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Remove Mdf::to_of
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pitdicker committed Sep 27, 2023
1 parent be31ddf commit 332c19a
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Showing 2 changed files with 20 additions and 125 deletions.
17 changes: 12 additions & 5 deletions src/naive/date.rs
Original file line number Diff line number Diff line change
Expand Up @@ -257,11 +257,8 @@ impl NaiveDate {
/// Makes a new `NaiveDate` from year and packed month-day-flags.
/// Does not check whether the flags are correct for the provided year.
const fn from_mdf(year: i32, mdf: Mdf) -> Option<NaiveDate> {
if year < MIN_YEAR || year > MAX_YEAR {
return None; // Out-of-range
}
match mdf.to_of() {
Some(of) => Some(NaiveDate { yof: (year << 13) | (of.inner() as i32) }),
match mdf.ordinal() {
Some(ordinal) => NaiveDate::from_ordinal_and_flags(year, ordinal, mdf.year_flags()),
None => None, // Non-existing date
}
}
Expand Down Expand Up @@ -3402,6 +3399,16 @@ mod tests {
}
}

#[test]
fn test_date_to_mdf_to_date() {
for (year, year_flags, _) in YEAR_FLAGS {
for ordinal in 1..=year_flags.ndays() {
let date = NaiveDate::from_yo_opt(year, ordinal).unwrap();
assert_eq!(date, NaiveDate::from_mdf(date.year(), date.mdf()).unwrap());
}
}
}

// Used for testing some methods with all combinations of `YearFlags`.
// (year, flags, first weekday of year)
const YEAR_FLAGS: [(i32, YearFlags, Weekday); 14] = [
Expand Down
128 changes: 8 additions & 120 deletions src/naive/internals.rs
Original file line number Diff line number Diff line change
Expand Up @@ -166,7 +166,6 @@ impl fmt::Debug for YearFlags {
}

// OL: (ordinal << 1) | leap year flag
pub(super) const MIN_OL: u32 = 1 << 1;
pub(super) const MAX_OL: u32 = 366 << 1; // `(366 << 1) | 1` would be day 366 in a non-leap year
pub(super) const MAX_MDL: u32 = (12 << 6) | (31 << 1) | 1;

Expand Down Expand Up @@ -255,70 +254,8 @@ const OL_TO_MDL: &[u8; MAX_OL as usize + 1] = &[
98, // 12
];

/// Ordinal (day of year) and year flags: `(ordinal << 4) | flags`.
///
/// The whole bits except for the least 3 bits are referred as `Ol` (ordinal and leap flag),
/// which is an index to the `OL_TO_MDL` lookup table.
///
/// The methods implemented on `Of` always return a valid value.
#[derive(PartialEq, PartialOrd, Copy, Clone)]
pub(super) struct Of(u32);

impl Of {
#[inline]
pub(super) const fn from_mdf(Mdf(mdf): Mdf) -> Option<Of> {
let mdl = mdf >> 3;
if mdl > MAX_MDL {
// Panicking on out-of-bounds indexing would be reasonable, but just return `None`.
return None;
}
// Array is indexed from `[1..=MAX_MDL]`, with a `0` index having a meaningless value.
let v = MDL_TO_OL[mdl as usize];
let of = Of(mdf.wrapping_sub((v as i32 as u32 & 0x3ff) << 3));
of.validate()
}

#[inline]
pub(super) const fn inner(&self) -> u32 {
self.0
}

/// Returns `(ordinal << 1) | leap-year-flag`.
#[inline]
const fn ol(&self) -> u32 {
self.0 >> 3
}

#[inline]
const fn validate(self) -> Option<Of> {
let ol = self.ol();
match ol >= MIN_OL && ol <= MAX_OL {
true => Some(self),
false => None,
}
}

