Struct FixedSizeListBuilder

pub struct FixedSizeListBuilder<T: ArrayBuilder> { /* private fields */ }

Builder for FixedSizeListArray

use arrow_array::{builder::{Int32Builder, FixedSizeListBuilder}, Array, Int32Array};
let values_builder = Int32Builder::new();
let mut builder = FixedSizeListBuilder::new(values_builder, 3);

//  [[0, 1, 2], null, [3, null, 5], [6, 7, null]]
builder.values().append_value(0);
builder.values().append_value(1);
builder.values().append_value(2);
builder.append(true);
builder.values().append_null();
builder.values().append_null();
builder.values().append_null();
builder.append(false);
builder.values().append_value(3);
builder.values().append_null();
builder.values().append_value(5);
builder.append(true);
builder.values().append_value(6);
builder.values().append_value(7);
builder.values().append_null();
builder.append(true);
let list_array = builder.finish();
assert_eq!(
    *list_array.value(0),
    Int32Array::from(vec![Some(0), Some(1), Some(2)])
);
assert!(list_array.is_null(1));
assert_eq!(
    *list_array.value(2),
    Int32Array::from(vec![Some(3), None, Some(5)])
);
assert_eq!(
    *list_array.value(3),
    Int32Array::from(vec![Some(6), Some(7), None])
)

Implementations

impl<T: ArrayBuilder> FixedSizeListBuilder<T>

pub fn new(values_builder: T, value_length: i32) -> Self

Creates a new FixedSizeListBuilder from a given values array builder value_length is the number of values within each array

pub fn with_capacity( values_builder: T, value_length: i32, capacity: usize, ) -> Self

Creates a new FixedSizeListBuilder from a given values array builder value_length is the number of values within each array capacity is the number of items to pre-allocate space for in this builder

pub fn with_field(self, field: impl Into<FieldRef>) -> Self

Override the field passed to FixedSizeListArray::new

By default, a nullable field is created with the name item

Note: Self::finish and Self::finish_cloned will panic if the field’s data type does not match that of T

impl<T> FixedSizeListBuilder<T>

where T: 'static + ArrayBuilder,

pub fn values(&mut self) -> &mut T

Returns the child array builder as a mutable reference.

This mutable reference can be used to append values into the child array builder, but you must call append to delimit each distinct list value.

pub fn value_length(&self) -> i32

Returns the length of the list

pub fn append(&mut self, is_valid: bool)

Finish the current fixed-length list array slot

pub fn finish(&mut self) -> FixedSizeListArray

Builds the FixedSizeListBuilder and reset this builder.

pub fn finish_cloned(&self) -> FixedSizeListArray

Builds the FixedSizeListBuilder without resetting the builder.

pub fn validity_slice(&self) -> Option<&[u8]>

Returns the current null buffer as a slice

Trait Implementations

impl<T> ArrayBuilder for FixedSizeListBuilder<T>

where T: 'static + ArrayBuilder,

fn as_any(&self) -> &dyn Any

Returns the builder as a non-mutable Any reference.

fn as_any_mut(&mut self) -> &mut dyn Any

Returns the builder as a mutable Any reference.

fn into_box_any(self: Box<Self>) -> Box<dyn Any>

Returns the boxed builder as a box of Any.

fn len(&self) -> usize

Returns the number of array slots in the builder

fn finish(&mut self) -> ArrayRef

Builds the array and reset this builder.

fn finish_cloned(&self) -> ArrayRef

Builds the array without resetting the builder.

fn is_empty(&self) -> bool

Returns whether number of array slots is zero

impl<T: Debug + ArrayBuilder> Debug for FixedSizeListBuilder<T>

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

Formats the value using the given formatter.