core/org.jetbrains.kotlinx.dataframe.impl.aggregation.aggregators/AggregatorInputHandler

AggregatorInputHandler

interface AggregatorInputHandler<in Value : Any, out Return> : AggregatorHandler<Value, Return>

The input handler of the aggregator, which handles type checks, conversions, and preprocessing of a single sequence of input values. It can also calculate a specific value type from the input values or input types if the (specific) type is not known.

Inheritors

Aggregator

AnyInputHandler

NumberInputHandler

Properties

aggregator

abstract var aggregator: Aggregator<Value, Return>?

Reference to the aggregator instance.

valueTypeIfEmpty

open val valueTypeIfEmpty: KType

The type of the value if the input is empty.

Functions

calculateValueType

abstract fun calculateValueType(valueTypes: Set<KType>): ValueType

If the specific ValueType of the input is not known, but you still want to call aggregate, this function can be called to calculate it by combining the set of known valueTypes.

abstract fun calculateValueType(values: Sequence<Value?>): ValueType

WARNING: HEAVY!

init

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

preprocessAggregation

abstract fun preprocessAggregation(values: Sequence<Value?>, valueType: ValueType): Pair<Sequence<Value?>, KType>

Preprocesses the input values before aggregation. It's expected that this function converts values to the right valueType.kType if valueType.needsFullConversion.