 432100).unwrap();
715 assert_eq!(t.format("%S,%f,%.f").to_string(), "07,432100000,.432100");
716 assert_eq!(t.format("%.3f,%.6f,%.9f").to_string(), ".432,.432100,.432100000");
717
718 let t = NaiveTime::from_hms_milli_opt(3, 5, 7, 210).unwrap();
719 assert_eq!(t.format("%S,%f,%.f").to_string(), "07,210000000,.210");
720 assert_eq!(t.format("%.3f,%.6f,%.9f").to_string(), ".210,.210000,.210000000");
721
722 let t = NaiveTime::from_hms_opt(3, 5, 7).unwrap();
723 assert_eq!(t.format("%S,%f,%.f").to_string(), "07,000000000,");
724 assert_eq!(t.format("%.3f,%.6f,%.9f").to_string(), ".000,.000000,.000000000");
725
726 // corner cases
727 assert_eq!(
728 NaiveTime::from_hms_opt(13, 57, 9).unwrap().format("%r").to_string(),
729 "01:57:09 PM"
730 );
731 assert_eq!(
732 NaiveTime::from_hms_milli_opt(23, 59, 59, 1_000).unwrap().format("%X").to_string(),
733 "23:59:60"
734 );
735 }
736
737 #[test]
738 #[cfg(feature = "alloc")]
739 fn test_datetime_format() {
740 let dt =
741 NaiveDate::from_ymd_opt(2010, 9, 8).unwrap().and_hms_milli_opt(7, 6, 54, 321).unwrap();
742 assert_eq!(dt.format("%c").to_string(), "Wed Sep 8 07:06:54 2010");
743 assert_eq!(dt.format("%s").to_string(), "1283929614");
744 assert_eq!(dt.format("%t%n%%%n%t").to_string(), "\t\n%\n\t");
745
746 // a horror of leap second: coming near to you.
747 let dt = NaiveDate::from_ymd_opt(2012, 6, 30)
748 .unwrap()
749 .and_hms_milli_opt(23, 59, 59, 1_000)
750 .unwrap();
751 assert_eq!(dt.format("%c").to_string(), "Sat Jun 30 23:59:60 2012");
752 assert_eq!(dt.format("%s").to_string(), "1341100799"); // not 1341100800, it's intentional.
753 }
754
755 #[test]
756 #[cfg(feature = "alloc")]
757 fn test_datetime_format_alignment() {
758 let datetime = Utc
759 .with_ymd_and_hms(2007, 1, 2, 12, 34, 56)
760 .unwrap()
761 .with_nanosecond(123456789)
762 .unwrap();
763
764 // Item::Literal, odd number of padding bytes.
765 let percent = datetime.format("%%");
766 assert_eq!(" %", format!("{:>4}", percent));
767 assert_eq!("% ", format!("{:<4}", percent));
768 assert_eq!(" % ", format!("{:^4}", percent));
769
770 // Item::Numeric, custom non-ASCII padding character
771 let year = datetime.format("%Y");
772 assert_eq!("——2007", format!("{:—>6}", year));
773 assert_eq!("2007——", format!("{:—<6}", year));
774 assert_eq!("—2007—", format!("{:—^6}", year));
775
776 // Item::Fixed
777 let tz = datetime.format("%Z");
778 assert_eq!(" UTC", format!("{:>5}", tz));
779 assert_eq!("UTC ", format!("{:<5}", tz));
780 assert_eq!(" UTC ", format!("{:^5}", tz));
781
782 // [Item::Numeric, Item::Space, Item::Literal, Item::Space, Item::Numeric]
783 let ymd = datetime.format("%Y %B %d");
784 assert_eq!(" 2007 January 02", format!("{:>17}", ymd));
785 assert_eq!("2007 January 02 ", format!("{:<17}", ymd));
786 assert_eq!(" 2007 January 02 ", format!("{:^17}", ymd));
787
788 // Truncated
789 let time = datetime.format("%T%.6f");
790 assert_eq!("12:34:56.1234", format!("{:.13}", time));
791 }
792
793 #[test]
794 fn test_offset_formatting() {
795 fn check_all(precision: OffsetPrecision, expected: [[&str; 7]; 12]) {
796 fn check(
797 precision: OffsetPrecision,
798 colons: Colons,
799 padding: Pad,
800 allow_zulu: bool,
801 offsets: [FixedOffset; 7],
802 expected: [&str; 7],
803 ) {
804 let offset_format = OffsetFormat { precision, colons, allow_zulu, padding };
805 for (offset, expected) in offsets.iter().zip(expected.iter()) {
806 let mut output = String::new();
807 offset_format.format(&mut output, *offset).unwrap();
808 assert_eq!(&output, expected);
809 }
810 }
811 // +03:45, -03:30, +11:00, -11:00:22, +02:34:26, -12:34:30, +00:00
812 let offsets = [
