ParallelEnumerable.GroupBy<'TSource, 'TKey, 'TResult> Method (ParallelQuery<'TSource>, Func<'TSource, 'TKey>, Func<'TKey, IEnumerable<'TSource>, 'TResult>)
Groups in parallel the elements of a sequence according to a specified key selector function and creates a result value from each group and its key.
Assembly: System.Core (in System.Core.dll)
static member GroupBy<'TSource, 'TKey, 'TResult> : source:ParallelQuery<'TSource> * keySelector:Func<'TSource, 'TKey> * resultSelector:Func<'TKey, IEnumerable<'TSource>, 'TResult> -> ParallelQuery<'TResult>
A sequence whose elements to group.
A function to extract the key for each element.
Return ValueType: System.Linq.ParallelQuery<'TResult>
A sequence of elements of type TResult where each element represents a projection over a group and its key.
The type of the elements of source.
The type of the key returned by keySelector.
The type of the result value returned by resultSelector.
Available since 4.5
Available since 4.0
Portable Class Library
Supported in: portable .NET platforms
Available since 8.1