AsyncEnumerable.ToLookupAsync Method

Definition

Namespace:

System.Linq

Assembly:

System.Linq.AsyncEnumerable.dll

Package:

System.Linq.AsyncEnumerable v10.0.0-preview.1.25080.5

Overloads

ToLookupAsync<TSource,TKey,TElement>(IAsyncEnumerable<TSource>, Func<TSource,TKey>, Func<TSource,TElement>, IEqualityComparer<TKey>, CancellationToken)	Creates a ILookup<TKey,TElement> from an IAsyncEnumerable<T> according to a specified key selector function and element selector functions.
ToLookupAsync<TSource,TKey,TElement>(IAsyncEnumerable<TSource>, Func<TSource,CancellationToken,ValueTask<TKey>>, Func<TSource, CancellationToken,ValueTask<TElement>>, IEqualityComparer<TKey>, CancellationToken)	Creates a ILookup<TKey,TElement> from an IAsyncEnumerable<T> according to a specified key selector function and element selector functions.
ToLookupAsync<TSource,TKey>(IAsyncEnumerable<TSource>, Func<TSource,CancellationToken,ValueTask<TKey>>, IEqualityComparer<TKey>, CancellationToken)	Creates a ILookup<TKey,TElement> from an IAsyncEnumerable<T> according to a specified key selector function.
ToLookupAsync<TSource,TKey>(IAsyncEnumerable<TSource>, Func<TSource,TKey>, IEqualityComparer<TKey>, CancellationToken)	Creates a ILookup<TKey,TElement> from an IAsyncEnumerable<T> according to a specified key selector function.

ToLookupAsync<TSource,TKey,TElement>(IAsyncEnumerable<TSource>, Func<TSource,TKey>, Func<TSource,TElement>, IEqualityComparer<TKey>, CancellationToken)

Source:

ToLookupAsync.cs

Creates a ILookup<TKey,TElement> from an IAsyncEnumerable<T> according to a specified key selector function and element selector functions.

public static System.Threading.Tasks.ValueTask<System.Linq.ILookup<TKey,TElement>> ToLookupAsync<TSource,TKey,TElement>(this System.Collections.Generic.IAsyncEnumerable<TSource> source, Func<TSource,TKey> keySelector, Func<TSource,TElement> elementSelector, System.Collections.Generic.IEqualityComparer<TKey>? comparer = default, System.Threading.CancellationToken cancellationToken = default);

static member ToLookupAsync : System.Collections.Generic.IAsyncEnumerable<'Source> * Func<'Source, 'Key> * Func<'Source, 'Element> * System.Collections.Generic.IEqualityComparer<'Key> * System.Threading.CancellationToken -> System.Threading.Tasks.ValueTask<System.Linq.ILookup<'Key, 'Element>>

<Extension()>
Public Function ToLookupAsync(Of TSource, TKey, TElement) (source As IAsyncEnumerable(Of TSource), keySelector As Func(Of TSource, TKey), elementSelector As Func(Of TSource, TElement), Optional comparer As IEqualityComparer(Of TKey) = Nothing, Optional cancellationToken As CancellationToken = Nothing) As ValueTask(Of ILookup(Of TKey, TElement))

Type Parameters

TSource

The type of the elements of source.

TKey

The type of the key returned by keySelector.

TElement

The type of the value returned by elementSelector.

Parameters

source

IAsyncEnumerable<TSource>

The IAsyncEnumerable<T> to create a ILookup<TKey,TElement> from.

keySelector

Func<TSource,TKey>

A function to extract a key from each element.

elementSelector

Func<TSource,TElement>

A transform function to produce a result element value from each element.

comparer

IEqualityComparer<TKey>

An IEqualityComparer<T> to compare keys.

cancellationToken

CancellationToken

The CancellationToken to monitor for cancellation requests. The default is None.

Returns

ValueTask<ILookup<TKey,TElement>>

A ILookup<TKey,TElement> that contains keys and values.

Exceptions

ArgumentNullException

keySelector is null.

ToLookupAsync<TSource,TKey,TElement>(IAsyncEnumerable<TSource>, Func<TSource,CancellationToken,ValueTask<TKey>>, Func<TSource, CancellationToken,ValueTask<TElement>>, IEqualityComparer<TKey>, CancellationToken)

Source:

ToLookupAsync.cs

Creates a ILookup<TKey,TElement> from an IAsyncEnumerable<T> according to a specified key selector function and element selector functions.

public static System.Threading.Tasks.ValueTask<System.Linq.ILookup<TKey,TElement>> ToLookupAsync<TSource,TKey,TElement>(this System.Collections.Generic.IAsyncEnumerable<TSource> source, Func<TSource,System.Threading.CancellationToken,System.Threading.Tasks.ValueTask<TKey>> keySelector, Func<TSource,System.Threading.CancellationToken,System.Threading.Tasks.ValueTask<TElement>> elementSelector, System.Collections.Generic.IEqualityComparer<TKey>? comparer = default, System.Threading.CancellationToken cancellationToken = default);

static member ToLookupAsync : System.Collections.Generic.IAsyncEnumerable<'Source> * Func<'Source, System.Threading.CancellationToken, System.Threading.Tasks.ValueTask<'Key>> * Func<'Source, System.Threading.CancellationToken, System.Threading.Tasks.ValueTask<'Element>> * System.Collections.Generic.IEqualityComparer<'Key> * System.Threading.CancellationToken -> System.Threading.Tasks.ValueTask<System.Linq.ILookup<'Key, 'Element>>

<Extension()>
Public Function ToLookupAsync(Of TSource, TKey, TElement) (source As IAsyncEnumerable(Of TSource), keySelector As Func(Of TSource, CancellationToken, ValueTask(Of TKey)), elementSelector As Func(Of TSource, CancellationToken, ValueTask(Of TElement)), Optional comparer As IEqualityComparer(Of TKey) = Nothing, Optional cancellationToken As CancellationToken = Nothing) As ValueTask(Of ILookup(Of TKey, TElement))

Type Parameters

TSource

The type of the elements of source.

