Trait TreeMetrics

pub trait TreeMetrics<E: ContentTraits>
where
    Self: Debug + Copy + Clone + PartialEq + Eq,
{
    type Update: Debug + Default + PartialEq + Eq;
    type Value: Copy + Clone + Default + Debug + AddAssign + SubAssign + PartialEq + Eq + Sized;

    const CAN_COUNT_ITEMS: bool = false;

    // Required methods
    fn increment_marker(marker: &mut Self::Update, entry: &E);
    fn decrement_marker(marker: &mut Self::Update, entry: &E);
    fn decrement_marker_by_val(marker: &mut Self::Update, val: &Self::Value);
    fn update_offset_by_marker(offset: &mut Self::Value, by: &Self::Update);
    fn increment_offset(offset: &mut Self::Value, by: &E);

    // Provided method
    fn count_items(_idx: Self::Value) -> usize { ... }
}

The index describes which fields we’re tracking, and can query. Indexes let us convert cursors to positions and vice versa.

Provided Associated Constants

const CAN_COUNT_ITEMS: bool = false

Required Associated Types

type Update: Debug + Default + PartialEq + Eq

type Value: Copy + Clone + Default + Debug + AddAssign + SubAssign + PartialEq + Eq + Sized

Required Methods

fn increment_marker(marker: &mut Self::Update, entry: &E)

fn decrement_marker(marker: &mut Self::Update, entry: &E)

fn decrement_marker_by_val(marker: &mut Self::Update, val: &Self::Value)

fn update_offset_by_marker(offset: &mut Self::Value, by: &Self::Update)

fn increment_offset(offset: &mut Self::Value, by: &E)

Provided Methods

fn count_items(_idx: Self::Value) -> usize

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.

Implementors

impl<E: ContentTraits + ContentLength> TreeMetrics<E> for ContentMetrics

type Update = isize

type Value = usize

impl<E: ContentTraits + ContentLength> TreeMetrics<E> for FullMetricsU32

const CAN_COUNT_ITEMS: bool = true

type Update = Pair<i32>

type Value = Pair<u32>

impl<E: ContentTraits + ContentLength> TreeMetrics<E> for FullMetricsUsize

const CAN_COUNT_ITEMS: bool = true

type Update = Pair<isize>

type Value = Pair<usize>

impl<E: ContentTraits> TreeMetrics<E> for RawPositionMetricsU32

const CAN_COUNT_ITEMS: bool = true

type Update = isize

type Value = u32

impl<E: ContentTraits> TreeMetrics<E> for RawPositionMetricsUsize

const CAN_COUNT_ITEMS: bool = true

type Update = isize

type Value = usize