SHF: Small: Collaborative Research: Online Verification-Validation

Web上的现代软件越来越具有丰富的可扩展性，加速了其发展并大大缩短了开发和部署之间的时间。 这项研究的智力价值在于挑战在创建可扩展（易于重用和扩展）的软件和正确（满足其规范）的软件之间的错误选择。这项工作提出的新方法，增量验证，验证，使程序员能够将特定领域的安全学科可扩展的系统，通过提供一个框架，这些学科都是精确和有用的，作为可执行代码进行通信。 该项目更广泛的意义和重要性在于改变程序员为Web构建正确的可扩展软件的方法。该研究针对ECMAScript（JavaScript），使这项研究能够对创建和使用JavaScript的大量语言和系统产生直接影响。 此外，该项目代表了科罗拉多大学和马里兰州大学的新合作，汇集了验证，增量计算和运行时系统的专家。最后，这个项目有利于参与大学的研究生和本科生教学使命，因为项目的各个方面丰富了程序分析和编程语言courses.Incremental Verification-Validation鼓励程序员协同设计他们的系统与可执行规范，检查这些系统动态，因为他们执行。此外，与动态和非增量执行的典型断言不同，所提出的断言受到新模式的影响，从而提高了它们的性能：在回归验证中，验证部分地释放了一些检查，动态地用剩余版本重写程序;在渐进式验证中，在线验证发生在每个缓存和重用工作的通道中，以避免从零开始验证早期通行证仍然有效的事实。最后，为了避免迫使分析程序员在他们创建的每个分析中显式地推理增量变化，Meta层使用隐式增量元语言隐式地表达增量计算，该隐式增量元语言的抽象隐藏了基于每个变化的推理。

Increasingly, modern software on the web is richly extensible, accelerating its evolution and dramatically reducing the time between development and deployment. The intellectual merit of this research consists of challenging the false choice between creating software that is extensible (easy to reuse and extend) and software that is correct (meets its specifications). The new approach advanced by this work, Incremental Verification-Validation, enables programmers to bring domain-specific safely disciplines to extensible systems, by providing a framework where these disciplines are communicated both precisely and usefully, as executable code. The project's broader significance and importance consist in changing the way programmers approach building correct extensible software for the web. The research targets ECMAScript (JavaScript), enabling this research to have a direct impact on the vast number of languages and systems that create and use JavaScript. Further, the project represents a new collaboration across the University of Colorado and University of Maryland, bringing together experts across verification, incremental computing, and runtime systems. Finally, this project benefits the graduate and undergraduate teaching mission at the participating universities, as aspects of the project enriches the program analysis and programming language courses.Incremental Verification-Validation encourages programmers to co-design their systems with executable specifications that check these systems dynamically, as they execute. Moreover, unlike typical assertions, which execute dynamically and non-incrementally, the proposed are subject to novel patterns that enhance their performance: In regressive validation, verification partially discharges some checks, dynamically rewriting the program with residual versions; in progressive verification, online verification occurs in passes that each cache and reuse work, to avoid from-scratch verification of facts that still hold from earlier passes. Finally, to avoid forcing analysis programmers to reason about incremental changes explicitly in each analysis that they create, the meta layer expresses incremental computations implicitly, using an implicitly-incremental meta language whose abstractions hide reasoning on a per-change basis.