Module array

Expand description

Contains the Array and MutableArray trait objects declaring arrays, as well as concrete arrays (such as Utf8Array and MutableUtf8Array).

Fixed-length containers with optional values that are layed in memory according to the Arrow specification. Each array type has its own struct. The following are the main array types:

PrimitiveArray and MutablePrimitiveArray, an array of values with a fixed length such as integers, floats, etc.
BooleanArray and MutableBooleanArray, an array of boolean values (stored as a bitmap)
Utf8Array and MutableUtf8Array, an array of variable length utf8 values
BinaryArray and MutableBinaryArray, an array of opaque variable length values
ListArray and MutableListArray, an array of arrays (e.g. [[1, 2], None, [], [None]])
StructArray and MutableStructArray, an array of arrays identified by a string (e.g. {"a": [1, 2], "b": [true, false]}) All immutable arrays implement the trait object Array and that can be downcasted to a concrete struct based on PhysicalType available from Array::data_type. All immutable arrays are backed by Buffer and thus cloning and slicing them is O(1).

Most arrays contain a MutableArray counterpart that is neither clonable nor slicable, but can be operated in-place.

Modules§

growable: Contains the trait Growable and corresponding concreate implementations, one per concrete array, that offer the ability to create a new Array out of slices of existing Arrays.
ord: Contains functions and function factories to order values within arrays.

Structs§

ArrayValuesIter: Iterator of values of an [ArrayAccessor].
BinaryArray: A BinaryArray is Arrow’s semantically equivalent of an immutable Vec<Option<Vec<u8>>>. It implements Array.
BooleanArray: A BooleanArray is Arrow’s semantically equivalent of an immutable Vec<Option<bool>>. It implements Array.
DictionaryArray: An Array whose values are stored as indices. This Array is useful when the cardinality of values is low compared to the length of the Array.
FixedSizeBinaryArray: The Arrow’s equivalent to an immutable Vec<Option<[u8; size]>>. Cloning and slicing this struct is O(1).
FixedSizeListArray: The Arrow’s equivalent to an immutable Vec<Option<[T; size]>> where T is an Arrow type. Cloning and slicing this struct is O(1).
ListArray: An Array semantically equivalent to Vec<Option<Vec<Option<T>>>> with Arrow’s in-memory.
MapArray: An array representing a (key, value), both of arbitrary logical types.
MutableBinaryArray: The Arrow’s equivalent to Vec<Option<Vec<u8>>>. Converting a MutableBinaryArray into a BinaryArray is O(1).
MutableBinaryValuesArray: A MutableArray that builds a BinaryArray. It differs from MutableBinaryArray in that it builds non-null BinaryArray.
MutableBooleanArray: The Arrow’s equivalent to Vec<Option<bool>>, but with 1/16 of its size. Converting a MutableBooleanArray into a BooleanArray is O(1).
MutableDictionaryArray: A mutable, strong-typed version of DictionaryArray.
MutableFixedSizeBinaryArray: The Arrow’s equivalent to a mutable Vec<Option<[u8; size]>>. Converting a MutableFixedSizeBinaryArray into a FixedSizeBinaryArray is O(1).
MutableFixedSizeListArray: The mutable version of FixedSizeListArray.
MutableListArray: The mutable version of ListArray.
MutableNullArray: A distinct type to disambiguate clashing methods
MutablePrimitiveArray: The Arrow’s equivalent to Vec<Option<T>> where T is byte-size (e.g. i32). Converting a MutablePrimitiveArray into a PrimitiveArray is O(1).
MutableStructArray: Converting a MutableStructArray into a StructArray is O(1).
MutableUtf8Array: A MutableArray that builds a Utf8Array. It differs from MutableUtf8ValuesArray in that it can build nullable Utf8Arrays.
MutableUtf8ValuesArray: A MutableArray that builds a Utf8Array. It differs from MutableUtf8Array in that it builds non-null Utf8Array.
NullArray: The concrete Array of DataType::Null.
PrimitiveArray: A PrimitiveArray is Arrow’s semantically equivalent of an immutable Vec<Option<T>> where T is NativeType (e.g. i32). It implements Array.
StructArray: A StructArray is a nested Array with an optional validity representing multiple Array with the same number of rows.
UnionArray: UnionArray represents an array whose each slot can contain different values.
Utf8Array: A Utf8Array is arrow’s semantic equivalent of an immutable Vec<Option<String>>. Cloning and slicing this struct is O(1).

Traits§

Array: A trait representing an immutable Arrow array. Arrow arrays are trait objects that are infallibly downcasted to concrete types according to the Array::data_type.
Arrow2Arrow: Trait providing bi-directional conversion between arrow2 Array and arrow-rs ArrayData
DictionaryKey: Trait denoting NativeTypes that can be used as keys of a dictionary.
GenericBinaryArray: Trait that BinaryArray and Utf8Array implement for the purposes of DRY.
MutableArray: A trait describing a mutable array; i.e. an array whose values can be changed. Mutable arrays cannot be cloned but can be mutated in place, thereby making them useful to perform numeric operations without allocations. As in Array, concrete arrays (such as MutablePrimitiveArray) implement how they are mutated.
PushUnchecked: A trait describing the ability of a struct to receive new items.
TryExtend: A trait describing the ability of a struct to create itself from a iterator. This is similar to Extend, but accepted the creation to error.
TryExtendFromSelf: A trait describing the ability of a struct to extend from a reference of itself. Specialization of TryExtend.
TryPush: A trait describing the ability of a struct to receive new items.

Functions§

clone: Clones a dynamic Array.
equal: Logically compares two Arrays. Two arrays are logically equal if and only if:
from_data: Convert an arrow_data::ArrayData to arrow2 Array
get_display: Returns a function that writes the element of array at position index to a Write, writing null to the null slots.
get_value_display: Returns a function that writes the value of the element of array at position index to a Write, writing null in the null slots.
new_empty_array: Creates a new Array with a Array::len of 0.
new_null_array: Creates a new Array of DataType data_type and length. The array is guaranteed to have Array::null_count equal to Array::len for all types except Union, which does not have a validity.
to_data: Convert an arrow2 Array to arrow_data::ArrayData

Type Aliases§