Enum DType 

pub enum DType {
    Bool,
    Int8,
    Int16,
    Int32,
    Int64,
    UInt8,
    UInt16,
    UInt32,
    UInt64,
    Float32,
    Float64,
    String,
    Binary,
    FixedSizeList {
        child: Box<DType>,
        size: u32,
    },
    List {
        child: Box<DType>,
    },
    TimestampNs,
}

Describes the element type of an array.

Variants

Bool

Boolean stored as 1 byte (0 or 1).

Int8

Signed 8-bit integer.

Int16

Signed 16-bit integer (little-endian).

Int32

Signed 32-bit integer (little-endian).

Int64

Signed 64-bit integer (little-endian).

UInt8

Unsigned 8-bit integer.

UInt16

Unsigned 16-bit integer (little-endian).

UInt32

Unsigned 32-bit integer (little-endian).

UInt64

Unsigned 64-bit integer (little-endian).

Float32

32-bit IEEE 754 floating point (little-endian).

Float64

64-bit IEEE 754 floating point (little-endian).

String

Variable-length UTF-8 string.

Encoded as an offsets buffer (N + 1 entries) followed by a concatenated values buffer.

Binary

Variable-length binary data (vlen bytes).

Encoded identically to DType::String but without UTF-8 semantics.

FixedSizeList

Fixed-size list where every element contains exactly size children.

No offsets buffer is needed; child values are stored contiguously.

Fields

child: Box<DType>

Element type of the child values.

size: u32

Number of child values per list element.

List

Variable-length list where each element can have a different number of children.

Encoded with a parent offsets buffer (N + 1 entries) and a concatenated child values buffer.

Fields

child: Box<DType>

Element type of the child values.

TimestampNs

64-bit nanosecond timestamp since the Unix epoch (little-endian).

Byte-identical to DType::Int64 but carries the “nanoseconds since 1970-01-01 UTC” meaning in the type system.

Implementations

impl DType

pub fn element_size(&self) -> Option<usize>

Returns the byte size of a single element for fixed-width types, or None for variable-length types.

pub fn is_variable_length(&self) -> bool

Returns true if the type requires an offsets buffer (i.e. it is variable-length).

Trait Implementations

impl Archive for DType

where u32: Archive,

type Archived = ArchivedDType

The archived representation of this type.

type Resolver = DTypeResolver

The resolver for this type. It must contain all the additional information from serializing needed to make the archived type from the normal type.

fn resolve( &self, resolver: <Self as Archive>::Resolver, out: Place<<Self as Archive>::Archived>, )

Creates the archived version of this value at the given position and writes it to the given output.

const COPY_OPTIMIZATION: CopyOptimization<Self> = _

An optimization flag that allows the bytes of this type to be copied directly to a writer instead of calling serialize.

impl Clone for DType

fn clone(&self) -> DType

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for DType

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

Formats the value using the given formatter.

impl<__D: Fallible + ?Sized> Deserialize<DType, __D> for Archived<DType>

where __D::Error: Source, u32: Archive, <u32 as Archive>::Archived: Deserialize<u32, __D>,

fn deserialize( &self, deserializer: &mut __D, ) -> Result<DType, <__D as Fallible>::Error>

Deserializes using the given deserializer

impl PartialEq for DType

fn eq(&self, other: &DType) -> 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<__S> Serialize<__S> for DType

where __S: Writer + Allocator + Fallible + ?Sized, __S::Error: Source, u32: Serialize<__S>,

fn serialize( &self, serializer: &mut __S, ) -> Result<<Self as Archive>::Resolver, <__S as Fallible>::Error>

Writes the dependencies for the object and returns a resolver that can create the archived type.

impl StructuralPartialEq for DType