67 lines
1.5 KiB
Markdown
67 lines
1.5 KiB
Markdown
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---
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paths:
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- "**/*.swift"
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- "**/Package.swift"
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---
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# Swift Patterns
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> This file extends [common/patterns.md](../common/patterns.md) with Swift specific content.
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## Protocol-Oriented Design
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Define small, focused protocols. Use protocol extensions for shared defaults:
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```swift
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protocol Repository: Sendable {
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associatedtype Item: Identifiable & Sendable
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func find(by id: Item.ID) async throws -> Item?
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func save(_ item: Item) async throws
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}
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```
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## Value Types
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- Use structs for data transfer objects and models
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- Use enums with associated values to model distinct states:
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```swift
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enum LoadState<T: Sendable>: Sendable {
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case idle
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case loading
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case loaded(T)
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case failed(Error)
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}
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```
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## Actor Pattern
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Use actors for shared mutable state instead of locks or dispatch queues:
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```swift
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actor Cache<Key: Hashable & Sendable, Value: Sendable> {
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private var storage: [Key: Value] = [:]
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func get(_ key: Key) -> Value? { storage[key] }
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func set(_ key: Key, value: Value) { storage[key] = value }
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}
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```
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## Dependency Injection
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Inject protocols with default parameters — production uses defaults, tests inject mocks:
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```swift
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struct UserService {
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private let repository: any UserRepository
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init(repository: any UserRepository = DefaultUserRepository()) {
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self.repository = repository
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}
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}
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```
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## References
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See skill: `swift-actor-persistence` for actor-based persistence patterns.
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See skill: `swift-protocol-di-testing` for protocol-based DI and testing.
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