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</pre><pre class="rust"><code><span class="comment">// This is a part of Chrono.
// See README.md and LICENSE.txt for details.
</span><span class="doccomment">//! ISO 8601 week.
</span><span class="kw">use </span>core::fmt;
<span class="kw">use </span><span class="kw">super</span>::internals::{DateImpl, Of, YearFlags};
<span class="attr">#[cfg(feature = <span class="string">"rkyv"</span>)]
</span><span class="kw">use </span>rkyv::{Archive, Deserialize, Serialize};
<span class="doccomment">/// ISO 8601 week.
///
/// This type, combined with [`Weekday`](../enum.Weekday.html),
/// constitutes the ISO 8601 [week date](./struct.NaiveDate.html#week-date).
/// One can retrieve this type from the existing [`Datelike`](../trait.Datelike.html) types
/// via the [`Datelike::iso_week`](../trait.Datelike.html#tymethod.iso_week) method.
</span><span class="attr">#[derive(PartialEq, Eq, PartialOrd, Ord, Copy, Clone, Hash)]
#[cfg_attr(feature = <span class="string">"rkyv"</span>, derive(Archive, Deserialize, Serialize))]
</span><span class="kw">pub struct </span>IsoWeek {
<span class="comment">// note that this allows for larger year range than `NaiveDate`.
// this is crucial because we have an edge case for the first and last week supported,
// which year number might not match the calendar year number.
</span>ywf: DateImpl, <span class="comment">// (year << 10) | (week << 4) | flag
</span>}
<span class="doccomment">/// Returns the corresponding `IsoWeek` from the year and the `Of` internal value.
</span><span class="comment">//
// internal use only. we don't expose the public constructor for `IsoWeek` for now,
// because the year range for the week date and the calendar date do not match and
// it is confusing to have a date that is out of range in one and not in another.
// currently we sidestep this issue by making `IsoWeek` fully dependent of `Datelike`.
</span><span class="kw">pub</span>(<span class="kw">super</span>) <span class="kw">fn </span>iso_week_from_yof(year: i32, of: Of) -> IsoWeek {
<span class="kw">let </span>(rawweek, <span class="kw">_</span>) = of.isoweekdate_raw();
<span class="kw">let </span>(year, week) = <span class="kw">if </span>rawweek < <span class="number">1 </span>{
<span class="comment">// previous year
</span><span class="kw">let </span>prevlastweek = YearFlags::from_year(year - <span class="number">1</span>).nisoweeks();
(year - <span class="number">1</span>, prevlastweek)
} <span class="kw">else </span>{
<span class="kw">let </span>lastweek = of.flags().nisoweeks();
<span class="kw">if </span>rawweek > lastweek {
<span class="comment">// next year
</span>(year + <span class="number">1</span>, <span class="number">1</span>)
} <span class="kw">else </span>{
(year, rawweek)
}
};
<span class="kw">let </span>flags = YearFlags::from_year(year);
IsoWeek { ywf: (year << <span class="number">10</span>) | (week << <span class="number">4</span>) <span class="kw">as </span>DateImpl | DateImpl::from(flags.<span class="number">0</span>) }
}
<span class="kw">impl </span>IsoWeek {
<span class="doccomment">/// Returns the year number for this ISO week.
///
/// # Example
///
/// ```
/// use chrono::{NaiveDate, Datelike, Weekday};
///
/// let d = NaiveDate::from_isoywd_opt(2015, 1, Weekday::Mon).unwrap();
/// assert_eq!(d.iso_week().year(), 2015);
/// ```
///
/// This year number might not match the calendar year number.
/// Continuing the example...
///
/// ```
/// # use chrono::{NaiveDate, Datelike, Weekday};
/// # let d = NaiveDate::from_isoywd_opt(2015, 1, Weekday::Mon).unwrap();
/// assert_eq!(d.year(), 2014);
/// assert_eq!(d, NaiveDate::from_ymd_opt(2014, 12, 29).unwrap());
/// ```
</span><span class="attr">#[inline]
</span><span class="kw">pub const fn </span>year(<span class="kw-2">&</span><span class="self">self</span>) -> i32 {
<span class="self">self</span>.ywf >> <span class="number">10
</span>}
<span class="doccomment">/// Returns the ISO week number starting from 1.
