Struct polars::export::arrow::array::Utf8Array

source · [−]
pub struct Utf8Array<O> where
    O: Offset,  { /* private fields */ }
Expand description

A Utf8Array is arrow’s equivalent of an immutable Vec<Option<String>>. Cloning and slicing this struct is O(1).

Example

use arrow2::array::Utf8Array;
let array = Utf8Array::<i32>::from([Some("hi"), None, Some("there")]);
assert_eq!(array.value(0), "hi");
assert_eq!(array.values().as_slice(), b"hithere".as_ref());
assert_eq!(array.offsets().as_slice(), &[0, 2, 2, 2 + 5]);

Safety

The following invariants hold:

  • Two consecutives offsets casted (as) to usize are valid slices of values.
  • A slice of values taken from two consecutives offsets is valid utf8.
  • len is equal to validity.len(), when defined.

Implementations

Creates a new Utf8Array from a slice of &str. This is a convenience method that just calls Self::from_trusted_len_values_iter.

Creates a new Utf8Array from a slice of &str.

Creates a new Utf8Array from a TrustedLen of &str.

Creates a new Utf8Array from a Iterator of &str.

Creates a Utf8Array from an iterator of trusted length.

Safety

The iterator must be TrustedLen. I.e. that size_hint().1 correctly reports its length.

Creates a Utf8Array from an iterator of trusted length.

Creates a Utf8Array from an falible iterator of trusted length.

Safety

The iterator must be TrustedLen. I.e. that size_hint().1 correctly reports its length.

Creates a Utf8Array from an fallible iterator of trusted length.

Returns an iterator of Option<&str>

Returns an iterator of &str

Returns a new Utf8Array.

Errors

This function returns an error iff:

  • the offsets are not monotonically increasing
  • The last offset is not equal to the values’ length.
  • the validity’s length is not equal to offsets.len() - 1.
  • The data_type’s crate::datatypes::PhysicalType is not equal to either Utf8 or LargeUtf8.
  • The values between two consecutive offsets are not valid utf8
Implementation

This function is O(N) - checking monotinicity and utf8 is O(N)

Creates a new Utf8Array.

Panics

This function panics iff:

  • the offsets are not monotonically increasing
  • The last offset is not equal to the values’ length.
  • the validity’s length is not equal to offsets.len() - 1.
  • The data_type’s crate::datatypes::PhysicalType is not equal to either Utf8 or LargeUtf8.
  • The values between two consecutive offsets are not valid utf8
Implementation

This function is O(N) - checking monotinicity and utf8 is O(N)

Alias for new

Returns a new empty Utf8Array.

Returns a new Utf8Array whose all slots are null / None.

Returns the default DataType, DataType::Utf8 or DataType::LargeUtf8

Creates a new Utf8Array without checking for offsets monotinicity nor utf8-validity

Errors

This function returns an error iff:

  • The last offset is not equal to the values’ length.
  • the validity’s length is not equal to offsets.len() - 1.
  • The data_type’s crate::datatypes::PhysicalType is not equal to either Utf8 or LargeUtf8.
Safety

This function is unsound iff:

  • the offsets are not monotonically increasing
  • The values between two consecutive offsets are not valid utf8
Implementation

This function is O(1)

Creates a new Utf8Array without checking for offsets monotinicity.

Errors

This function returns an error iff:

  • The last offset is not equal to the values’ length.
  • the validity’s length is not equal to offsets.len() - 1.
  • The data_type’s crate::datatypes::PhysicalType is not equal to either Utf8 or LargeUtf8.
Safety

This function is unsound iff:

  • the offsets are not monotonically increasing
  • The values between two consecutive offsets are not valid utf8
Implementation

This function is O(1)

Alias for [new_unchecked]

Safety

This function is unsafe iff:

  • the offsets are not monotonically increasing
  • The values between two consecutive offsets are not valid utf8

Returns a slice of this Utf8Array.

Implementation

This operation is O(1) as it amounts to essentially increase two ref counts.

Panic

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

Returns a slice of this Utf8Array.

Implementation

This operation is O(1) as it amounts to essentially increase two ref counts.

Safety

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

Sets the validity bitmap on this Utf8Array.

Panic

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

Try to convert this Utf8Array to a MutableUtf8Array

Returns the length of this array

Returns the element at index i as &str

Safety

This function is safe iff i < self.len.

Returns the element at index i

The optional validity.

Returns the offsets of this Utf8Array.

Returns the values of this Utf8Array.

Trait Implementations

Convert to trait object.

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

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

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. Read more

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

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

Sets the validity bitmap on this Array. Read more

whether the array is empty

The number of null slots on this Array. Read more

Returns whether slot i is null. Read more

Returns whether slot i is valid. Read more

Apply kernel and return result as a new ChunkedArray.

Apply a kernel that outputs an array of different type.

Returns a copy of the value. Read more

Performs copy-assignment from source. Read more

Formats the value using the given formatter. Read more

Performs the conversion.

Performs the conversion.

Safety Read more

Creates a value from an iterator. Read more

The values of the array

The offsets of the array

The type of the elements being iterated over.

Which kind of iterator are we turning this into?

Creates an iterator from a value. Read more

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

This method tests for !=.

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

This method tests for !=.

Useful for a Utf8 or a List to get underlying value size. During a rechunk this is handy Read more

Auto Trait Implementations

Blanket Implementations

Gets the TypeId of self. Read more

Immutably borrows from an owned value. Read more

Mutably borrows from an owned value. Read more

Returns the argument unchanged.

Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

Safety Read more

Safety Read more

The alignment of pointer.

The type for initializers.

Initializes a with the given initializer. Read more

Dereferences the given pointer. Read more

Mutably dereferences the given pointer. Read more

Drops the object pointed to by the given pointer. Read more

The resulting type after obtaining ownership.

Creates owned data from borrowed data, usually by cloning. Read more

🔬 This is a nightly-only experimental API. (toowned_clone_into)

Uses borrowed data to replace owned data, usually by cloning. Read more

The type returned in the event of a conversion error.

Performs the conversion.

The type returned in the event of a conversion error.

Performs the conversion.