Realistic Program Visualization in CafePie

CafePie is a visual programming environment for CafeOBJ, an algebraic specification language based on term rewriting. CafePie shows term rewriting directly by using two types of visualizations: animated cartoon-like and Obi-shaped. A more abstract visualization schema is necessary instead of program understanding at the programming language level. Therefore we investigate the visualization schema, which uses more realistic expressions. Here we visualize term rewriting with more realistic expressions by using figures, pictures and images. In CafeOBJ, rewriting rules are called “equations.” An equation is composed of operators and variables. We map operators to realistic expressions so that equations are expressed as transformations of realistic expressions. We use visual transformation rules which give the program pictorial expressions.