Visual Programming

ion One of the challenges in visual programming research is scaling up to the support of ever-larger programs. This is a greater issue for VPLs than for traditional textual languages (although it certainly can be said to exist in both) for reasons relating to representation, language design and implementation, and relative youth of the area. For example, some of the visual mechanisms used to achieve characteristics such as explicitness can occupy a great deal of space, making it harder to maintain context. Also, it is hard to apply in a straightforward way techniques developed for traditional languages, because doing so often results in a reintroduction of the very complexities VPLs have tried to remove or simplify. Recent developments in the area of abstraction have been particularly important to the scalability of VPLs. The two most widely-supported types of abstraction, both in visual and textual languages, are procedural abstraction and data abstraction. In particular, procedural ..