NYI: Visual Programming Languages (Scaling Up)

可视化编程在直觉上非常吸引人，因为它允许程序员简单地通过勾勒、指向或演示数据来表达数据之间的关系或对数据的转换--而不是通过将它们转换为命令、指针和抽象符号的序列。这消除了许多传统上编程计算机所需的概念，再加上持续的视觉反馈，提供了使编程更容易和更可靠的前景。然而，有一个问题导致视觉编程的潜力在很大程度上仍未得到开发。到目前为止，大多数可视化编程语言(VPL)都不能很容易地扩展到小型演示程序之外，以便在不重新引入它们试图删除的概念的情况下充分处理实际编程。这个问题被称为放大问题。本研究的目的是为了提高VPLS的可扩展性。重点放在三个方面：(1)开发方法来提高表达能力和代码重用性，同时保持简单和具体的性质；(2)开发适合于VPL的隐式多态类型的具体方法；以及(3)扩展VPL的适用性。这三个方向的研究成果在研究系统Forms/3中得到了原型，Forms/3是一种懒惰的说明性可视化语言。

Visual programming is intuitively very appealing, because it allows the programmer to express relationships among, or transformations to, data simply by sketching them, pointing at them, or demonstrating them -- not by translating them into sequences of commands, pointers, and abstract symbols. This removal of many of the concepts traditionally required to program computers, combined with continuous visual feedback, offers the promise of making programming easier and more reliable. Yet, there is a problem that has caused the potential of visual programming to remain largely untapped. Most visual programming languages (VPLs) to date are not easily extended beyond small demonstration programs to adequately handle realistic programming without re-introducing the very concepts they have tried to remove. This problem is called the scaling-up problem. The objective of this research is to improve the scalability of VPLs. The focus is in three directions: (1) developing ways to increase expressive power and code reuse that also maintain the qualities of simplicity and concreteness; (2) developing a concrete approach to implicit polymorphic types suitable for VPLs; and (3) extending the applicability of VPLs. Research results from investigating these three directions are prototyped in the research system Forms/3, a lazy declarative visual language.