TKey

The type of the key returned by keySelector.

TElement

The type of the value returned by elementSelector.

Parameters

source

IAsyncEnumerable<TSource>

The IAsyncEnumerable<T> to create a ILookup<TKey,TElement> from.

keySelector

Func<TSource,CancellationToken,ValueTask<TKey>>

A function to extract a key from each element.

elementSelector

Func<TSource,CancellationToken,ValueTask<TElement>>

A transform function to produce a result element value from each element.

comparer

IEqualityComparer<TKey>

An IEqualityComparer<T> to compare keys.

cancellationToken

CancellationToken

The CancellationToken to monitor for cancellation requests. The default is None.

Returns

ValueTask<ILookup<TKey,TElement>>

A ILookup<TKey,TElement> that contains keys and values.

Exceptions

ArgumentNullException

keySelector is null.

ToLookupAsync<TSource,TKey>(IAsyncEnumerable<TSource>, Func<TSource,CancellationToken,ValueTask<TKey>>, IEqualityComparer<TKey>, CancellationToken)

Source:

ToLookupAsync.cs

Creates a ILookup<TKey,TElement> from an IAsyncEnumerable<T> according to a specified key selector function.

public static System.Threading.Tasks.ValueTask<System.Linq.ILookup<TKey,TSource>> ToLookupAsync<TSource,TKey>(this System.Collections.Generic.IAsyncEnumerable<TSource> source, Func<TSource,System.Threading.CancellationToken,System.Threading.Tasks.ValueTask<TKey>> keySelector, System.Collections.Generic.IEqualityComparer<TKey>? comparer = default, System.Threading.CancellationToken cancellationToken = default);

static member ToLookupAsync : System.Collections.Generic.IAsyncEnumerable<'Source> * Func<'Source, System.Threading.CancellationToken, System.Threading.Tasks.ValueTask<'Key>> * System.Collections.Generic.IEqualityComparer<'Key> * System.Threading.CancellationToken -> System.Threading.Tasks.ValueTask<System.Linq.ILookup<'Key, 'Source>>

<Extension()>
Public Function ToLookupAsync(Of TSource, TKey) (source As IAsyncEnumerable(Of TSource), keySelector As Func(Of TSource, CancellationToken, ValueTask(Of TKey)), Optional comparer As IEqualityComparer(Of TKey) = Nothing, Optional cancellationToken As CancellationToken = Nothing) As ValueTask(Of ILookup(Of TKey, TSource))

Type Parameters

TSource

The type of the elements of source.

TKey

The type of the key returned by keySelector.

Parameters

source

IAsyncEnumerable<TSource>

The IAsyncEnumerable<T> to create a ILookup<TKey,TElement> from.

keySelector

Func<TSource,CancellationToken,ValueTask<TKey>>

A function to extract a key from each element.

comparer

IEqualityComparer<TKey>

An IEqualityComparer<T> to compare keys.

cancellationToken

CancellationToken

The CancellationToken to monitor for cancellation requests. The default is None.

Returns

ValueTask<ILookup<TKey,TSource>>

A ILookup<TKey,TElement> that contains keys and values.

Exceptions

ArgumentNullException

keySelector is null.

ToLookupAsync<TSource,TKey>(IAsyncEnumerable<TSource>, Func<TSource,TKey>, IEqualityComparer<TKey>, CancellationToken)

Source:

ToLookupAsync.cs

Creates a ILookup<TKey,TElement> from an IAsyncEnumerable<T> according to a specified key selector function.

public static System.Threading.Tasks.ValueTask<System.Linq.ILookup<TKey,TSource>> ToLookupAsync<TSource,TKey>(this System.Collections.Generic.IAsyncEnumerable<TSource> source, Func<TSource,TKey> keySelector, System.Collections.Generic.IEqualityComparer<TKey>? comparer = default, System.Threading.CancellationToken cancellationToken = default);

static member ToLookupAsync : System.Collections.Generic.IAsyncEnumerable<'Source> * Func<'Source, 'Key> * System.Collections.Generic.IEqualityComparer<'Key> * System.Threading.CancellationToken -> System.Threading.Tasks.ValueTask<System.Linq.ILookup<'Key, 'Source>>

<Extension()>
Public Function ToLookupAsync(Of TSource, TKey) (source As IAsyncEnumerable(Of TSource), keySelector As Func(Of TSource, TKey), Optional comparer As IEqualityComparer(Of TKey) = Nothing, Optional cancellationToken As CancellationToken = Nothing) As ValueTask(Of ILookup(Of TKey, TSource))

Type Parameters

TSource

The type of the elements of source.

TKey

The type of the key returned by keySelector.

Parameters

source

IAsyncEnumerable<TSource>

The IAsyncEnumerable<T> to create a ILookup<TKey,TElement> from.

keySelector

Func<TSource,TKey>

A function to extract a key from each element.

comparer

IEqualityComparer<TKey>

An IEqualityComparer<T> to compare keys.

cancellationToken

CancellationToken

The CancellationToken to monitor for cancellation requests. The default is None.

Returns

ValueTask<ILookup<TKey,TSource>>

A ILookup<TKey,TElement> that contains keys and values.

Exceptions

ArgumentNullException

keySelector is null.