#[cfg_attr(feature = "cargo-clippy", allow(clippy::wrong_self_convention))]
#[inline]
pub(super) const fn to_mdf(&self) -> Mdf {
Mdf::from_ol(self.0 as i32 >> 3, YearFlags((self.0 & 0b1111) as u8))
}
}

impl fmt::Debug for Of {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
let Of(of) = *self;
write!(
f,
"Of(({} << 4) | {:#04o} /*{:?}*/)",
of >> 4,
of & 0b1111,
YearFlags((of & 0b1111) as u8)
)
}
}

/// Month, day of month and year flags: `(month << 9) | (day << 4) | flags`
/// `M_MMMD_DDDD_LFFF`
///
/// The whole bits except for the least 3 bits are referred as `Mdl`
/// (month, day of month and leap flag),
Expand Down Expand Up @@ -397,12 +334,6 @@ impl Mdf {
Mdf((mdf & !0b1111) | flags as u32)
}

#[cfg_attr(feature = "cargo-clippy", allow(clippy::wrong_self_convention))]
#[inline]
pub(super) const fn to_of(&self) -> Option<Of> {
Of::from_mdf(*self)
}

#[inline]
pub(super) const fn ordinal(&self) -> Option<u32> {
let mdl = self.0 >> 3;
Expand Down Expand Up @@ -434,7 +365,7 @@ impl fmt::Debug for Mdf {

#[cfg(test)]
mod tests {
use super::{Mdf, Of};
use super::Mdf;
use super::{YearFlags, A, AG, B, BA, C, CB, D, DC, E, ED, F, FE, G, GF};

const NONLEAP_FLAGS: [YearFlags; 7] = [A, B, C, D, E, F, G];
Expand Down Expand Up @@ -636,56 +567,13 @@ mod tests {
}
}

#[test]
fn test_of_to_mdf() {
for i in 0u32..=8192 {
if let Some(of) = Of(i).validate() {
assert!(of.to_mdf().valid());
}
}
}

#[test]
fn test_mdf_to_of() {
for i in 0u32..=8192 {
let mdf = Mdf(i);
assert_eq!(mdf.valid(), mdf.to_of().is_some());
}
}

#[test]
fn test_of_to_mdf_to_of() {
for i in 0u32..=8192 {
if let Some(of) = Of(i).validate() {
assert_eq!(of, of.to_mdf().to_of().unwrap());
}
}
}

#[test]
fn test_mdf_to_of_to_mdf() {
for i in 0u32..=8192 {
let mdf = Mdf(i);
if mdf.valid() {
assert_eq!(mdf, mdf.to_of().unwrap().to_mdf());
}
}
}

#[test]
fn test_invalid_returns_none() {
let regular_year = YearFlags::from_year(2023);
let leap_year = YearFlags::from_year(2024);
assert!(Mdf::new(0, 1, regular_year).is_none());
assert!(Mdf::new(13, 1, regular_year).is_none());
assert!(Mdf::new(1, 0, regular_year).is_none());
assert!(Mdf::new(1, 32, regular_year).is_none());
assert!(Mdf::new(2, 31, regular_year).is_some());

assert!(Of::from_mdf(Mdf::new(2, 30, regular_year).unwrap()).is_none());
assert!(Of::from_mdf(Mdf::new(2, 30, leap_year).unwrap()).is_none());
assert!(Of::from_mdf(Mdf::new(2, 29, regular_year).unwrap()).is_none());
assert!(Of::from_mdf(Mdf::new(2, 29, leap_year).unwrap()).is_some());
assert!(Of::from_mdf(Mdf::new(2, 28, regular_year).unwrap()).is_some());
let flags = YearFlags::from_year(2023);
assert!(Mdf::new(0, 1, flags).is_none());
assert!(Mdf::new(13, 1, flags).is_none());
assert!(Mdf::new(1, 0, flags).is_none());
assert!(Mdf::new(1, 32, flags).is_none());
assert!(Mdf::new(2, 31, flags).is_some());
}
}

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