813 FixedOffset::east_opt(13_500).unwrap(),
814 FixedOffset::east_opt(-12_600).unwrap(),
815 FixedOffset::east_opt(39_600).unwrap(),
816 FixedOffset::east_opt(-39_622).unwrap(),
817 FixedOffset::east_opt(9266).unwrap(),
818 FixedOffset::east_opt(-45270).unwrap(),
819 FixedOffset::east_opt(0).unwrap(),
820 ];
821 check(precision, Colons::Colon, Pad::Zero, false, offsets, expected[0]);
822 check(precision, Colons::Colon, Pad::Zero, true, offsets, expected[1]);
823 check(precision, Colons::Colon, Pad::Space, false, offsets, expected[2]);
824 check(precision, Colons::Colon, Pad::Space, true, offsets, expected[3]);
825 check(precision, Colons::Colon, Pad::None, false, offsets, expected[4]);
826 check(precision, Colons::Colon, Pad::None, true, offsets, expected[5]);
827 check(precision, Colons::None, Pad::Zero, false, offsets, expected[6]);
828 check(precision, Colons::None, Pad::Zero, true, offsets, expected[7]);
829 check(precision, Colons::None, Pad::Space, false, offsets, expected[8]);
830 check(precision, Colons::None, Pad::Space, true, offsets, expected[9]);
831 check(precision, Colons::None, Pad::None, false, offsets, expected[10]);
832 check(precision, Colons::None, Pad::None, true, offsets, expected[11]);
833 // `Colons::Maybe` should format the same as `Colons::None`
834 check(precision, Colons::Maybe, Pad::Zero, false, offsets, expected[6]);
835 check(precision, Colons::Maybe, Pad::Zero, true, offsets, expected[7]);
836 check(precision, Colons::Maybe, Pad::Space, false, offsets, expected[8]);
837 check(precision, Colons::Maybe, Pad::Space, true, offsets, expected[9]);
838 check(precision, Colons::Maybe, Pad::None, false, offsets, expected[10]);
839 check(precision, Colons::Maybe, Pad::None, true, offsets, expected[11]);
840 }
841 check_all(
842 OffsetPrecision::Hours,
843 [
844 ["+03", "-03", "+11", "-11", "+02", "-12", "+00"],
845 ["+03", "-03", "+11", "-11", "+02", "-12", "Z"],
846 [" +3", " -3", "+11", "-11", " +2", "-12", " +0"],
847 [" +3", " -3", "+11", "-11", " +2", "-12", "Z"],
848 ["+3", "-3", "+11", "-11", "+2", "-12", "+0"],
849 ["+3", "-3", "+11", "-11", "+2", "-12", "Z"],
850 ["+03", "-03", "+11", "-11", "+02", "-12", "+00"],
851 ["+03", "-03", "+11", "-11", "+02", "-12", "Z"],
852 [" +3", " -3", "+11", "-11", " +2", "-12", " +0"],
853 [" +3", " -3", "+11", "-11", " +2", "-12", "Z"],
854 ["+3", "-3", "+11", "-11", "+2", "-12", "+0"],
855 ["+3", "-3", "+11", "-11", "+2", "-12", "Z"],
856 ],
857 );
858 check_all(
859 OffsetPrecision::Minutes,
860 [
861 ["+03:45", "-03:30", "+11:00", "-11:00", "+02:34", "-12:35", "+00:00"],
862 ["+03:45", "-03:30", "+11:00", "-11:00", "+02:34", "-12:35", "Z"],
863 [" +3:45", " -3:30", "+11:00", "-11:00", " +2:34", "-12:35", " +0:00"],
864 [" +3:45", " -3:30", "+11:00", "-11:00", " +2:34", "-12:35", "Z"],
865 ["+3:45", "-3:30", "+11:00", "-11:00", "+2:34", "-12:35", "+0:00"],
866 ["+3:45", "-3:30", "+11:00", "-11:00", "+2:34", "-12:35", "Z"],
867 ["+0345", "-0330", "+1100", "-1100", "+0234", "-1235", "+0000"],
868 ["+0345", "-0330", "+1100", "-1100", "+0234", "-1235", "Z"],
869 [" +345", " -330", "+1100", "-1100", " +234", "-1235", " +000"],
870 [" +345", " -330", "+1100", "-1100", " +234", "-1235", "Z"],
871 ["+345", "-330", "+1100", "-1100", "+234", "-1235", "+000"],
872 ["+345", "-330", "+1100", "-1100", "+234", "-1235", "Z"],
873 ],
874 );
875 #[rustfmt::skip]
876 check_all(
877 OffsetPrecision::Seconds,
878 [
879 ["+03:45:00", "-03:30:00", "+11:00:00", "-11:00:22", "+02:34:26", "-12:34:30", "+00:00:00"],
880 ["+03:45:00", "-03:30:00", "+11:00:00", "-11:00:22", "+02:34:26", "-12:34:30", "Z"],
