Struct arrow::datatypes::UnionFields

pub struct UnionFields(/* private fields */);

A cheaply cloneable, owned collection of FieldRef and their corresponding type ids

Implementations

impl UnionFields

pub fn empty() -> UnionFields

Create a new UnionFields with no fields

pub fn new<F, T>(type_ids: T, fields: F) -> UnionFields

where F: IntoIterator, <F as IntoIterator>::Item: Into<Arc<Field>>, T: IntoIterator<Item = i8>,

Create a new UnionFields from a Fields and array of type_ids

See https://arrow.apache.org/docs/format/Columnar.html#union-layout

use arrow_schema::{DataType, Field, UnionFields};
// Create a new UnionFields with type id mapping
// 1 -> DataType::UInt8
// 3 -> DataType::Utf8
UnionFields::new(
    vec![1, 3],
    vec![
        Field::new("field1", DataType::UInt8, false),
        Field::new("field3", DataType::Utf8, false),
    ],
);

pub fn size(&self) -> usize

Return size of this instance in bytes.

pub fn len(&self) -> usize

Returns the number of fields in this UnionFields

pub fn is_empty(&self) -> bool

Returns true if this is empty

pub fn iter(&self) -> impl Iterator<Item = (i8, &Arc<Field>)>

Returns an iterator over the fields and type ids in this UnionFields

Note: the iteration order is not guaranteed

Trait Implementations

impl Clone for UnionFields

fn clone(&self) -> UnionFields

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for UnionFields

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

Formats the value using the given formatter.

impl FromIterator<(i8, Arc<Field>)> for UnionFields

fn from_iter<T>(iter: T) -> UnionFields

where T: IntoIterator<Item = (i8, Arc<Field>)>,

Creates a value from an iterator.

impl Hash for UnionFields

fn hash<__H>(&self, state: &mut __H)

where __H: Hasher,

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl Ord for UnionFields

fn cmp(&self, other: &UnionFields) -> 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 + PartialOrd,

Restrict a value to a certain interval.

impl PartialEq for UnionFields

fn eq(&self, other: &UnionFields) -> 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 UnionFields

fn partial_cmp(&self, other: &UnionFields) -> 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 Eq for UnionFields

impl StructuralPartialEq for UnionFields