Add `--empty` flag

描述

贡献者指南

技术栈

swiftshell

领域

cli

议题类型

feature

难度面向新贡献者的预计实现难度，1 表示很小改动，5 表示专家级工作。

3

预计时间有经验贡献者完成调查、实现、测试并准备 pull request 的粗略时间范围。

1-3 hours

活动状态议题当前的可参与程度：新鲜、活跃、陈旧、阻塞或等待维护者输入。

active

清晰度议题是否清楚说明期望改动、验收标准和下一步。

mostly clear

前置要求

Swift basicscommand line tool structure

新手友好度1-100 的估计分数，表示该议题对首次贡献者的友好程度。

60

研究方向

Examine the current command line interface implementation in the repository, likely in main.swift or equivalent. Look for how existing flags like list or clear are handled (though they may not exist yet). Review the comments in issue #28 to see if maintainers have provided any guidance on implementation approach or preferred flag syntax. Consider using a Swift argument parser library such as ArgumentParser. The two flags list and clear should be implemented separately but in the same commit if the issue is combined. Ensure proper error handling and documentation.