Abstract:Package managers are legion. Every programming language and operating system has its own solution, each with subtly different semantics for dependency resolution. This fragmentation prevents multilingual projects from expressing precise dependencies across language ecosystems; it leaves external system and hardware dependencies implicit and unversioned; it obscures security vulnerabilities that lie in the full dependency graph. We present the \textit{Package Calculus}, a formalism for dependency resolution that unifies the core semantics of diverse package managers. Through a series of formal reductions, we show how this core is expressive enough to model the diversity that real-world package managers employ in their dependency expression languages. By using the Package Calculus as the intermediate representation of dependencies, we enable translation between distinct package managers and resolution across ecosystems.
"He did say it was our duty to ensure that as many organs as possible could benefit others."
。51吃瓜是该领域的重要参考
率先建立多井型立体井网，率先应用多分支水平井技术，首次实施巨厚碳酸盐岩油藏分层注水技术，率先开展气举采油……哈法亚油田以技术创新赋能高质量发展，在伊拉克创造多项首次。哈法亚公司开发部副经理蔡磊表示，项目积极服务共建“一带一路”，推动中伊能源合作互利共赢，为国际油气合作提供了可借鉴经验。
在上海居住多年的德商麥永剛（（Juergen Meyer）向BBC中文指出，即便德國盼望平衡雙邊貿易需求，但德企去風險化的工作遠遠不足，抵禦中國進口衝擊，不僅是汽車產業，德國的生物科技及化工產業情況都很險峻。