ObservableExtensions.

ConcatMap<TSource, TTaskResult, TResult>(IObservable<TSource>, Func<TSource, int, Task<TTaskResult>>, Func<TSource, int, TTaskResult, TResult>) Method

Summary

Projects each element of an observable sequence to a task by incorporating the element's index, invokes the result selector for the source element and the task result, and merges the results into one observable sequence.
Assembly
Rocket.Surgery.Reactive.Extensions.dll
Namespace
System.Reactive.Linq
Containing Type
ObservableExtensions

Syntax

public static IObservable<TResult> ConcatMap<TSource, TTaskResult, TResult>(this IObservable<TSource> source, Func<TSource, int, Task<TTaskResult>> taskSelector, Func<TSource, int, TTaskResult, TResult> resultSelector)

Type Parameters

Name Description
TSource The type of the elements in the source sequence.
TTaskResult The type of the results produced by the projected intermediate tasks.
TResult The type of the elements in the result sequence, obtained by using the selector to combine source sequence elements with their corresponding intermediate task results.

Parameters

Name Type Description
source IObservable<TSource> An observable sequence of elements to project.
taskSelector Func<TSource, int, Task<TTaskResult>> A transform function to apply to each element; the second parameter of the function represents the index of the source element.
resultSelector Func<TSource, int, TTaskResult, TResult> A transform function to apply to each element of the intermediate sequence; the second parameter of the function represents the index of the source element.

Return Value

Type Description
IObservable<TResult> An observable sequence whose elements are the result of obtaining a task for each element of the input sequence and then mapping the task's result and its corresponding source element to a result element.