///
/// The return value ranges from 1 to 53. (The last week of year differs by years.)
///
/// # Example
///
/// ```
/// use chrono::{NaiveDate, Datelike, Weekday};
///
/// let d = NaiveDate::from_isoywd_opt(2015, 15, Weekday::Mon).unwrap();
/// assert_eq!(d.iso_week().week(), 15);
/// ```
</span><span class="attr">#[inline]
</span><span class="kw">pub const fn </span>week(<span class="kw-2">&</span><span class="self">self</span>) -> u32 {
((<span class="self">self</span>.ywf >> <span class="number">4</span>) & <span class="number">0x3f</span>) <span class="kw">as </span>u32
}
<span class="doccomment">/// Returns the ISO week number starting from 0.
///
/// The return value ranges from 0 to 52. (The last week of year differs by years.)
///
/// # Example
///
/// ```
/// use chrono::{NaiveDate, Datelike, Weekday};
///
/// let d = NaiveDate::from_isoywd_opt(2015, 15, Weekday::Mon).unwrap();
/// assert_eq!(d.iso_week().week0(), 14);
/// ```
</span><span class="attr">#[inline]
</span><span class="kw">pub const fn </span>week0(<span class="kw-2">&</span><span class="self">self</span>) -> u32 {
((<span class="self">self</span>.ywf >> <span class="number">4</span>) & <span class="number">0x3f</span>) <span class="kw">as </span>u32 - <span class="number">1
</span>}
}
<span class="doccomment">/// The `Debug` output of the ISO week `w` is the same as
/// [`d.format("%G-W%V")`](../format/strftime/index.html)
/// where `d` is any `NaiveDate` value in that week.
///
/// # Example
///
/// ```
/// use chrono::{NaiveDate, Datelike};
///
/// assert_eq!(format!("{:?}", NaiveDate::from_ymd_opt(2015, 9, 5).unwrap().iso_week()), "2015-W36");
/// assert_eq!(format!("{:?}", NaiveDate::from_ymd_opt( 0, 1, 3).unwrap().iso_week()), "0000-W01");
/// assert_eq!(format!("{:?}", NaiveDate::from_ymd_opt(9999, 12, 31).unwrap().iso_week()), "9999-W52");
/// ```
///
/// ISO 8601 requires an explicit sign for years before 1 BCE or after 9999 CE.
///
/// ```
/// # use chrono::{NaiveDate, Datelike};
/// assert_eq!(format!("{:?}", NaiveDate::from_ymd_opt( 0, 1, 2).unwrap().iso_week()), "-0001-W52");
/// assert_eq!(format!("{:?}", NaiveDate::from_ymd_opt(10000, 12, 31).unwrap().iso_week()), "+10000-W52");
/// ```
</span><span class="kw">impl </span>fmt::Debug <span class="kw">for </span>IsoWeek {
<span class="kw">fn </span>fmt(<span class="kw-2">&</span><span class="self">self</span>, f: <span class="kw-2">&mut </span>fmt::Formatter) -> fmt::Result {
<span class="kw">let </span>year = <span class="self">self</span>.year();
<span class="kw">let </span>week = <span class="self">self</span>.week();
<span class="kw">if </span>(<span class="number">0</span>..=<span class="number">9999</span>).contains(<span class="kw-2">&</span>year) {
<span class="macro">write!</span>(f, <span class="string">"{:04}-W{:02}"</span>, year, week)
} <span class="kw">else </span>{
<span class="comment">// ISO 8601 requires the explicit sign for out-of-range years
</span><span class="macro">write!</span>(f, <span class="string">"{:+05}-W{:02}"</span>, year, week)
}
}
}
<span class="attr">#[cfg(test)]
</span><span class="kw">mod </span>tests {
<span class="kw">use </span><span class="kw">crate</span>::naive::{internals, NaiveDate};
<span class="kw">use </span><span class="kw">crate</span>::Datelike;
<span class="attr">#[test]
</span><span class="kw">fn </span>test_iso_week_extremes() {
<span class="kw">let </span>minweek = NaiveDate::MIN.iso_week();
<span class="kw">let </span>maxweek = NaiveDate::MAX.iso_week();
