A Universe with Two Worlds

Matthias Felleisen

This universe teachpack implements and provides the functionality for creating interactive, graphical programs from plain functions. We refer to such programs as "world" programs. In addition, worlds can also become a part of a "universe".

The purpose of this documentation is to give experienced Schemers and HtDP teachers a concise overview for using the library. The first part of the documentation focuses on "worlds"; A First Sample World presents an illustration of "world construction" for an extremely simple domain and is suited for a novice who knows how to design conditional functions for symbols. The second half of the documentation focuses on "universes" that consist of two worlds. The very last section explains how to get two simple worlds to communicate with each other via a universe constructed with this teachpack.

Note: For a quick and educational introduction to just "worlds", see How to Design Programs, Second Edition: Prologue. As of August 2008, we also have a series of projects available as a small booklet on How to Design Worlds.