pub trait ArrayBuilder:
Any
+ Send
+ Sync {
// Required methods
fn len(&self) -> usize;
fn finish(&mut self) -> ArrayRef;
fn finish_cloned(&self) -> ArrayRef;
fn as_any(&self) -> &dyn Any;
fn as_any_mut(&mut self) -> &mut dyn Any;
fn into_box_any(self: Box<Self>) -> Box<dyn Any>;
// Provided methods
fn is_empty(&self) -> bool { ... }
fn finish_preserve_values(&mut self) -> ArrayRef { ... }
}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§
Sourcefn finish_cloned(&self) -> ArrayRef
fn finish_cloned(&self) -> ArrayRef
Builds the array without resetting the underlying builder.
Sourcefn as_any(&self) -> &dyn Any
fn as_any(&self) -> &dyn Any
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.
Sourcefn as_any_mut(&mut self) -> &mut dyn Any
fn as_any_mut(&mut self) -> &mut dyn Any
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.
Sourcefn into_box_any(self: Box<Self>) -> Box<dyn Any>
fn into_box_any(self: Box<Self>) -> Box<dyn Any>
Returns the boxed builder as a box of Any.
Provided Methods§
Sourcefn finish_preserve_values(&mut self) -> ArrayRef
fn finish_preserve_values(&mut self) -> ArrayRef
Builds the array without resetting the values builder.
This is relevant for dictionary builders but also for composite builders. Those are not affected directly, but will call the corresponding method on their constituent builders.
The default implementation just calls finish which is sufficient
for all but the above mentioned builders.
Trait Implementations§
Source§impl ArrayBuilder for Box<dyn ArrayBuilder>
impl ArrayBuilder for Box<dyn ArrayBuilder>
Source§fn finish_cloned(&self) -> ArrayRef
fn finish_cloned(&self) -> ArrayRef
Source§fn finish_preserve_values(&mut self) -> ArrayRef
fn finish_preserve_values(&mut self) -> ArrayRef
Source§fn as_any_mut(&mut self) -> &mut dyn Any
fn as_any_mut(&mut self) -> &mut dyn Any
Any reference. Read moreDyn Compatibility§
This trait is dyn compatible.
In older versions of Rust, dyn compatibility was called "object safety".