Struct icu_datetime::FixedCalendarDateTimeFormatter

pub struct FixedCalendarDateTimeFormatter<C: CldrCalendar, FSet: DateTimeNamesMarker> { /* private fields */ }

FixedCalendarDateTimeFormatter is a formatter capable of formatting dates and/or times from a calendar selected at compile time.

For more details, please read the crate root docs.

📏 This item has a stack size of 344 bytes on the stable toolchain at release date.

Implementations

impl<C: CldrCalendar, FSet> FixedCalendarDateTimeFormatter<C, FSet>

where FSet::D: TypedDateDataMarkers<C>, FSet::T: TimeMarkers, FSet::Z: ZoneMarkers, FSet: GetField<CompositeFieldSet> + DateTimeMarkers,

pub fn try_new( prefs: DateTimeFormatterPreferences, field_set: FSet, ) -> Result<Self, DateTimeFormatterLoadError>

where Baked: AllFixedCalendarFormattingDataMarkers<C, FSet>,

Creates a new FixedCalendarDateTimeFormatter from compiled data with datetime components specified at build time.

Use this constructor for optimal data size and memory use if you know the required datetime components at build time. If you do not know the datetime components until runtime, use a with_components constructor.

Examples

Basic usage:

use icu::calendar::Date;
use icu::calendar::Gregorian;
use icu::datetime::fieldsets::YMD;
use icu::datetime::FixedCalendarDateTimeFormatter;
use icu::locale::locale;
use writeable::assert_writeable_eq;

let formatter = FixedCalendarDateTimeFormatter::try_new(
    locale!("es-MX").into(),
    YMD::long(),
)
.unwrap();

assert_writeable_eq!(
    formatter.format(&Date::try_new_gregorian(2023, 12, 20).unwrap()),
    "20 de diciembre de 2023"
);

pub fn try_new_with_any_provider<P>( provider: &P, prefs: DateTimeFormatterPreferences, field_set: FSet, ) -> Result<Self, DateTimeFormatterLoadError>

where P: AnyProvider + ?Sized,

A version of [Self :: try_new] that uses custom data provided by an AnyProvider.

📚 Help choosing a constructor

pub fn try_new_with_buffer_provider<P>( provider: &P, prefs: DateTimeFormatterPreferences, field_set: FSet, ) -> Result<Self, DateTimeFormatterLoadError>

where P: BufferProvider + ?Sized,

A version of [Self :: try_new] that uses custom data provided by a BufferProvider.

✨ Enabled with the serde feature.

📚 Help choosing a constructor

pub fn try_new_unstable<P>( provider: &P, prefs: DateTimeFormatterPreferences, field_set: FSet, ) -> Result<Self, DateTimeFormatterLoadError>

where P: ?Sized + AllFixedCalendarFormattingDataMarkers<C, FSet> + AllFixedCalendarExternalDataMarkers,

A version of Self::try_new that uses custom data provided by a DataProvider.

📚 Help choosing a constructor

⚠️ The bounds on provider may change over time, including in SemVer minor releases.

impl<C: CldrCalendar, FSet: DateTimeMarkers> FixedCalendarDateTimeFormatter<C, FSet>

where FSet::D: DateInputMarkers, FSet::T: TimeMarkers, FSet::Z: ZoneMarkers,

pub fn format<I>(&self, input: &I) -> FormattedDateTime<'_>

where I: ?Sized + InFixedCalendar<C> + AllInputMarkers<FSet>,

Formats a datetime. Calendars and fields must match at compile time.

Examples

Mismatched calendars will not compile:

use icu::calendar::Date;
use icu::calendar::cal::Buddhist;
use icu::datetime::FixedCalendarDateTimeFormatter;
use icu::datetime::fieldsets::YMD;
use icu::locale::locale;

let formatter =
    FixedCalendarDateTimeFormatter::<Buddhist, _>::try_new(
        locale!("es-MX").into(),
        YMD::long(),
    )
    .unwrap();

// type mismatch resolving `<Gregorian as AsCalendar>::Calendar == Buddhist`
formatter.format(&Date::try_new_gregorian(2023, 12, 20).unwrap());

A time cannot be passed into the formatter when a date is expected:

use icu::calendar::Time;
use icu::calendar::Gregorian;
use icu::datetime::FixedCalendarDateTimeFormatter;
use icu::datetime::fieldsets::YMD;
use icu::locale::locale;

let formatter =
    FixedCalendarDateTimeFormatter::<Gregorian, _>::try_new(
        locale!("es-MX").into(),
        YMD::long(),
    )
    .unwrap();

// the trait `GetField<AnyCalendarKind>`
// is not implemented for `icu::icu_calendar::Time`
formatter.format(&Time::try_new(0, 0, 0, 0).unwrap());

impl<C: CldrCalendar, FSet: DateTimeMarkers> FixedCalendarDateTimeFormatter<C, FSet>

pub fn into_formatter(self, calendar: C) -> DateTimeFormatter<FSet>

where C: IntoAnyCalendar,

Make this FixedCalendarDateTimeFormatter adopt a calendar so it can format any date.

This is useful if you need a DateTimeFormatter but know the calendar system ahead of time, so that you do not need to link extra data you aren’t using.

Examples

use icu::calendar::cal::Hebrew;
use icu::calendar::Date;
use icu::datetime::fieldsets::YMD;
use icu::datetime::FixedCalendarDateTimeFormatter;
use icu::locale::locale;
use writeable::assert_writeable_eq;

let formatter = FixedCalendarDateTimeFormatter::try_new(
    locale!("en").into(),
    YMD::long(),
)
.unwrap()
.into_formatter(Hebrew::new());

let date = Date::try_new_iso(2024, 10, 14).unwrap();

assert_writeable_eq!(
    formatter.format_any_calendar(&date),
    "12 Tishri 5785"
);

pub fn with_fset<FSet2: DateTimeNamesFrom<FSet>>( self, ) -> FixedCalendarDateTimeFormatter<C, FSet2>

Maps a FixedCalendarDateTimeFormatter of a specific FSet to a more general FSet.

For example, this can transform a formatter for YMD to one for DateFieldSet.

Examples

use icu::calendar::Gregorian;
use icu::calendar::DateTime;
use icu::datetime::FixedCalendarDateTimeFormatter;
use icu::datetime::fieldsets::{YMD, enums::DateFieldSet};
use icu::locale::locale;
use writeable::assert_writeable_eq;

let specific_formatter = FixedCalendarDateTimeFormatter::try_new(
    locale!("fr").into(),
    YMD::medium(),
)
.unwrap();

// Test that the specific formatter works:
let datetime = DateTime::try_new_gregorian(2024, 12, 20, 14, 30, 0).unwrap();
assert_writeable_eq!(
    specific_formatter.format(&datetime),
    "20 déc. 2024"
);

// Make a more general formatter:
let general_formatter = specific_formatter.with_fset::<DateFieldSet>();

// Test that it still works:
assert_writeable_eq!(
    general_formatter.format(&datetime),
    "20 déc. 2024"
);

Trait Implementations

impl<C: Debug + CldrCalendar, FSet: Debug + DateTimeNamesMarker> Debug for FixedCalendarDateTimeFormatter<C, FSet>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.