ChooseExtensionChooseT, TResult Method

Applies a function to each element of the source sequence and returns a new sequence of result elements for source elements where the function returns a couple (2-tuple) having a true as its first element and result as the second.

Namespace: MoreLinq.Extensions
Assembly: MoreLinq (in MoreLinq.dll) Version: 3.2.0+5205ea241d72b079436060d330cd5c2eae7cdcdf

Syntax

C++

Copy

public static IEnumerable<TResult> Choose<T, TResult>(
	this IEnumerable<T> source,
	Func<T, (bool , TResult , )> chooser
)

<ExtensionAttribute>
Public Shared Function Choose(Of T, TResult) ( 
	source As IEnumerable(Of T),
	chooser As Func(Of T, ( As Boolean,  As TResult, ))
) As IEnumerable(Of TResult)

public:
[ExtensionAttribute]
generic<typename T, typename TResult>
static IEnumerable<TResult>^ Choose(
	IEnumerable<T>^ source, 
	Func<T, ValueTuple<bool, TResult>>^ chooser
)

[<ExtensionAttribute>]
static member Choose : 
        source : IEnumerable<'T> * 
        chooser : Func<'T, ValueTuple<bool, 'TResult>> -> IEnumerable<'TResult>

Parameters

source: Type: System.Collections.GenericIEnumerableT
The source sequence.
chooser: Type: SystemFuncT, ValueTupleBoolean, TResult
The function that is applied to each source element.

Type Parameters

T: The type of the elements in source.
TResult: The type of the elements in the returned sequence.

Return Value

Type: IEnumerableTResult
A sequence TResult elements.

Usage Note

In Visual Basic and C#, you can call this method as an instance method on any object of type IEnumerableT. When you use instance method syntax to call this method, omit the first parameter. For more information, see Extension Methods (Visual Basic) or Extension Methods (C# Programming Guide).

Remarks

This method uses deferred execution semantics and streams its results.

Examples

Copy

var str = "O,l,2,3,4,S,6,7,B,9";
var xs = str.Split(',').Choose(s => (int.TryParse(s, out var n), n));

The xs variable will be a sequence of the integers 2, 3, 4, 6, 7 and 9.

Reference

ChooseExtension Class