SWAN: A Data Structure Visualization System

Swan is a data structure visualization system. It allows users to visualize the data structures and execution process of a C/C++ program. Swan views a data structure as a graph or collection of graphs. By “graph” we mean general directed and undirected graphs and special cases such as trees, lists and arrays. As a part of Virginia Tech’s NSF Educational Infrastructure Grant, Swan will be used in two ways: by instructors as a teaching tool for data structures and algorithms, and by students visualizing their own programs to understand how and why they do or do not work. To use Swan, a program must first be annotated, i.e., Swan calls are added to an existing program. The program is then compiled and linked with the Swan Annotation Interface Library (SAIL). The viewer then runs the annotated program. Many program visualization systems exist. See [5, 4] for examples. These have been used for teaching, presentation, and debugging purposes. The main design goal for Swan was to create an easy-to-use annotation library combined with a simple, yet powerful, user interface for the resulting visualization. Several features distinguish Swan from most other program visualization systems: