Trait polars::export::arrow::array::Array

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pub trait Array: Send + Sync {
    fn as_any(&self) -> &(dyn Any + 'static);
    fn len(&self) -> usize;
    fn data_type(&self) -> &DataType;
    fn validity(&self) -> Option<&Bitmap>;
    fn slice(
        &self, 
        offset: usize, 
        length: usize
    ) -> Box<dyn Array + 'static, Global>;
    unsafe fn slice_unchecked(
        &self, 
        offset: usize, 
        length: usize
    ) -> Box<dyn Array + 'static, Global>;
    fn with_validity(
        &self, 
        validity: Option<Bitmap>
    ) -> Box<dyn Array + 'static, Global>;
    fn to_boxed(&self) -> Box<dyn Array + 'static, Global>;

    fn is_empty(&self) -> bool { ... }
    fn null_count(&self) -> usize { ... }
    fn is_null(&self, i: usize) -> bool { ... }
    fn is_valid(&self, i: usize) -> bool { ... }
}

Expand description

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.

Required Methods

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

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 + 'static, Global>

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

Implementation

This operation is O(1) over len, as it amounts to increase two ref counts and moving the struct to the heap.

Panic

This function panics iff offset + length > self.len().

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

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

Implementation

This operation is O(1) over len, as it amounts to increase two ref counts and moving the struct to the heap.

Safety

The caller must ensure that offset + length <= self.len()

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

Sets the validity bitmap on this Array.

Panic

This function panics iff validity.len() < self.len().

fn to_boxed(&self) -> Box<dyn Array + 'static, Global>

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

Provided Methods

fn is_empty(&self) -> bool

whether the array is empty

fn null_count(&self) -> usize

The number of null slots on this Array.

Implementation

This is O(1).

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

Returns whether slot i is null.

Panic

Panics iff i >= self.len().

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

Returns whether slot i is valid.

Panic

Panics iff i >= self.len().

Trait Implementations

impl<'a> AsRef<dyn Array + 'a> for dyn Array + 'static

fn as_ref(&self) -> &(dyn Array + 'a)

Converts this type into a shared reference of the (usually inferred) input type.

impl<'_> Debug for dyn Array + '_