IAsyncEnumerable.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;

class Program
{
    static async Task Main()
    {
        IAsyncEnumerable<int> numbers = GetNumbersAsync();

        Func<int, Task<int>> asyncDoubleNumber = async n =>
        {
            await Task.Delay(10); // Simulate some async work
            return n * 2;
        };

        IAsyncEnumerable<int> transformedNumbers = StreamAndTransformAsync(numbers, asyncDoubleNumber);


        await foreach (var number in transformedNumbers)
        {
            Console.WriteLine(number);
        }
    }

    // Asynchronous data source simulation
    static async IAsyncEnumerable<int> GetNumbersAsync()
    {
        for (int i = 1; i <= 100; i++)
        {
            await Task.Delay(5); // Simulate async data retrieval
            yield return i;
        }
    }

  
    static async IAsyncEnumerable<T> StreamAndTransformAsync<T>(IAsyncEnumerable<T> source, Func<T, Task<T>> transformation)
    {
        await foreach (var item in source)
        {
            yield return await transformation(item);
        }
    }
}