Swift 6 LLM Primer

README.md

Swift 6 LLM Primer

Generated by ChatGPT for use with LLMs which have not yet been trained on Swift 6.

Swift6.md

Swift 6 LLM Primer

This file provides a set of Swift 6 idioms and conventions to prime a large language model (LLM) for generating Swift 6–compliant code. Include this markdown in the prompt context before your actual request.

---

📦 Strict Concurrency and Sendable

// Assume the following strict concurrency settings:
/// - SWIFT_VERSION = 6.0
/// - SWIFT_STRICT_CONCURRENCY = complete

// Always use Swift Concurrency.
// Avoid DispatchQueue or Combine.
// All types should conform to Sendable where applicable.

---

🧠 Swift 6 Build Configuration

// Swift 6 build configuration is assumed:
/// - Enable strict concurrency
/// - All warnings are treated as errors
/// - Use value types and actor isolation to avoid data races

---

👁️ Observation with @Observable

// Use the new Observation system in SwiftUI:
@Observable
class Library {
  var books: [Book] = []
}

// Avoid using @Published or ObservableObject.
// Use @Bindable in views when editing observable properties.
// Use @Environment(Library.self) and @State for injecting and storing models.

---

🧪 Swift 6 Testing Framework

// Use the new Swift Testing framework with @Test and #expect:
import Testing

struct MathTests {
  @Test
  func testSum() {
    let result = 2 + 2
    #expect(result == 4)
  }
}

---

⛓️ Structured Concurrency Idioms

// Prefer structured concurrency:
async let a = loadDataA()
async let b = loadDataB()
let result = await (try await a, try await b)

// For dynamic concurrency, use withTaskGroup

---

🔒 Actor Isolation

actor Counter {
  private var count = 0

  func increment() {
    count += 1
  }

  func value() -> Int {
    count
  }
}

---

🧰 Avoiding Common Anti-Patterns

// Avoid:
// - ObservableObject + @Published (use @Observable instead)
// - DispatchQueue or Combine (use async/await and actors)
// - Using AnyView to erase types (prefer opaque return types using `some View`)
// - Storing state in the Environment unnecessarily