Struct arrow::array::FixedSizeListArray

pub struct FixedSizeListArray { /* private fields */ }

A list array where each element is a fixed-size sequence of values with the same type whose maximum length is represented by a i32.

Example

// Construct a value array
let value_data = ArrayData::builder(DataType::Int32)
    .len(9)
    .add_buffer(Buffer::from_slice_ref(&[0, 1, 2, 3, 4, 5, 6, 7, 8]))
    .build()
    .unwrap();
let list_data_type = DataType::FixedSizeList(
    Box::new(Field::new("item", DataType::Int32, false)),
    3,
);
let list_data = ArrayData::builder(list_data_type.clone())
    .len(3)
    .add_child_data(value_data.clone())
    .build()
    .unwrap();
let list_array = FixedSizeListArray::from(list_data);
let list0 = list_array.value(0);
let list1 = list_array.value(1);
let list2 = list_array.value(2);

assert_eq!( &[0, 1, 2], list0.as_any().downcast_ref::<Int32Array>().unwrap().values());
assert_eq!( &[3, 4, 5], list1.as_any().downcast_ref::<Int32Array>().unwrap().values());
assert_eq!( &[6, 7, 8], list2.as_any().downcast_ref::<Int32Array>().unwrap().values());

For non generic lists, you may wish to consider using crate::array::FixedSizeBinaryArray

Implementations

impl FixedSizeListArray

pub fn values(&self) -> Arc<dyn Array + 'static>

Returns a reference to the values of this list.

pub fn value_type(&self) -> DataType

Returns a clone of the value type of this list.

pub fn value(&self, i: usize) -> Arc<dyn Array + 'static>

Returns ith value of this list array.

pub fn value_offset(&self, i: usize) -> i32

Returns the offset for value at index i.

Note this doesn’t do any bound checking, for performance reason.

pub const fn value_length(&self) -> i32

Returns the length for an element.

All elements have the same length as the array is a fixed size.

pub fn from_iter_primitive<T, P, I>(iter: I, length: i32) -> FixedSizeListArraywhere
    T: ArrowPrimitiveType,
    P: IntoIterator<Item = Option<<T as ArrowPrimitiveType>::Native>>,
    I: IntoIterator<Item = Option<P>>,

Creates a FixedSizeListArray from an iterator of primitive values

Example

let data = vec![
   Some(vec![Some(0), Some(1), Some(2)]),
   None,
   Some(vec![Some(3), None, Some(5)]),
   Some(vec![Some(6), Some(7), Some(45)]),
];
let list_array = FixedSizeListArray::from_iter_primitive::<Int32Type, _, _>(data, 3);
println!("{:?}", list_array);

Trait Implementations

impl Array for FixedSizeListArray

fn as_any(&self) -> &(dyn Any + 'static)

Returns the array as Any so that it can be downcasted to a specific implementation.

fn data(&self) -> &ArrayData

Returns a reference to the underlying data of this array.

fn into_data(self) -> ArrayData

Returns the underlying data of this array.

fn data_ref(&self) -> &ArrayData

Returns a reference-counted pointer to the underlying data of this array.

fn data_type(&self) -> &DataType

Returns a reference to the DataType of this array.

fn slice(&self, offset: usize, length: usize) -> Arc<dyn Array + 'static>

Returns a zero-copy slice of this array with the indicated offset and length.

fn len(&self) -> usize

Returns the length (i.e., number of elements) of this array.

fn is_empty(&self) -> bool

Returns whether this array is empty.

fn offset(&self) -> usize

Returns the offset into the underlying data used by this array(-slice). Note that the underlying data can be shared by many arrays. This defaults to 0.

fn is_null(&self, index: usize) -> bool

Returns whether the element at index is null. When using this function on a slice, the index is relative to the slice.

fn is_valid(&self, index: usize) -> bool

Returns whether the element at index is not null. When using this function on a slice, the index is relative to the slice.

fn null_count(&self) -> usize

Returns the total number of null values in this array.

fn get_buffer_memory_size(&self) -> usize

Returns the total number of bytes of memory pointed to by this array. The buffers store bytes in the Arrow memory format, and include the data as well as the validity map.

fn get_array_memory_size(&self) -> usize

Returns the total number of bytes of memory occupied physically by this array. This value will always be greater than returned by get_buffer_memory_size() and includes the overhead of the data structures that contain the pointers to the various buffers.

impl ArrayAccessor for FixedSizeListArray

type Item = Arc<dyn Array + 'static>

The Arrow type of the element being accessed.

fn value(&self, index: usize) -> <FixedSizeListArray as ArrayAccessor>::Item

Returns the element at index i

unsafe fn value_unchecked(
    &self,
    index: usize
) -> <FixedSizeListArray as ArrayAccessor>::Item

Returns the element at index i

impl Clone for FixedSizeListArray

fn clone(&self) -> FixedSizeListArray

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for FixedSizeListArray

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

Formats the value using the given formatter.

impl From<ArrayData> for FixedSizeListArray

fn from(data: ArrayData) -> FixedSizeListArray

Converts to this type from the input type.

impl From<FixedSizeListArray> for ArrayData

fn from(array: FixedSizeListArray) -> ArrayData

Converts to this type from the input type.

impl From<FixedSizeListArray> for FixedSizeBinaryArray

Creates a FixedSizeBinaryArray from FixedSizeList<u8> array

fn from(v: FixedSizeListArray) -> FixedSizeBinaryArray

Converts to this type from the input type.

impl PartialEq<FixedSizeListArray> for FixedSizeListArray

fn eq(&self, other: &FixedSizeListArray) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.