Enum RKeyFunction 

#[non_exhaustive]
pub enum RKeyFunction {
    KeyExact,
    KeyOrNext,
    KeyOrPrev,
    AfterKey,
    BeforeKey,
    Prefix,
    PrefixLast,
    PrefixLastOrPrev,
    MbrContain,
    MbrIntersect,
    MbrWithin,
    MbrDisjoint,
    MbrEqual,
    NearestNeighbor,
    Invalid,
}

Search semantics for an index lookup, mirroring MySQL’s ha_rkey_function.

Passed to StorageEngine::index_read_map to describe how the supplied key should be matched: an exact hit, the nearest neighbour in a direction, a prefix, or one of the spatial (minimum-bounding-rectangle) relations.

Variants (Non-exhaustive)

Non-exhaustive enums could have additional variants added in future. Therefore, when matching against variants of non-exhaustive enums, an extra wildcard arm must be added to account for any future variants.

KeyExact

Find the first record with exactly this key, else error

KeyOrNext

This record or the next one

KeyOrPrev

This record or the previous one

AfterKey

First record after this key

BeforeKey

First record before this key

Prefix

First record sharing this key prefix

PrefixLast

Last record sharing this key prefix

PrefixLastOrPrev

Last record with this prefix, or the previous one

MbrContain

Minimum bounding rectangle contains the key

MbrIntersect

Minimum bounding rectangle intersects the key

MbrWithin

Minimum bounding rectangle is within the key

MbrDisjoint

Minimum bounding rectangle is disjoint from the key

MbrEqual

Minimum bounding rectangle equals the key

NearestNeighbor

Nearest-neighbour spatial search

Invalid

Unrecognised value; MySQL’s HA_READ_INVALID or an out-of-range code

Trait Implementations

impl Clone for RKeyFunction

fn clone(&self) -> RKeyFunction

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Copy for RKeyFunction

impl Debug for RKeyFunction

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

Formats the value using the given formatter.

impl Eq for RKeyFunction

impl PartialEq for RKeyFunction

fn eq(&self, other: &RKeyFunction) -> 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 StructuralPartialEq for RKeyFunction