881 [" +3:45:00", " -3:30:00", "+11:00:00", "-11:00:22", " +2:34:26", "-12:34:30", " +0:00:00"],
882 [" +3:45:00", " -3:30:00", "+11:00:00", "-11:00:22", " +2:34:26", "-12:34:30", "Z"],
883 ["+3:45:00", "-3:30:00", "+11:00:00", "-11:00:22", "+2:34:26", "-12:34:30", "+0:00:00"],
884 ["+3:45:00", "-3:30:00", "+11:00:00", "-11:00:22", "+2:34:26", "-12:34:30", "Z"],
885 ["+034500", "-033000", "+110000", "-110022", "+023426", "-123430", "+000000"],
886 ["+034500", "-033000", "+110000", "-110022", "+023426", "-123430", "Z"],
887 [" +34500", " -33000", "+110000", "-110022", " +23426", "-123430", " +00000"],
888 [" +34500", " -33000", "+110000", "-110022", " +23426", "-123430", "Z"],
889 ["+34500", "-33000", "+110000", "-110022", "+23426", "-123430", "+00000"],
890 ["+34500", "-33000", "+110000", "-110022", "+23426", "-123430", "Z"],
891 ],
892 );
893 check_all(
894 OffsetPrecision::OptionalMinutes,
895 [
896 ["+03:45", "-03:30", "+11", "-11", "+02:34", "-12:35", "+00"],
897 ["+03:45", "-03:30", "+11", "-11", "+02:34", "-12:35", "Z"],
898 [" +3:45", " -3:30", "+11", "-11", " +2:34", "-12:35", " +0"],
899 [" +3:45", " -3:30", "+11", "-11", " +2:34", "-12:35", "Z"],
900 ["+3:45", "-3:30", "+11", "-11", "+2:34", "-12:35", "+0"],
901 ["+3:45", "-3:30", "+11", "-11", "+2:34", "-12:35", "Z"],
902 ["+0345", "-0330", "+11", "-11", "+0234", "-1235", "+00"],
903 ["+0345", "-0330", "+11", "-11", "+0234", "-1235", "Z"],
904 [" +345", " -330", "+11", "-11", " +234", "-1235", " +0"],
905 [" +345", " -330", "+11", "-11", " +234", "-1235", "Z"],
906 ["+345", "-330", "+11", "-11", "+234", "-1235", "+0"],
907 ["+345", "-330", "+11", "-11", "+234", "-1235", "Z"],
908 ],
909 );
910 check_all(
911 OffsetPrecision::OptionalSeconds,
912 [
913 ["+03:45", "-03:30", "+11:00", "-11:00:22", "+02:34:26", "-12:34:30", "+00:00"],
914 ["+03:45", "-03:30", "+11:00", "-11:00:22", "+02:34:26", "-12:34:30", "Z"],
915 [" +3:45", " -3:30", "+11:00", "-11:00:22", " +2:34:26", "-12:34:30", " +0:00"],
916 [" +3:45", " -3:30", "+11:00", "-11:00:22", " +2:34:26", "-12:34:30", "Z"],
917 ["+3:45", "-3:30", "+11:00", "-11:00:22", "+2:34:26", "-12:34:30", "+0:00"],
918 ["+3:45", "-3:30", "+11:00", "-11:00:22", "+2:34:26", "-12:34:30", "Z"],
919 ["+0345", "-0330", "+1100", "-110022", "+023426", "-123430", "+0000"],
920 ["+0345", "-0330", "+1100", "-110022", "+023426", "-123430", "Z"],
921 [" +345", " -330", "+1100", "-110022", " +23426", "-123430", " +000"],
922 [" +345", " -330", "+1100", "-110022", " +23426", "-123430", "Z"],
923 ["+345", "-330", "+1100", "-110022", "+23426", "-123430", "+000"],
924 ["+345", "-330", "+1100", "-110022", "+23426", "-123430", "Z"],
925 ],
926 );
927 check_all(
928 OffsetPrecision::OptionalMinutesAndSeconds,
929 [
930 ["+03:45", "-03:30", "+11", "-11:00:22", "+02:34:26", "-12:34:30", "+00"],
931 ["+03:45", "-03:30", "+11", "-11:00:22", "+02:34:26", "-12:34:30", "Z"],
932 [" +3:45", " -3:30", "+11", "-11:00:22", " +2:34:26", "-12:34:30", " +0"],
933 [" +3:45", " -3:30", "+11", "-11:00:22", " +2:34:26", "-12:34:30", "Z"],
934 ["+3:45", "-3:30", "+11", "-11:00:22", "+2:34:26", "-12:34:30", "+0"],
935 ["+3:45", "-3:30", "+11", "-11:00:22", "+2:34:26", "-12:34:30", "Z"],
936 ["+0345", "-0330", "+11", "-110022", "+023426", "-123430", "+00"],
937 ["+0345", "-0330", "+11", "-110022", "+023426", "-123430", "Z"],
938 [" +345", " -330", "+11", "-110022", " +23426", "-123430", " +0"],
939 [" +345", " -330", "+11", "-110022", " +23426", "-123430", "Z"],
940 ["+345", "-330", "+11", "-110022", "+23426", "-123430", "+0"],
941 ["+345", "-330", "+11", "-110022", "+23426", "-123430", "Z"],
942 ],
943 );
944 }
945}
946