This chapter covers
- Using
Taskto represent asynchronous computations
- Composing asynchronous operations sequentially and in parallel
- Working with asynchronous sequences
In today’s world of distributed applications, many operations are performed asynchronously. A program may begin some operation that takes a relatively long time, such as requesting data from another application, but it won’t sit idle, waiting for that operation to complete. Instead, it will go on to do other work and resume the operation once the data has been received.
Asynchrony certainly is the bread and butter of today’s programmer. I waited until this late in the book to deal with it because it adds a level of complexity, which I wanted to postpone in order to make the ideas presented so far more approachable.
Asynchronous operations are represented in C# using Task, and in this chapter you’ll see that Task<T> is not so different from other containers, such as Option<T>, Try<T>, and so on. While Task<T> represents a single value that is delivered asynchronously, IAsyncEnumerable<T> is a recent addition to the language that is used to represent a sequence of values that are delivered asynchronously; I’ll discuss this in the second part of this chapter.