Struct Cursor 

pub struct Cursor<T: CursorValues> {
    offset: usize,
    values: T,
}

A comparable cursor, used by sort operations

A Cursor is a pointer into a collection of rows, stored in CursorValues

┌───────────────────────┐
│                       │           ┌──────────────────────┐
│ ┌─────────┐ ┌─────┐   │    ─ ─ ─ ─│      Cursor<T>       │
│ │    1    │ │  A  │   │   │       └──────────────────────┘
│ ├─────────┤ ├─────┤   │
│ │    2    │ │  A  │◀─ ┼ ─ ┘          Cursor<T> tracks an
│ └─────────┘ └─────┘   │                offset within a
│     ...       ...     │                  CursorValues
│                       │
│ ┌─────────┐ ┌─────┐   │
│ │    3    │ │  E  │   │
│ └─────────┘ └─────┘   │
│                       │
│     CursorValues      │
└───────────────────────┘


Store logical rows using
one of several  formats,
with specialized
implementations
depending on the column
types

Fields

offset: usize

values: T

Implementations

impl<T: CursorValues> Cursor<T>

pub fn new(values: T) -> Self

Create a Cursor from the given CursorValues

pub fn is_finished(&self) -> bool

Returns true if there are no more rows in this cursor

pub fn advance(&mut self) -> usize

Advance the cursor, returning the previous row index

pub fn is_eq_to_prev_one(&self, prev_cursor: Option<&Cursor<T>>) -> bool

impl<T: CursorValues> Cursor<T>

fn is_eq_to_prev_row(&self) -> bool

fn is_eq_to_prev_row_in_prev_batch(&self, other: &Self) -> bool

Trait Implementations

impl<T: Debug + CursorValues> Debug for Cursor<T>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<T: CursorValues> Ord for Cursor<T>

fn cmp(&self, other: &Self) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

where Self: Sized,

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

where Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

where Self: Sized,

Restrict a value to a certain interval.

impl<T: CursorValues> PartialEq for Cursor<T>

fn eq(&self, other: &Self) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl<T: CursorValues> PartialOrd for Cursor<T>

fn partial_cmp(&self, other: &Self) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

fn lt(&self, other: &Rhs) -> bool

Tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &Rhs) -> bool

Tests less than or equal to (for self and other) and is used by the <= operator.

fn gt(&self, other: &Rhs) -> bool

Tests greater than (for self and other) and is used by the > operator.

fn ge(&self, other: &Rhs) -> bool

Tests greater than or equal to (for self and other) and is used by the >= operator.

impl<T: CursorValues> Eq for Cursor<T>