arrow::array::builder

Trait ArrayBuilder

pub trait ArrayBuilder:
    Any
    + Send
    + Sync {
    // Required methods
    fn len(&self) -> usize;
    fn finish(&mut self) -> Arc<dyn Array>;
    fn finish_cloned(&self) -> Arc<dyn Array>;
    fn as_any(&self) -> &(dyn Any + 'static);
    fn as_any_mut(&mut self) -> &mut (dyn Any + 'static);
    fn into_box_any(self: Box<Self>) -> Box<dyn Any>;

    // Provided method
    fn is_empty(&self) -> bool { ... }
}
Expand description

Trait for dealing with different array builders at runtime

§Example

// Create

let mut data_builders: Vec<Box<dyn ArrayBuilder>> = vec![
    Box::new(Float64Builder::new()),
    Box::new(Int64Builder::new()),
    Box::new(StringBuilder::new()),
];

// Fill
data_builders[0]
    .as_any_mut()
    .downcast_mut::<Float64Builder>()
    .unwrap()
    .append_value(3.14);
data_builders[1]
    .as_any_mut()
    .downcast_mut::<Int64Builder>()
    .unwrap()
    .append_value(-1);
data_builders[2]
    .as_any_mut()
    .downcast_mut::<StringBuilder>()
    .unwrap()
    .append_value("🍎");

// Finish
let array_refs: Vec<ArrayRef> = data_builders
    .iter_mut()
    .map(|builder| builder.finish())
    .collect();
assert_eq!(array_refs[0].len(), 1);
assert_eq!(array_refs[1].is_null(0), false);
assert_eq!(
    array_refs[2]
        .as_any()
        .downcast_ref::<StringArray>()
        .unwrap()
        .value(0),
    "🍎"
);

Required Methods§

fn len(&self) -> usize

Returns the number of array slots in the builder

fn finish(&mut self) -> Arc<dyn Array>

Builds the array

fn finish_cloned(&self) -> Arc<dyn Array>

Builds the array without resetting the underlying builder.

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

Returns the builder as a non-mutable Any reference.

This is most useful when one wants to call non-mutable APIs on a specific builder type. In this case, one can first cast this into a Any, and then use downcast_ref to get a reference on the specific builder.

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

Returns the builder as a mutable Any reference.

This is most useful when one wants to call mutable APIs on a specific builder type. In this case, one can first cast this into a Any, and then use downcast_mut to get a reference on the specific builder.

fn into_box_any(self: Box<Self>) -> Box<dyn Any>

Returns the boxed builder as a box of Any.

Provided Methods§

fn is_empty(&self) -> bool

Returns whether number of array slots is zero

Trait Implementations§

§

impl ArrayBuilder for Box<dyn ArrayBuilder>

§

fn len(&self) -> usize

Returns the number of array slots in the builder
§

fn is_empty(&self) -> bool

Returns whether number of array slots is zero
§

fn finish(&mut self) -> Arc<dyn Array>

Builds the array
§

fn finish_cloned(&self) -> Arc<dyn Array>

Builds the array without resetting the underlying builder.
§

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

Returns the builder as a non-mutable Any reference. Read more
§

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

Returns the builder as a mutable Any reference. Read more
§

fn into_box_any(self: Box<Box<dyn ArrayBuilder>>) -> Box<dyn Any>

Returns the boxed builder as a box of Any.

Implementations on Foreign Types§

§

impl ArrayBuilder for Box<dyn ArrayBuilder>

§

fn len(&self) -> usize

§

fn is_empty(&self) -> bool

§

fn finish(&mut self) -> Arc<dyn Array>

§

fn finish_cloned(&self) -> Arc<dyn Array>

§

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

§

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

§

fn into_box_any(self: Box<Box<dyn ArrayBuilder>>) -> Box<dyn Any>

Implementors§