Trait Cursor 

pub trait Cursor<'s> {
    type Item<'k>
       where Self: 'k;
    type Key: ?Sized;
    type ValueCursor: Cursor<'s>;

    // Required methods
    fn keys(&self) -> usize;
    fn item(&self) -> Self::Item<'_>;
    fn values(&self) -> Self::ValueCursor;
    fn step(&mut self);
    fn step_reverse(&mut self);
    fn seek(&mut self, key: &Self::Key);
    fn seek_reverse(&mut self, key: &Self::Key);
    fn valid(&self) -> bool;
    fn rewind(&mut self);
    fn fast_forward(&mut self);
    fn position(&self) -> usize;
    fn reposition(&mut self, lower: usize, upper: usize);
}

A type supporting navigation.

The precise meaning of this navigation is not defined by the trait. It is likely that having navigated around, the cursor will be different in some other way, but the Cursor trait does not explain how this is so.

Required Associated Types

type Item<'k> where Self: 'k

The type revealed by the cursor.

type Key: ?Sized

Key used to search the contents of the cursor.

type ValueCursor: Cursor<'s>

Required Methods

fn keys(&self) -> usize

fn item(&self) -> Self::Item<'_>

Reveals the current item.

fn values(&self) -> Self::ValueCursor

Returns cursor over values associted with the current key.

fn step(&mut self)

Advances the cursor by one element.

fn step_reverse(&mut self)

Move cursor back by one element.

fn seek(&mut self, key: &Self::Key)

Advances the cursor until the location where key would be expected.

fn seek_reverse(&mut self, key: &Self::Key)

Move the cursor back until the location where key would be expected.

fn valid(&self) -> bool

Returns true if the cursor points at valid data. Returns false if the cursor is exhausted.

fn rewind(&mut self)

Rewinds the cursor to its initial state.

fn fast_forward(&mut self)

Moves the cursor to the last position.

fn position(&self) -> usize

Current position of the cursor.

fn reposition(&mut self, lower: usize, upper: usize)

Repositions the cursor to a different range of values.

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety".

Implementations on Foreign Types

impl Cursor<'_> for ()

type Key = ()

type Item<'k> = &'k ()

type ValueCursor = ()

fn keys(&self) -> usize

fn item(&self) -> Self::Item<'_>

fn values(&self)

fn step(&mut self)

fn seek(&mut self, _key: &Self::Key)

fn valid(&self) -> bool

fn rewind(&mut self)

fn position(&self) -> usize

fn reposition(&mut self, _lower: usize, _upper: usize)

fn step_reverse(&mut self)

fn seek_reverse(&mut self, _key: &Self::Key)

fn fast_forward(&mut self)

Implementors

impl<'s, K, L, O> Cursor<'s> for LayerCursor<'s, K, L, O>

where K: DataTrait + ?Sized, L: Trie, O: OrdOffset,

type Key = K

type Item<'k> = &'k K where Self: 'k

type ValueCursor = <L as Trie>::Cursor<'s>

impl<'s, K: DataTrait + ?Sized, R: WeightTrait + ?Sized> Cursor<'s> for LeafCursor<'s, K, R>

type Item<'k> = (&'k K, &'k R) where Self: 'k

type Key = K

type ValueCursor = ()