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# AsyncStream.Continuation

A mechanism to interface between synchronous code and an asynchronous
stream.

```
struct Continuation
```

## Overview

The closure you provide to the `AsyncStream` in
`init(_:bufferingPolicy:_:)` receives an instance of this type when
invoked. Use this continuation to provide elements to the stream by
calling one of the `yield` methods, then terminate the stream normally by
calling the `finish()` method.

> Note: Unlike other continuations in Swift, `AsyncStream.Continuation`
> supports escaping.

## Topics

### Producing Elements

[`yield(_:)`](/documentation/Swift/AsyncStream/Continuation/yield(_:))

Resume the task awaiting the next iteration point by having it return
normally from its suspension point with a given element.

[`yield(with:)`](/documentation/Swift/AsyncStream/Continuation/yield(with:))

Resume the task awaiting the next iteration point by having it return
normally from its suspension point with a given result’s success value.

[`yield()`](/documentation/Swift/AsyncStream/Continuation/yield())

Resume the task awaiting the next iteration point by having it return
normally from its suspension point.

[`AsyncStream.Continuation.YieldResult`](/documentation/Swift/AsyncStream/Continuation/YieldResult)

A type that indicates the result of yielding a value to a client, by
way of the continuation.

### Finishing the Stream

[`finish()`](/documentation/Swift/AsyncStream/Continuation/finish())

Resume the task awaiting the next iteration point by having it return
nil, which signifies the end of the iteration.

### Handling Termination

[`onTermination`](/documentation/Swift/AsyncStream/Continuation/onTermination)

A callback to invoke when canceling iteration of an asynchronous
stream.

[`AsyncStream.Continuation.Termination`](/documentation/Swift/AsyncStream/Continuation/Termination)

A type that indicates how the stream terminated.


---

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