Struct NdColumnBuilder 

pub struct NdColumnBuilder { /* private fields */ }

Collects nd arrays and encodes them into an NdColumn.

The attrs struct of the column holds the union of all attribute keys. A row without a key gets a null for it. The same key with two different types is an error.

Implementations

impl NdColumnBuilder

pub fn new() -> Self

A builder that takes the value type from the first array.

pub fn with_value_type(value_type: DataType) -> Self

A builder with a known value type, so that all-null and empty columns work.

pub fn with_value_field(value_field: FieldRef) -> Self

A builder with a custom item field for the values list.

pub fn len(&self) -> usize

The number of rows appended.

pub fn is_empty(&self) -> bool

True when no rows were appended.

pub fn append(&mut self, array: &NdArrowArray) -> Result<()>

Append one array as a row. Its value type must match the column.

pub fn append_null(&mut self)

Append a null row.

pub fn append_option(&mut self, array: Option<&NdArrowArray>) -> Result<()>

Append an array, or a null row for None.

pub fn finish(self) -> Result<NdColumn>

Encode the rows. Fails when no value type is known.

Trait Implementations

impl Debug for NdColumnBuilder

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

Formats the value using the given formatter.

impl Default for NdColumnBuilder

fn default() -> Self

Returns the “default value” for a type.