AgentSkillsCN

Swift Error Handling

抛出式函数、Result 类型与 Never 类型的规范

SKILL.md
--- frontmatter
name: Swift Error Handling
description: Standards for Throwing Functions, Result Type, and Never
metadata:
  labels: [swift, errors, throws, result]
  triggers:
    files: ['**/*.swift']
    keywords: ['throws', 'try', 'catch', 'Result', 'Error']

Swift Error Handling

Priority: P0

Implementation Guidelines

Throwing Functions

  • •Propagate Errors: Use throws for recoverable errors.
  • •Do-Catch: Handle errors close to source with specific catch blocks.
  • •Error Types: Define custom errors as enums conforming to Error.

Result Type

  • •Async Alternatives: Use Result<Success, Failure> for callback-based APIs.
  • •Transformations: Use .map(), .flatMap() for functional composition.
  • •Conversion: Use .get() to convert Result to throwing.

Never Type

  • •Fatalisms: Use Never return type for functions that never return.
  • •Preconditions: fatalError(), preconditionFailure() for programmer errors.

Anti-Patterns

  • •Force Try: **No try!**: Use try? or do-catch.
  • •Silent Failures: **No try? without nil check**: Handle or log.
  • •String Errors: **No Error(message)**: Use typed errors.

References