Function format_range

src/repr/src/strconv.rs:1534–1579

Writes a [`Range`] to `buf`.

(
    buf: &mut F,
    r: &Range<V>,
    mut format_elem: impl FnMut(RangeElementWriter<F>, Option<&V>) -> Result<Nestable, E>,
)

/// Writes a [`Range`] to `buf`.
pub fn format_range<F, V, E>(
    buf: &mut F,
    r: &Range<V>,
    mut format_elem: impl FnMut(RangeElementWriter<F>, Option<&V>) -> Result<Nestable, E>,
) -> Result<Nestable, E>
where
    F: FormatBuffer,
{
    let range = match &r.inner {
        None => {
            buf.write_str("empty");
            return Ok(Nestable::MayNeedEscaping);
        }
        Some(i) => i,
    };

    if range.lower.inclusive {
        buf.write_char('[');
    } else {
        buf.write_char('(');
    }

    let start = buf.len();
    if let Nestable::MayNeedEscaping =
        format_elem(RangeElementWriter(buf), range.lower.bound.as_ref())?
    {
        escape_elem::<_, ListElementEscaper>(buf, start);
    }

    buf.write_char(',');

    let start = buf.len();
    if let Nestable::MayNeedEscaping =
        format_elem(RangeElementWriter(buf), range.upper.bound.as_ref())?
    {
        escape_elem::<_, ListElementEscaper>(buf, start);
    }

    if range.upper.inclusive {
        buf.write_char(']');
    } else {
        buf.write_char(')');
    }

    Ok(Nestable::MayNeedEscaping)
}

/// A helper for `format_range` that formats a single record element.
#[derive(Debug)]