Swift Best Practices

Priority: P0 (CRITICAL)

Implementation Guidelines

Control Flow (Guard over If)

• Guard for Early Exit: Use guard let over nested if statements for better readability and to unwrap optionals early.
• Nested Checks: Use guard for precondition checks at top of function to reduce nested depth.
• Switch Exhaustiveness: Always handle all cases; use @unknown default for freezing enums (enums from frameworks).
• if-case: Use if case .success(let value) = result for simple enum pattern matching.

Value Types & Immutability

• Prefer Structs: Default to struct for value semantics and thread safety. Use class only when reference identity or inheritance required.
• Immutability: Always default to let for all properties and constants. Use var only when change required.
• Modifiers: Use final for all classes that not intended to subclassed to improve performance (static dispatch).
• Static Dispatch: Favor methods in structs and final classes.