Using Scheme in 6.001

 

In previous terms, we have used versions of MIT Scheme for programming in 6.001. While this has many advantages, because it is a home-grown system it does not include some of the more standard user interface tools of more commonly supported options. As an experiment, a few terms ago, we shifted to use DrScheme.

A Note About DrScheme

DrScheme is The Programming Languages Team's graphical user interface to a Scheme system for students. As noted, we have been experimenting with using DrScheme, in part because of the features noted below, and in part because DrScheme is free. To download DrScheme onto your machine, simply click on the link to DrScheme at the beginning of this paragraph and follow the instructions.

DrScheme has some innovative user-interface features not found in MIT Scheme: text is color-coded, for example to highlight (in red) undefined variables; it has a syntax analysis command which, for example, can display arrows from occurrences of variables to their definitions elsewhere in the code; it has several output modes in addition to the standard one, for example an output mode which shows sharing in lists, and another output mode in which values are printed as canonical INPUT expressions -- in this mode, for example, the list value which is the result of evaluating (cons 1 (cons (+ 2 3) '())) prints out as (list 1 5). DrScheme also has Windows menu control of most features, and error messages that are more clear than those in MIT Scheme.

To run satisfactorily, it requires at least 20MB of RAM and a 150MHZ processor. System documentation for DrScheme is available as part of the download.

If you have a PC capable of running Scheme, we suggest that you install DrScheme on it, since it will be convenient for you to work at home a lot of the time. You should feel free to use the lab, in addition, at any time -- because you would like help from the Lab Assistants, or because you want to work in a room with your fellow students. But you should realize that the lab is often very crowded just before projects are due. Feel free to do assignments partially in the 6.001 Lab, where you can work with the Lab Assistants, and partially on your own machine. You can also save your work in progress on a memory stick or in an Athena locker, come to the 6.001 lab, and get help from the lab assistants based on your work.

 

 

MIT Scheme Options

While we are going to experiment with DrScheme this term, the following systems are also available for use:

All these implementations (including editor, debugger, etc.) are virtually identical.

 

Other Unsupported Options

There are several other versions of Scheme available, either for free or for a small fee:

EdScheme from Schemers, Inc.

Any Scheme system you find on Windows 3.1.

Any Scheme system you find on Windows 98 or Windows ME.

Feel free to try these out, but bear in mind that:

         The projects are not tested on these systems, and may not work on them.

         If you need help from the staff, you must be prepared to copy all the files you are using to an Athena locker and reproduce the problem in the 6.001 lab using the supported system.

         The staff will not grant extensions or waivers on problem sets that can't be done in these systems.  You have been warned.


 

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