AgentSkillsCN

Swift Language

Optional、协议、扩展与类型安全的规范

SKILL.md
--- frontmatter
name: Swift Language
description: Standards for Optionals, Protocols, Extensions, and Type Safety
metadata:
  labels: [swift, language, optionals, protocols]
  triggers:
    files: ['**/*.swift']
    keywords: ['protocol', 'extension', 'optional', 'guard', 'enum']

Swift Language Standards

Priority: P0

Implementation Guidelines

Optionals & Safety

  • •Never Force Unwrap: Use guard let, if let, or nil coalescing (??).
  • •Nil Comparison: Use value != nil instead of if let _ = value.
  • •Implicitly Unwrapped: Avoid Type!. Use proper Type?.

Protocols & Extensions

  • •Protocol Composition: Prefer struct + protocols over class inheritance.
  • •Extensions: Use for conformance (extension MyType: Codable), not storage.
  • •Protocol Witnesses: Explicitly implement all required members.

Type Safety

  • •Avoid Any: Use generics or associated types instead.
  • •Enums: Prefer enums with associated values over multiple Optionals.
  • •Value Types: Default to struct unless reference semantics needed.

Anti-Patterns

  • •Force Unwrapping: **No ! operator**: Use safe unwrapping.
  • •Sentinel Values: **No -1 for failure**: Use Optional.
  • •as! Casting: **No Force Cast**: Use conditional cast (as?).

References