Trait Reducer

Source

pub trait Reducer:
    Send
    + Sync
    + Clone
    + 'static {
    type Dtype: PolarsDataType;
    type Value: Clone + Send + Sync + 'static;

    // Required methods
    fn init(&self) -> Self::Value;
    fn combine(&self, a: &mut Self::Value, b: &Self::Value);
    fn reduce_one(
        &self,
        a: &mut Self::Value,
        b: Option<<Self::Dtype as PolarsDataType>::Physical<'_>>,
    );
    fn reduce_ca(&self, v: &mut Self::Value, ca: &ChunkedArray<Self::Dtype>);
    fn finish(
        &self,
        v: Vec<Self::Value>,
        m: Option<Bitmap>,
        dtype: &DataType,
    ) -> PolarsResult<Series>;

    // Provided method
    fn cast_series<'a>(&self, s: &'a Series) -> Cow<'a, Series> { ... }
}