Algorithm Animation in a Declarative Visual Programming Language

How might capabilities for algorithm animation be seamlessly integrated into a programming language that is both visual and declarative? Until now, visual programming language researchers have not attempted to anwer that question, making the fruits of algorithm animation available only to users of textual programming languages. Users of visual programming languages (VPLs) have been deprived of the unique semantic insights algorithm animation offers, insights that would foster the understanding and debugging of visual programs. We have answered the question by seamlessly integrating algorithm animation capabilities into Forms/3, a general-purpose, declarative VPL. Our results show that such a VPL can support algorithm animation without leaving the declarative, visual model, without adding new concepts to the language or how to program in it, and without deviating from the uniform representation established for the language. In addition, our research shows that the characteristics of declarative VPLs result in some interesting algorithm animation features not found in other systems.