swift-approachable-concurrency

Migrate Swift projects to strict concurrency by applying incremental isolation rules using MainActor and actors. This Skill provides real-world migration examples to safely transition codebases from Swift 5 to Swift 6.

MainActor isolation confines execution to the main thread for UI safety. Use it to protect UI-bound state, while actors and nonisolated handle background domains to ensure safe concurrent execution.

Common Swift concurrency pitfalls involve crossing isolation domains with non-Sendable types and unstructured Task usage. Apply safe concurrency patterns to validate isolation boundaries and prevent data races.

Async/await serializes access to actor-isolated state, enforcing safe concurrency. Combining structured concurrency with actors creates safe execution paths across UI and background work in Swift 6.2.

Use nonisolated functions to execute code outside MainActor isolation domains. This pattern suits stateless operations, ensuring safe concurrency without blocking the main thread in Swift 6.

Model isolation domains by defining boundaries using MainActor for UI, actors for shared state, and nonisolated for independent logic. This establishes clear mental models for safe concurrent execution.