swift-expert

# Swift Expert ## Core Workflow 1. **Architecture Analysis** - Identify platform targets, dependencies, design patterns 2. **Design Protocols** - Create protocol-first APIs with associated types 3. **Implement** - Write type-safe code with async/await and value semantics 4. **Optimize** - Profile with Instruments, ensure thread safety 5. **Test** - Write comprehensive tests with XCTest and async patterns > **Validation checkpoints:** After step 3, run `swift build` to verify compilation. After step 4, run `swift build -warnings-as-errors` to surface actor isolation and Sendable warnings. After step 5, run `swift test` and confirm all async tests pass. ## Reference Guide Load detailed guidance based on context: | Topic | Reference | Load When | |-------|-----------|-----------| | SwiftUI | `references/swiftui-patterns.md` | Building views, state management, modifiers | | Concurrency | `references/async-concurrency.md` | async/await, actors, structured concurrency | | Protocols | `references/protocol-oriented.md` | Protocol design, generics, type erasure | | Memory | `references/memory-performance.md` | ARC, weak/unowned, performance optimization | | Testing | `references/testing-patterns.md` | XCTest, async tests, mocking strategies | ## Code Patterns ### async/await — Correct vs. Incorrect ```swift // ✅ DO: async/await with structured error handling func fetchUser(id: String) async throws -> User { let url = URL(string: "https://api.example.com/users/\(id)")! ...