mainactor

The concept of MainActor is discussed in the session titled "Migrate your app to Swift 6". Here are some key points from the session:

1. Non-Isolated Methods: You can declare a method as non-isolated to the main actor, which means it won't be isolated to the main actor despite being on a main actor isolated type. This is useful for callbacks that don't guarantee where they call you back from. However, if you need to work on the main actor, you might need to start a task on the main actor (Migrate your app to Swift 6).

2. Assume Isolated: If you know a method is called on the main actor, you can use assume isolated to tell the compiler that the code is already running on the main actor. This avoids starting a new task to async onto the main actor (Migrate your app to Swift 6).

3. Implicit Asynchronous Calls: Calls to actor-isolated state are implicitly asynchronous. If a function isn't asynchronous, you need to mark it as async or start a new task. The compiler can offer a fix to put the function on the main actor (Migrate your app to Swift 6).

4. Protocol Conformance: Many delegates and protocols, like SwiftUI views, are designed to operate only on the main actor and have been annotated accordingly. This ensures they are only called on the main actor (Migrate your app to Swift 6).

Relevant Sessions

• Migrate your app to Swift 6
• A Swift Tour: Explore Swift’s features and design

These sessions provide a comprehensive overview of how to work with MainActor in Swift 6, including practical examples and migration strategies.