Struct ListBuilder

pub struct ListBuilder<'a> {
    parent_state: ParentState<'a>,
    offsets: Vec<usize>,
    parent_value_offset_base: usize,
    parent_metadata_offset_base: usize,
    has_been_finished: bool,
    validate_unique_fields: bool,
}

A builder for creating Variant::List values.

See the examples on VariantBuilder for usage.

Fields

parent_state: ParentState<'a>

offsets: Vec<usize>

parent_value_offset_base: usize

The starting offset in the parent’s buffer where this list starts

parent_metadata_offset_base: usize

The starting offset in the parent’s metadata buffer where this list starts used to truncate the written fields in drop if the current list has not been finished

has_been_finished: bool

Whether the list has been finished, the written content of the current list will be truncated in drop if has_been_finished is false

validate_unique_fields: bool

Implementations

impl<'a> ListBuilder<'a>

fn new(parent_state: ParentState<'a>, validate_unique_fields: bool) -> Self

pub fn with_validate_unique_fields(self, validate_unique_fields: bool) -> Self

Enables unique field key validation for objects created within this list.

Propagates the validation flag to any ObjectBuilders created using ListBuilder::new_object.

fn parent_state(&mut self) -> (ParentState<'_>, bool)

pub fn new_object(&mut self) -> ObjectBuilder<'_>

Returns an object builder that can be used to append a new (nested) object to this list.

WARNING: The builder will have no effect unless/until ObjectBuilder::finish is called.

pub fn new_list(&mut self) -> ListBuilder<'_>

Returns a list builder that can be used to append a new (nested) list to this list.

WARNING: The builder will have no effect unless/until ListBuilder::finish is called.

pub fn append_value<'m, 'd, T: Into<Variant<'m, 'd>>>(&mut self, value: T)

Appends a variant to the list.

Panics

This method will panic if the variant contains duplicate field names in objects when validation is enabled. For a fallible version, use ListBuilder::try_append_value.

pub fn try_append_value<'m, 'd, T: Into<Variant<'m, 'd>>>( &mut self, value: T, ) -> Result<(), ArrowError>

Appends a new primitive value to this list

pub fn with_value<'m, 'd, T: Into<Variant<'m, 'd>>>(self, value: T) -> Self

Builder-style API for appending a value to the list and returning self to enable method chaining.

Panics

This method will panic if the variant contains duplicate field names in objects when validation is enabled. For a fallible version, use ListBuilder::try_with_value.

pub fn try_with_value<'m, 'd, T: Into<Variant<'m, 'd>>>( self, value: T, ) -> Result<Self, ArrowError>

Builder-style API for appending a value to the list and returns self for method chaining.

This is the fallible version of ListBuilder::with_value.

pub fn finish(self)

Finalizes this list and appends it to its parent, which otherwise remains unmodified.

Trait Implementations

impl Drop for ListBuilder<'_>

Drop implementation for ListBuilder does nothing as the finish method must be called to finalize the list. This is to ensure that the list is always finalized before its parent builder is finalized.

fn drop(&mut self)

Executes the destructor for this type.

impl VariantBuilderExt for ListBuilder<'_>

fn append_value<'m, 'v>(&mut self, value: impl Into<Variant<'m, 'v>>)

fn new_list(&mut self) -> ListBuilder<'_>

fn new_object(&mut self) -> ObjectBuilder<'_>