Trellis: turning designs into programs

When designing an object-oriented program, there are several goals to achieve: The program should accurately model the real-world objects to be represented. This leads to a program that is easier to understand and therefore simpler to maintain. Code that implements the model accurately must also be robust. Inconsistent models should be detected at design time, not diagnosed as a run-time error at a customer's installation. The programming environment must allow for convenient exploration of the application; it should foster a reuse of existing types of objects, thus reducing the scale of the design. It should also facilitate changes to the program as the application design is updated. The Trellis programming system is an integrated language and environment that provides many of the mechanisms needed to design and implement object-oriented programs. The remainder of this sidebar discusses how Trellis helps attain the goals outlined above.