Struct arrow::array::builder::MapBuilder
pub struct MapBuilder<K, V>where
K: ArrayBuilder,
V: ArrayBuilder,{
offsets_builder: BufferBuilder<i32>,
null_buffer_builder: NullBufferBuilder,
field_names: MapFieldNames,
key_builder: K,
value_builder: V,
value_field: Option<Arc<Field>>,
}
Expand description
Builder for MapArray
let string_builder = StringBuilder::new();
let int_builder = Int32Builder::with_capacity(4);
// Construct `[{"joe": 1}, {"blogs": 2, "foo": 4}, {}, null]`
let mut builder = MapBuilder::new(None, string_builder, int_builder);
builder.keys().append_value("joe");
builder.values().append_value(1);
builder.append(true).unwrap();
builder.keys().append_value("blogs");
builder.values().append_value(2);
builder.keys().append_value("foo");
builder.values().append_value(4);
builder.append(true).unwrap();
builder.append(true).unwrap();
builder.append(false).unwrap();
let array = builder.finish();
assert_eq!(array.value_offsets(), &[0, 1, 3, 3, 3]);
assert_eq!(array.values().as_ref(), &Int32Array::from(vec![1, 2, 4]));
assert_eq!(array.keys().as_ref(), &StringArray::from(vec!["joe", "blogs", "foo"]));
Fields§
§offsets_builder: BufferBuilder<i32>
§null_buffer_builder: NullBufferBuilder
§field_names: MapFieldNames
§key_builder: K
§value_builder: V
§value_field: Option<Arc<Field>>
Implementations§
§impl<K, V> MapBuilder<K, V>where
K: ArrayBuilder,
V: ArrayBuilder,
impl<K, V> MapBuilder<K, V>where
K: ArrayBuilder,
V: ArrayBuilder,
pub fn new(
field_names: Option<MapFieldNames>,
key_builder: K,
value_builder: V,
) -> MapBuilder<K, V>
pub fn new( field_names: Option<MapFieldNames>, key_builder: K, value_builder: V, ) -> MapBuilder<K, V>
Creates a new MapBuilder
pub fn with_capacity(
field_names: Option<MapFieldNames>,
key_builder: K,
value_builder: V,
capacity: usize,
) -> MapBuilder<K, V>
pub fn with_capacity( field_names: Option<MapFieldNames>, key_builder: K, value_builder: V, capacity: usize, ) -> MapBuilder<K, V>
Creates a new MapBuilder
with capacity
pub fn with_values_field(self, field: impl Into<Arc<Field>>) -> MapBuilder<K, V>
pub fn with_values_field(self, field: impl Into<Arc<Field>>) -> MapBuilder<K, V>
Override the field passed to MapBuilder::new
By default a nullable field is created with the name values
Note: Self::finish
and Self::finish_cloned
will panic if the
field’s data type does not match that of V
pub fn entries(&mut self) -> (&mut K, &mut V)
pub fn entries(&mut self) -> (&mut K, &mut V)
Returns both the key and value array builders of the map
pub fn append(&mut self, is_valid: bool) -> Result<(), ArrowError>
pub fn append(&mut self, is_valid: bool) -> Result<(), ArrowError>
Finish the current map array slot
Returns an error if the key and values builders are in an inconsistent state.
pub fn finish_cloned(&self) -> MapArray
pub fn finish_cloned(&self) -> MapArray
Builds the MapArray
without resetting the builder.
pub fn validity_slice(&self) -> Option<&[u8]>
pub fn validity_slice(&self) -> Option<&[u8]>
Returns the current null buffer as a slice
Trait Implementations§
§impl<K, V> ArrayBuilder for MapBuilder<K, V>where
K: ArrayBuilder,
V: ArrayBuilder,
impl<K, V> ArrayBuilder for MapBuilder<K, V>where
K: ArrayBuilder,
V: ArrayBuilder,
§fn finish_cloned(&self) -> Arc<dyn Array>
fn finish_cloned(&self) -> Arc<dyn Array>
Builds the array without resetting the builder.
§fn as_any(&self) -> &(dyn Any + 'static)
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)
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<MapBuilder<K, V>>) -> Box<dyn Any>
fn into_box_any(self: Box<MapBuilder<K, V>>) -> Box<dyn Any>
Returns the boxed builder as a box of
Any
.§impl<K, V> Debug for MapBuilder<K, V>
impl<K, V> Debug for MapBuilder<K, V>
Auto Trait Implementations§
impl<K, V> Freeze for MapBuilder<K, V>
impl<K, V> RefUnwindSafe for MapBuilder<K, V>where
K: RefUnwindSafe,
V: RefUnwindSafe,
impl<K, V> Send for MapBuilder<K, V>
impl<K, V> Sync for MapBuilder<K, V>
impl<K, V> Unpin for MapBuilder<K, V>
impl<K, V> UnwindSafe for MapBuilder<K, V>where
K: UnwindSafe,
V: UnwindSafe,
Blanket Implementations§
source§impl<T> BorrowMut<T> for Twhere
T: ?Sized,
impl<T> BorrowMut<T> for Twhere
T: ?Sized,
source§fn borrow_mut(&mut self) -> &mut T
fn borrow_mut(&mut self) -> &mut T
Mutably borrows from an owned value. Read more