use std::sync::LazyLock; use chrono::format::StrftimeItems;use jj_lib::backend::Timestamp;use jj_lib::backend::TimestampOutOfRange; /// Parsed formatting items which should never contain an error.#[derive(Clone, Debug, Eq, PartialEq)]pub struct FormattingItems<'a> {    items: Vec<chrono::format::Item<'a>>,} impl<'a> FormattingItems<'a> {    /// Parses strftime-like format string.    pub fn parse(format: &'a str) -> Option<Self> {        // If the parsed format contained an error, format().to_string() would panic.        let items = StrftimeItems::new(format)            .map(|item| match item {                chrono::format::Item::Error => None,                _ => Some(item),            })            .collect::<Option<_>>()?;        Some(FormattingItems { items })    }     pub fn into_owned(self) -> FormattingItems<'static> {        use chrono::format::Item;        let items = self            .items            .into_iter()            .map(|item| match item {                Item::Literal(s) => Item::OwnedLiteral(s.into()),                Item::OwnedLiteral(s) => Item::OwnedLiteral(s),                Item::Space(s) => Item::OwnedSpace(s.into()),                Item::OwnedSpace(s) => Item::OwnedSpace(s),                Item::Numeric(spec, pad) => Item::Numeric(spec, pad),                Item::Fixed(spec) => Item::Fixed(spec),                Item::Error => Item::Error, // shouldn't exist, but just copy            })            .collect();        FormattingItems { items }    }} pub fn format_absolute_timestamp(timestamp: &Timestamp) -> Result<String, TimestampOutOfRange> {    static DEFAULT_FORMAT: LazyLock<FormattingItems> =        LazyLock::new(|| FormattingItems::parse("%Y-%m-%d %H:%M:%S.%3f %:z").unwrap());    format_absolute_timestamp_with(timestamp, &DEFAULT_FORMAT)} pub fn format_absolute_timestamp_with(    timestamp: &Timestamp,    format: &FormattingItems,) -> Result<String, TimestampOutOfRange> {    let datetime = timestamp.to_datetime()?;    Ok(datetime.format_with_items(format.items.iter()).to_string())} pub fn format_duration(    from: &Timestamp,    to: &Timestamp,    format: &timeago::Formatter,) -> Result<String, TimestampOutOfRange> {    let duration = to        .to_datetime()?        .signed_duration_since(from.to_datetime()?)        .to_std()        .map_err(|_: chrono::OutOfRangeError| TimestampOutOfRange)?;    Ok(format.convert(duration))}