core/org.jetbrains.kotlinx.dataframe.impl.aggregation.aggregators.multipleColumnsHandlers/FlatteningMultipleColumnsHandler

FlatteningMultipleColumnsHandler

internal class FlatteningMultipleColumnsHandler<in Value : Any, out Return> : AggregatorMultipleColumnsHandler<Value, Return>

Implementation of AggregatorMultipleColumnsHandler that simply flattens all input columns. This is useful for aggregators that depend on the distribution of values across multiple columns.

Constructors

constructor()

Properties

aggregator

open override var aggregator: Aggregator<Value, Return>?

Reference to the aggregator instance.

Functions

aggregateMultipleColumns

open override fun aggregateMultipleColumns(columns: Sequence<DataColumn<Value?>>): Return

Aggregates the data in the multiple given columns and computes a single resulting value. The columns are flattened into a single list of values; then the aggregation function is called with the common type of the columns.

calculateReturnTypeMultipleColumns

open override fun calculateReturnTypeMultipleColumns(colTypes: Set<KType>, colsEmpty: Boolean): KType

Function that can give the return type of aggregateMultipleColumns, given types of the columns. This allows aggregators to avoid runtime type calculations.

init

open fun init(aggregator: Aggregator<Value, Return>)

FlatteningMultipleColumnsHandler

See also

Constructors

Properties

Functions