<span class="macro">assert_eq!</span>(minweek.year(), internals::MIN_YEAR);
<span class="macro">assert_eq!</span>(minweek.week(), <span class="number">1</span>);
<span class="macro">assert_eq!</span>(minweek.week0(), <span class="number">0</span>);
<span class="attr">#[cfg(any(feature = <span class="string">"alloc"</span>, feature = <span class="string">"std"</span>))]
</span><span class="macro">assert_eq!</span>(<span class="macro">format!</span>(<span class="string">"{:?}"</span>, minweek), NaiveDate::MIN.format(<span class="string">"%G-W%V"</span>).to_string());
<span class="macro">assert_eq!</span>(maxweek.year(), internals::MAX_YEAR + <span class="number">1</span>);
<span class="macro">assert_eq!</span>(maxweek.week(), <span class="number">1</span>);
<span class="macro">assert_eq!</span>(maxweek.week0(), <span class="number">0</span>);
<span class="attr">#[cfg(any(feature = <span class="string">"alloc"</span>, feature = <span class="string">"std"</span>))]
</span><span class="macro">assert_eq!</span>(<span class="macro">format!</span>(<span class="string">"{:?}"</span>, maxweek), NaiveDate::MAX.format(<span class="string">"%G-W%V"</span>).to_string());
}
<span class="attr">#[test]
</span><span class="kw">fn </span>test_iso_week_equivalence_for_first_week() {
<span class="kw">let </span>monday = NaiveDate::from_ymd_opt(<span class="number">2024</span>, <span class="number">12</span>, <span class="number">30</span>).unwrap();
<span class="kw">let </span>friday = NaiveDate::from_ymd_opt(<span class="number">2025</span>, <span class="number">1</span>, <span class="number">3</span>).unwrap();
<span class="macro">assert_eq!</span>(monday.iso_week(), friday.iso_week());
}
<span class="attr">#[test]
</span><span class="kw">fn </span>test_iso_week_equivalence_for_last_week() {
<span class="kw">let </span>monday = NaiveDate::from_ymd_opt(<span class="number">2026</span>, <span class="number">12</span>, <span class="number">28</span>).unwrap();
<span class="kw">let </span>friday = NaiveDate::from_ymd_opt(<span class="number">2027</span>, <span class="number">1</span>, <span class="number">1</span>).unwrap();
<span class="macro">assert_eq!</span>(monday.iso_week(), friday.iso_week());
}
<span class="attr">#[test]
</span><span class="kw">fn </span>test_iso_week_ordering_for_first_week() {
<span class="kw">let </span>monday = NaiveDate::from_ymd_opt(<span class="number">2024</span>, <span class="number">12</span>, <span class="number">30</span>).unwrap();
<span class="kw">let </span>friday = NaiveDate::from_ymd_opt(<span class="number">2025</span>, <span class="number">1</span>, <span class="number">3</span>).unwrap();
<span class="macro">assert!</span>(monday.iso_week() >= friday.iso_week());
<span class="macro">assert!</span>(monday.iso_week() <= friday.iso_week());
}
<span class="attr">#[test]
</span><span class="kw">fn </span>test_iso_week_ordering_for_last_week() {
<span class="kw">let </span>monday = NaiveDate::from_ymd_opt(<span class="number">2026</span>, <span class="number">12</span>, <span class="number">28</span>).unwrap();
<span class="kw">let </span>friday = NaiveDate::from_ymd_opt(<span class="number">2027</span>, <span class="number">1</span>, <span class="number">1</span>).unwrap();
<span class="macro">assert!</span>(monday.iso_week() >= friday.iso_week());
<span class="macro">assert!</span>(monday.iso_week() <= friday.iso_week());
}
}
</code></pre></div>
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