Struct arrow_array::Scalar

pub struct Scalar<T: Array>(/* private fields */);

A wrapper around a single value Array that implements Datum and indicates compute kernels should treat this array as a scalar value (a single value).

Using a Scalar is often much more efficient than creating an Array with the same (repeated) value.

See Datum for more information.

Example

// Create a (typed) scalar for Int32Array for the value 42
let scalar = Scalar::new(Int32Array::from(vec![42]));

// Create a scalar using PrimtiveArray::scalar
let scalar = Int32Array::new_scalar(42);

// create a scalar from an ArrayRef (for dynamic typed Arrays)
let array: ArrayRef = get_array();
let scalar = Scalar::new(array);

Implementations

impl<T: Array> Scalar<T>

pub fn new(array: T) -> Self

Create a new Scalar from an Array

Panics

Panics if array.len() != 1

Trait Implementations

impl<T: Clone + Array> Clone for Scalar<T>

fn clone(&self) -> Scalar<T>

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<T: Array> Datum for Scalar<T>

fn get(&self) -> (&dyn Array, bool)

Returns the value for this Datum and a boolean indicating if the value is scalar

impl<T: Debug + Array> Debug for Scalar<T>

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

Formats the value using the given formatter.

impl<T: Copy + Array> Copy for Scalar<T>