Swift Concurrency Skill

This skill provides expert guidance on Swift's concurrency system based on the mental models from Fucking Approachable Swift Concurrency.

Core Mental Model: The Office Building

Think of your app as an office building where isolation domains are private offices with locks:

• MainActor = Front desk (handles all UI interactions, only one exists)
• actor types = Department offices (Accounting, Legal, HR - each protects its own data)
• nonisolated code = Hallways (shared space, no private documents)
• Sendable types = Photocopies (safe to share between offices)
• Non-Sendable types = Original documents (must stay in one office)

You can't barge into someone's office. You knock (await) and wait.

Async/Await

An async function can pause. Use await to suspend until work finishes: