Struct chrono::format::strftime::StrftimeItems
source · pub struct StrftimeItems<'a> { /* private fields */ }
Expand description
Parsing iterator for strftime
-like format strings.
See the format::strftime
module for supported formatting
specifiers.
StrftimeItems
is used in combination with more low-level methods such as format::parse()
or format_with_items
.
If formatting or parsing date and time values is not performance-critical, the methods
parse_from_str
and format
on types such as DateTime
are easier to
use.
Implementations§
source§impl<'a> StrftimeItems<'a>
impl<'a> StrftimeItems<'a>
sourcepub const fn new(s: &'a str) -> StrftimeItems<'a> ⓘ
pub const fn new(s: &'a str) -> StrftimeItems<'a> ⓘ
Creates a new parsing iterator from a strftime
-like format string.
§Errors
While iterating Item::Error
will be returned if the format string contains an invalid
or unrecognized formatting specifier.
§Example
use chrono::format::*;
let strftime_parser = StrftimeItems::new("%F"); // %F: year-month-day (ISO 8601)
const ISO8601_YMD_ITEMS: &[Item<'static>] = &[
Item::Numeric(Numeric::Year, Pad::Zero),
Item::Literal("-"),
Item::Numeric(Numeric::Month, Pad::Zero),
Item::Literal("-"),
Item::Numeric(Numeric::Day, Pad::Zero),
];
assert!(strftime_parser.eq(ISO8601_YMD_ITEMS.iter().cloned()));
sourcepub fn parse(self) -> Result<Vec<Item<'a>>, ParseError>
pub fn parse(self) -> Result<Vec<Item<'a>>, ParseError>
Parse format string into a Vec
of formatting Item
’s.
If you need to format or parse multiple values with the same format string, it is more
efficient to convert it to a Vec
of formatting Item
’s than to re-parse the format
string on every use.
The format_with_items
methods on DateTime
, NaiveDateTime
, NaiveDate
and
NaiveTime
accept the result for formatting. format::parse()
can make use of it for
parsing.
§Errors
Returns an error if the format string contains an invalid or unrecognized formatting specifier.
§Example
use chrono::format::{parse, Parsed, StrftimeItems};
use chrono::NaiveDate;
let fmt_items = StrftimeItems::new("%e %b %Y %k.%M").parse()?;
let datetime = NaiveDate::from_ymd_opt(2023, 7, 11).unwrap().and_hms_opt(9, 0, 0).unwrap();
// Formatting
assert_eq!(
datetime.format_with_items(fmt_items.as_slice().iter()).to_string(),
"11 Jul 2023 9.00"
);
// Parsing
let mut parsed = Parsed::new();
parse(&mut parsed, "11 Jul 2023 9.00", fmt_items.as_slice().iter())?;
let parsed_dt = parsed.to_naive_datetime_with_offset(0)?;
assert_eq!(parsed_dt, datetime);
sourcepub fn parse_to_owned(self) -> Result<Vec<Item<'static>>, ParseError>
pub fn parse_to_owned(self) -> Result<Vec<Item<'static>>, ParseError>
Parse format string into a Vec
of Item
’s that contain no references to slices of the
format string.
A Vec
created with StrftimeItems::parse
contains references to the format string,
binding the lifetime of the Vec
to that string. StrftimeItems::parse_to_owned
will
convert the references to owned types.
§Errors
Returns an error if the format string contains an invalid or unrecognized formatting specifier.
§Example
use chrono::format::{Item, ParseError, StrftimeItems};
use chrono::NaiveDate;
fn format_items(date_fmt: &str, time_fmt: &str) -> Result<Vec<Item<'static>>, ParseError> {
// `fmt_string` is dropped at the end of this function.
let fmt_string = format!("{} {}", date_fmt, time_fmt);
StrftimeItems::new(&fmt_string).parse_to_owned()
}
let fmt_items = format_items("%e %b %Y", "%k.%M")?;
let datetime = NaiveDate::from_ymd_opt(2023, 7, 11).unwrap().and_hms_opt(9, 0, 0).unwrap();
assert_eq!(
datetime.format_with_items(fmt_items.as_slice().iter()).to_string(),
"11 Jul 2023 9.00"
);
Trait Implementations§
source§impl<'a> Clone for StrftimeItems<'a>
impl<'a> Clone for StrftimeItems<'a>
source§impl<'a> Debug for StrftimeItems<'a>
impl<'a> Debug for StrftimeItems<'a>
source§impl<'a> Iterator for StrftimeItems<'a>
impl<'a> Iterator for StrftimeItems<'a>
source§fn next(&mut self) -> Option<Item<'a>>
fn next(&mut self) -> Option<Item<'a>>
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impl<'a> Freeze for StrftimeItems<'a>
impl<'a> RefUnwindSafe for StrftimeItems<'a>
impl<'a> Send for StrftimeItems<'a>
impl<'a> Sync for StrftimeItems<'a>
impl<'a> Unpin for StrftimeItems<'a>
impl<'a> UnwindSafe for StrftimeItems<'a>
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source§impl<T> BorrowMut<T> for Twhere
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impl<T> BorrowMut<T> for Twhere
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fn borrow_mut(&mut self) -> &mut T
source§impl<T> CloneToUninit for Twhere
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source§default unsafe fn clone_to_uninit(&self, dst: *mut T)
default unsafe fn clone_to_uninit(&self, dst: *mut T)
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