ciel-swift-and-ios-standards

CIEL ADAPTATION: Swift & iOS Standards (The Apple Layer)

This skill formalizes modern Swift development. it prioritizes data-race safety and the Liquid Glass design language.

Approachable Concurrency (Swift 6.2+)

1. Single-Threaded Default: Start on MainActor. Async functions stay on the calling actor by default.
2. Isolated Conformances: Conforming MainActor types to protocols safely without @Sendable workarounds.
3. Explicit Parallelism: Use @concurrent ONLY for CPU-intensive background tasks (e.g., image processing).
4. Static State: Protect all global/static variables with MainActor or actor isolation.

Actor-Based Persistence

• Repository: Use actor for serialized access to local data.
• In-Memory Cache: Maintain a dictionary for O(1) lookups; persist to disk atomically on write.
• Hard Gate: ALWAYS use .atomic writes to prevent file corruption.
• Initialization: Load cache synchronously in init to avoid async lifecycle complexity.

Liquid Glass Design (iOS 26+)

• Container First: Wrap multiple glass elements in a GlassEffectContainer for performance and morphing.
• Interactivity: Use .interactive() only on touch/pointer targets.
• Transitions: Use @Namespace + glassEffectID for smooth morphing on view hierarchy changes.

Anti-Patterns

• Implicit Offloading: Assuming async functions run in the background (they stay on the caller in 6.2).
• DispatchQueue Overuse: Using legacy queues instead of actors for new thread-safe state.
• Opaque Glass: Placing opaque backgrounds behind glass elements (destroys the translucency effect).