Uniformity of environment and computation in MAP

Visual programming languages use graphics to visualize and aid in the understanding of programs. We describe the graphical techniques used in the MAP environment to visualize the workspace, data, programs and program executions. Meta information is one approach to supplementing the basic functionality provided in the visual programming environment. We introduce meta-commands, commands to control visual characteristics of program objects, and describe the MAP meta-commands for color, folding, render and transparency. We show how these meta-commands can be used to affect graphical representation of programs and their executions and as a way to optimize the recording of program executions, and present examples of how a programmer can use these techniques to build, execute and analyze programs.