SHF: Medium: Collaborative Research: Principled Optimizing Compilation of Dependently Typed Languages

题目：SHF：媒介：协作研究：独立类型语言的原则优化编译该项目侧重于一种带有程序验证的软件工程形式：用逻辑、机器可检查的正确性、可靠性或安全性证明编写程序。这种证明可以用传统编程语言编写的程序来完成，但是这些语言的“证明理论”是复杂和困难的，这使得验证既耗时又昂贵。新的“依赖类型”编程语言使用函数式编程和高级类型系统的原理来实现更流畅、更清晰的证明理论，因此验证（用这些新语言编写的）软件的正确性和安全性要容易得多。在这个项目中，研究的是为这些新语言构建高效且被验证正确的编译器。智力上的优点在于在依赖类型的纯功能上下文中出现的挑战和机遇，例如Coq证明助手。只有在这种情况下才会出现令人兴奋的机会，即能够为任何子术语选择求值顺序（因为Coq的语言是纯粹和全面的），能够为用户指定的（和认证的）重写规则打开编译器，支持特定于应用程序的优化，以及程序员能够使用Coq的归纳构造演算（CiC）证明理论来验证他们的程序。我们所面临的挑战，在这种情况下是独一无二的，包括需要确定和删除那些计算上不相关的术语。一个主要的基础挑战是在执行降低转换（例如转换为延续传递样式（CPS）或静态单赋值（SSA））时，试图保留类型（以及证明）。我们的策略是在可能的情况下使用类型和证明保留编译，而在不可能的情况下使用类型和证明保留编译来证明基于模拟的正确性概念。更广泛的影响将包括(1)Coq中经过验证的函数式编程的教学材料；(2)培养研究生；(3)在软件工程实践中的改进，使实际验证的函数式编程成为可能。

Title: SHF: Medium: Collaborative Research: Principled Optimizing Compilation of Dependently Typed LanguagesThe project focuses on a form of software engineering with program verification: writing programs with logical, machine-checkable proofs of correctness, reliability, or security. Such proofs can be done for programs written in conventional programming languages, but the "proof theory" of these languages is complex and difficult, which makes verification time-consuming and expensive. New, "dependently typed" programming languages use principles of functional programming and advanced type systems to achieve a smoother and cleaner proof theory, so that verifying the correctness and safety of software (written in these new languages) is much easier. In this project, the research is to build compilers for these new languages that are efficient and are verified correct.The intellectual merits are in the challenges and opportunities that occur in dependently typed, purely functional contexts, such as the Coq proof assistant. The exciting opportunities that arise only in this context are the ability to choose evaluation order for any sub-term (since Coq's language is pure and total), the ability to open a compiler to user-specified (and certified) rewrite rules that support application-specific optimization, and the ability of programmers to use the Calculus of Inductive Constructions (CiC) proof theory of Coq to verify their programs. The challenges we face, unique to this setting, include the need to determine and erase those terms that are computationally irrelevant. A major foundational challenge is attempting to preserve types (and hence proofs) as we perform lowering transformations, such as conversion to continuation-passing style (CPS) or static single assignment (SSA). Our strategy is to use type and proof-preserving compilation where possible, and where not, to prove a simulation-based notion of correctness. The broader impacts will include (1) pedagogical materials on verified functional programming in Coq; (2) training of graduate students; and (3) improvements in software engineering practice, in enabling practical verified functional programming.