Struct UnionVariantToArrowRowBuilder 

pub(crate) struct UnionVariantToArrowRowBuilder<'a> {
    fields: &'a UnionFields,
    mode: UnionMode,
    children: Vec<UnionChildBuilder<'a>>,
    type_ids: Vec<i8>,
    offsets: Vec<i32>,
    null_child: usize,
    cast_options: &'a CastOptions<'a>,
}

Builder for converting variant values into a [UnionArray].

Each value is dispatched to the union field that most exactly represents its runtime type (see union_child_rank), with ties broken by declaration order. Unions have no top-level null buffer, so null rows – and, in safe mode, values no field can represent – become a null in the [DataType::Null] child if the union declares one, otherwise in the first child.

Fields

fields: &'a UnionFields

mode: UnionMode

children: Vec<UnionChildBuilder<'a>>

type_ids: Vec<i8>

offsets: Vec<i32>

Dense mode only

null_child: usize

cast_options: &'a CastOptions<'a>

Implementations

impl<'a> UnionVariantToArrowRowBuilder<'a>

fn try_new( fields: &'a UnionFields, mode: UnionMode, cast_options: &'a CastOptions<'a>, capacity: usize, ) -> Result<Self>

fn append_null(&mut self) -> Result<()>

fn append_value(&mut self, value: &Variant<'_, '_>) -> Result<bool>

fn select_child(&self, value: &Variant<'_, '_>) -> Option<usize>

fn append_to_child( &mut self, index: usize, value: Option<&Variant<'_, '_>>, ) -> Result<bool>

fn finish(self) -> Result<ArrayRef>