Aggregate(TSource, TAccumulate, TResult) Method (ParallelQuery(TSource), Func(TAccumulate), Func(TAccumulate, TSource, TAccumulate), Func(TAccumulate, TAccumulate, TAccumulate), Func(TAccumulate, TResult))

From Task Parallel System.Threading

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Code: All Code: Multiple Code: Visual Basic Code: C#

Visual Basic C#

.NET Framework Class Library

ParallelEnumerable..::.Aggregate<(Of <(TSource, TAccumulate, TResult>)>) Method (ParallelQuery<(Of <(TSource>)>), Func<(Of <(TAccumulate>)>), Func<(Of <(TAccumulate, TSource, TAccumulate>)>), Func<(Of <(TAccumulate, TAccumulate, TAccumulate>)>), Func<(Of <(TAccumulate, TResult>)>))

ParallelEnumerable Class See Also Send Feedback

Applies in parallel an accumulator function over a sequence. This overload is not available in the sequential implementation.

Namespace: System.Linq
Assembly: System.Threading (in System.Threading.dll)

Syntax

Visual Basic (Declaration)
Public Shared Function Aggregate(Of TSource, TAccumulate, TResult) ( _ source As ParallelQuery(Of TSource), _ seedFactory As Func(Of TAccumulate), _ updateAccumulatorFunc As Func(Of TAccumulate, TSource, TAccumulate), _ combineAccumulatorsFunc As Func(Of TAccumulate, TAccumulate, TAccumulate), _ resultSelector As Func(Of TAccumulate, TResult) _ ) As TResult

Visual Basic (Declaration)

Public Shared Function Aggregate(Of TSource, TAccumulate, TResult) ( _
	source As ParallelQuery(Of TSource), _
	seedFactory As Func(Of TAccumulate), _
	updateAccumulatorFunc As Func(Of TAccumulate, TSource, TAccumulate), _
	combineAccumulatorsFunc As Func(Of TAccumulate, TAccumulate, TAccumulate), _
	resultSelector As Func(Of TAccumulate, TResult) _
) As TResult

C#
public static TResult Aggregate<TSource, TAccumulate, TResult>( ParallelQuery<TSource> source, Func<TAccumulate> seedFactory, Func<TAccumulate, TSource, TAccumulate> updateAccumulatorFunc, Func<TAccumulate, TAccumulate, TAccumulate> combineAccumulatorsFunc, Func<TAccumulate, TResult> resultSelector )

public static TResult Aggregate<TSource, TAccumulate, TResult>(
	ParallelQuery<TSource> source,
	Func<TAccumulate> seedFactory,
	Func<TAccumulate, TSource, TAccumulate> updateAccumulatorFunc,
	Func<TAccumulate, TAccumulate, TAccumulate> combineAccumulatorsFunc,
	Func<TAccumulate, TResult> resultSelector
)

Parameters

source: Type: System.Linq..::.ParallelQuery<(Of <(TSource>)>)
A sequence to aggregate over.

seedFactory: Type: System..::.Func<(Of <(TAccumulate>)>)
A function that returns the initial accumulator value.

updateAccumulatorFunc: Type: System..::.Func<(Of <(TAccumulate, TSource, TAccumulate>)>)
An accumulator function to be invoked on each element in a partition.

combineAccumulatorsFunc: Type: System..::.Func<(Of <(TAccumulate, TAccumulate, TAccumulate>)>)
An accumulator function to be invoked on the yielded element from each partition.

resultSelector: Type: System..::.Func<(Of <(TAccumulate, TResult>)>)
A function to transform the final accumulator value into the result value.

Type Parameters

TSource: The type of the elements of source.
TAccumulate: The type of the accumulator value.
TResult: The type of the resulting value.

Return Value

The transformed final accumulator value.

Remarks

This overload is specific to parallelized queries. A parallelized query may partition the data source sequence into several sub-sequences (partitions). The updateAccumulatorFunc is invoked on each element within partitions. Each partition then yields a single accumulated result. The combineAccumulatorsFunc is then invoked on the results of each partition to yield a single element. This element is then transformed by the resultSelector function.

Exceptions

Exception	Condition
System..::.ArgumentNullException	source or seedFactory or updateAccumulatorFunc or combineAccumulatorsFunc or resultSelector is a null reference (Nothing in Visual Basic).
System..::.AggregateException	One or more exceptions occurred during the evaluation of the query.
System..::.OperationCanceledException	The query was canceled.