Struct MapRef

pub struct MapRef<'a>(ListRef<'a>);

A map is just a slice of the underlying struct array.

Refer to MapArray for the invariants of a map value.

XXX: perhaps we can make it MapRef<'a, 'b>(ListRef<'a>, ListRef<'b>);. Then we can build a map ref from 2 list refs without copying the data. Currently it’s impossible. https://github.com/risingwavelabs/risingwave/issues/17863

Tuple Fields

0: ListRef<'a>

Implementations

impl<'a> MapRef<'a>

pub unsafe fn new_unchecked(list: ListRef<'a>) -> Self

Safety

The caller must ensure the invariants of a map value.

pub fn inner(&self) -> &ListRef<'a>

pub fn into_inner(self) -> ListRef<'a>

pub fn into_kv(self) -> (ListRef<'a>, ListRef<'a>)

pub fn keys(&self) -> HashSet<ScalarRefImpl<'_>>

pub fn to_owned(self) -> MapValue

pub fn len(&self) -> usize

pub fn is_empty(&self) -> bool

impl<'a> MapRef<'a>

pub fn iter( self, ) -> impl DoubleEndedIterator + ExactSizeIterator<Item = (ScalarRefImpl<'a>, DatumRef<'a>)> + 'a

Iterates over the elements of the map.

pub fn iter_struct( self, ) -> impl DoubleEndedIterator + ExactSizeIterator<Item = StructRef<'a>> + 'a

pub fn iter_sorted( self, ) -> impl DoubleEndedIterator + ExactSizeIterator<Item = (ScalarRefImpl<'a>, DatumRef<'a>)> + 'a

pub fn memcmp_serialize( self, serializer: &mut Serializer<impl BufMut>, ) -> Result<()>

Note: Map should not be used as key. But we don’t want to panic. See MapArray for the semantics. See also the Ord implementation. TODO: ban it in fe https://github.com/risingwavelabs/risingwave/issues/7981

Trait Implementations

impl<'a> Clone for MapRef<'a>

fn clone(&self) -> MapRef<'a>

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for MapRef<'_>

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

Formats the value using the given formatter.

impl<'scalar> From<MapRef<'scalar>> for ScalarRefImpl<'scalar>

fn from(val: MapRef<'scalar>) -> Self

Converts to this type from the input type.

impl Ord for MapRef<'_>

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 PartialEq for MapRef<'_>

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 PartialOrd for MapRef<'_>

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<'a> ScalarRef<'a> for MapRef<'a>

type ScalarType = MapValue

ScalarType is the owned type of current ScalarRef.

fn to_owned_scalar(&self) -> MapValue

Convert ScalarRef to an owned scalar.

fn hash_scalar<H: Hasher>(&self, state: &mut H)

A wrapped hash function to get the hash value for this scaler.

impl SelfAsScalarRef for MapRef<'_>

fn as_scalar_ref(&self) -> Self

impl ToText for MapRef<'_>

fn write<W: Write>(&self, f: &mut W) -> Result

Write the text to the writer regardless of its data type

fn write_with_type<W: Write>(&self, ty: &DataType, f: &mut W) -> Result

Write the text to the writer according to its data type

fn to_text_with_type(&self, ty: &DataType) -> String

Convert to text according to its data type

fn to_text(&self) -> String

to_text is a special version of to_text_with_type, it convert the scalar to default type text. E.g. for Int64, it will convert to text as a Int64 type. We should prefer to use to_text_with_type because it’s more clear and readable.

impl<'scalar> TryFrom<ScalarRefImpl<'scalar>> for MapRef<'scalar>

type Error = ArrayError

The type returned in the event of a conversion error.

fn try_from(val: ScalarRefImpl<'scalar>) -> ArrayResult<Self>

Performs the conversion.

impl<'a> Copy for MapRef<'a>

impl<'a> Eq for MapRef<'a>