SHF: Medium: Collaborative Research: FRP for Real

功能性反应性编程（FRP）是一种基于两个基本抽象的声明性编程范式：时变行为的连续（功能）建模，以及用户和进程交互的离散（反应性）演算。FRP提供了一种新颖而有效的方法来解决诸如计算机动画、机器人、控制系统、图形用户界面和交互式多媒体中存在的连续和离散实体组合的问题。FRP的广泛影响体现在其他几个研究项目的采用，以及它在不同于耶鲁大学的几个应用中的应用。拟议的工作将加强这些现有项目，并进一步扩大FRP的适用性。在实施方面提出的改进将使FRP更适合于计算密集型应用，例如交互式3D图形和实时音频处理。它还将有利于建模和仿真社区，他们经常使用声明性方法来指定和解决问题。耶鲁大学以前的研究帮助建立了FRP的基础，并证明了它在几个应用领域的效用。尽管取得了初步的成功，但要使“FRP成为现实”，还需要做更多的工作。也就是说，开发一个系统，方便编写自然和简洁的反应性行为描述，响应足够好，以满足大多数常见的实时约束，将现实世界的对象具体化为一级信号函数，通过程序优化和多核架构上的并行执行高效运行，并已在现实世界的应用领域中得到验证，特别是音频信号处理。建议的研究将在三个方面推进整体FRP方法：语言设计（类型系统扩展以捕获资源约束，重新设计离散和连续之间的中介，以及更好的语法以捕获FRP的本质）；语言实现（程序优化、多核执行、异步子进程）；验证和测试（重点是实时音频信号处理）。

Functional Reactive Programming, or FRP, is a declarative programming paradigm based on two fundamental abstractions: a continuous (functional) modeling of time-varying behaviors, and a discrete (reactive) calculus of user and process interaction. FRP provides a novel and effective approach to solving problems in which there is a combination of both continuous and discrete entities such as found in computer animation, robotics, control systems, GUIs, and interactive multimedia. FRP's broader impact is seen in its adoption by several other research projects, and its use in several applications different from those at Yale. The proposed work will strengthen these existing projects, and further broaden the applicability of FRP. The proposed improvements in implementation will make FRP more suitable for compute-intensive applications, such as interactive 3D graphics and real-time audio processing. It will also benefit the modeling and simulation community, which often uses declarative approaches to specifying and solving problems. Previous research at Yale helped to establish the foundations of FRP, and demonstrated its utility in several application domains. Despite this preliminary success, more work is needed to make "FRP for real." That is, to develop a system that facilitates writing natural and concise descriptions of reactive behaviors, responds well enough to satisfy most common real-time constraints, reifies real-world objects as first-class signal functions, runs efficiently through program optimization and parallel execution on multicore architectures, and has been validated in a real-world application domain, specifically audio signal processing. The proposed research will advance the overall FRP methodology in three areas: Language Design (type system extensions to capture resource constraints, a redesign of the mediation between the discrete and continuous, and a better syntax to capture the essence of FRP); Language Implementation (program optimizations, multicore execution, asynchronous sub-processes); and Validation and Testing (with a focus on real-time audio signal processing).