Struct arrow2::array::DictionaryArray

pub struct DictionaryArray<K: DictionaryKey> { /* private fields */ }

An Array whose values are encoded by keys. This Array is useful when the cardinality of values is low compared to the length of the Array.

Implementations

impl<'a, K: DictionaryKey> DictionaryArray<K>

pub fn iter(
    &'a self
) -> ZipValidity<'a, Box<dyn Scalar>, DictionaryValuesIter<'a, K>>

Returns an iterator of Option<Box<dyn Array>>

pub fn values_iter(&'a self) -> DictionaryValuesIter<'a, K>

Returns an iterator of Box<dyn Array>

impl<K: DictionaryKey> DictionaryArray<K>

pub fn new_empty(data_type: DataType) -> Self

Returns a new empty DictionaryArray.

pub fn new_null(data_type: DataType, length: usize) -> Self

Returns an DictionaryArray whose all elements are null

pub fn from_data(keys: PrimitiveArray<K>, values: Arc<dyn Array>) -> Self

The canonical method to create a new DictionaryArray.

pub fn slice(&self, offset: usize, length: usize) -> Self

Creates a new DictionaryArray by slicing the existing DictionaryArray.

Panics

iff offset + length > self.len().

pub unsafe fn slice_unchecked(&self, offset: usize, length: usize) -> Self

Creates a new DictionaryArray by slicing the existing DictionaryArray.

Safety

Safe iff offset + length <= self.len().

pub fn with_validity(&self, validity: Option<Bitmap>) -> Self

Sets the validity bitmap on this Array.

Panic

This function panics iff validity.len() != self.len().

impl<K: DictionaryKey> DictionaryArray<K>

pub fn len(&self) -> usize

Returns the length of this array

pub fn validity(&self) -> Option<&Bitmap>

The optional validity. Equivalent to self.keys().validity().

pub fn keys(&self) -> &PrimitiveArray<K>

Returns the keys of the DictionaryArray. These keys can be used to fetch values from values.

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

Returns the values of the DictionaryArray.

pub fn value(&self, index: usize) -> Box<dyn Scalar>

Returns the value of the DictionaryArray at position i.

Trait Implementations

impl<K: DictionaryKey> Array for DictionaryArray<K>

fn as_any(&self) -> &dyn Any

Convert to trait object.

fn len(&self) -> usize

The length of the Array. Every array has a length corresponding to the number of elements (slots).

fn data_type(&self) -> &DataType

The DataType of the Array. In combination with Array::as_any, this can be used to downcast trait objects (dyn Array) to concrete arrays.

fn validity(&self) -> Option<&Bitmap>

The validity of the Array: every array has an optional Bitmap that, when available specifies whether the array slot is valid or not (null). When the validity is None, all slots are valid.

fn slice(&self, offset: usize, length: usize) -> Box<dyn Array>

Slices the Array, returning a new Box<dyn Array>.

unsafe fn slice_unchecked(&self, offset: usize, length: usize) -> Box<dyn Array>

Slices the Array, returning a new Box<dyn Array>.

fn with_validity(&self, validity: Option<Bitmap>) -> Box<dyn Array>

Sets the validity bitmap on this Array.

fn to_boxed(&self) -> Box<dyn Array>

Clone a &dyn Array to an owned Box<dyn Array>.

fn is_empty(&self) -> bool

whether the array is empty

fn null_count(&self) -> usize

The number of null slots on this Array.

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

Returns whether slot i is null.

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

Returns whether slot i is valid.

impl<K: Clone + DictionaryKey> Clone for DictionaryArray<K>

fn clone(&self) -> DictionaryArray<K>

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<K: DictionaryKey> Debug for DictionaryArray<K>

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

Formats the value using the given formatter.

impl<'a, T: DictionaryKey> From<GrowableDictionary<'a, T>> for DictionaryArray<T>

fn from(val: GrowableDictionary<'a, T>) -> Self

Converts to this type from the input type.

impl<K: DictionaryKey, M: MutableArray> From<MutableDictionaryArray<K, M>> for DictionaryArray<K>

fn from(other: MutableDictionaryArray<K, M>) -> Self

Converts to this type from the input type.

impl<'a, K: DictionaryKey> IntoIterator for &'a DictionaryArray<K>

type Item = Option<Box<dyn Scalar + 'static, Global>>

The type of the elements being iterated over.

type IntoIter = ZipValidity<'a, Box<dyn Scalar + 'static, Global>, DictionaryValuesIter<'a, K>>

Which kind of iterator are we turning this into?

fn into_iter(self) -> Self::IntoIter

Creates an iterator from a value.

impl<K: DictionaryKey> PartialEq<&'_ (dyn Array + '_)> for DictionaryArray<K>

fn eq(&self, other: &&dyn Array) -> 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 !=.

impl<K: DictionaryKey> PartialEq<DictionaryArray<K>> for DictionaryArray<K>

fn eq(&self, other: &Self) -> 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 !=.