Using Concrete Abstractions with MIT-Scheme
This web page provides information regarding the use of the MIT-Scheme
implementation of Scheme with Concrete Abstractions: An
Introduction to Computer Science Using Scheme, by Max Hailperin, Barbara Kaiser, and Karl Knight.
The information here currently
corresponds with versions 7.3 through 7.7 of MIT-Scheme; we will try to track new
versions of MIT-Scheme as they come out.
MIT-Scheme is an implementation of Scheme that is made freely
available by MIT. It includes a text-editing user interface, similar
to GNU emacs, that is known as edwin. (If you don't know what
"similar to GNU emacs" means, it means that the interface is likely to
be appreciated by experienced hackers, but be something of a hurdle
for new users.) MIT-Scheme can be obtained from the
web. Versions are available for Windows, OS/2, and various
versions of Linux and Unix with X Windows. So far we have only tested
MIT-Scheme with the software for our book under Linux and Windows NT.
We know that our graphics examples won't work under OS/2.
than that, we don't know of any reason why our book wouldn't work
equally well with MIT-Scheme on other systems. We'd like to hear of
any problems you encounter.
Libraries for use with MIT Scheme
There are two areas of the textbook for which a special library needs
to be loaded into MIT Scheme. One is the graphical images, introduced
in the application section of chapter 1 and also used in subsequent chapters.
The other is the object-oriented programming system, used in chapter
Each of these libraries can be downloaded from the web below.
Once you have one of the library files on your system, you can load it
into MIT Scheme using the
load procedure. For example,
you could evaluate
(load "fungraph") to load in the
fungraph library. If the
fungraph.scm file isn't in your
current directory (folder) you might need to specify a pathname, such
(load "/usr/local/scheme-libraries/fungraph") or
- This is the library for graphical images. In addition to the
features described in the textbook (most succinctly in the appendix),
there are a few extensions. Descriptions of those extensions and a
couple hints regarding usage are in a separate web page.
- This is the object-oriented programming system for use with
Names defined in both Concrete Abstractions and MIT-Scheme
There are a number of names that we define in Concrete Abstractions
that are already pre-defined in MIT-Scheme. The only real problem this
causes is that if you perform the definition from the book, you can't
expect the name to simultaneously have both the new value and the one
described in the MIT-Scheme documentation.
We list below the affected names, organized into categories and listed
within each category in their order of their appearance within the book:
- R4RS names noted as such in the text
- R4RS names not noted as such in the text
- Non-R4RS names with equivalent functionality under
MIT-Scheme and in the book
square (MIT Scheme 7.5 and later only)
- Non-R4RS names with different functionality under
MIT-Scheme than in the book
merge-sort (MIT Scheme 7.5 and later only)
Equivalence of #f and the empty list
As mentioned in the Appendix, the R4RS standard for Scheme
allows Scheme implementations to have a single value play the roles of
#f (the false value) and the empty list,
(). MIT-Scheme has chosen to do this. The result, as
mentioned in the Appendix, is that you will see
output wherever the book shows
#f. However, you should
continue to use
#f in your programs.
Starting in chapter 6, we use the
newline procedure to
break output into separate lines. Unfortunately, there are two
different conventions in use by different Scheme systems. One is to
newline at the start of each line of output,
while the other is to always use it at the end of each line. As a
result of this lack of standardization, wherever we positioned the
(newline) in our programs would result in output
that looked odd on some systems. We've tried in the textbook to make
choices that don't look too horrible on any system, with the result
that the output tends to look sub-optimal on every system. In
particular, there tends to be extra blank lines. If you are working
consistently within MIT-Scheme (or any other one system), feel free to
remove or reposition
(newline) as necessary to make the
output look best.
Chapter by chapter notes
- Chapter 1
The procedures for manipulating graphical images need to be loaded
from a library, as described above. Additionally, it is worth noting
that the various basic blocks, such as
neither pre-defined nor defined within the library. Instead, their
definitions are in a separate file.
- Chapter 9
Several sequence procedures in section 9.2 use the name
sequence for a parameter. (The procedures are
Unfortunately, MIT-Scheme (up through 7.4) has chosen to preempt this name, making it
a special keyword equivalent to
begin. Therefore, to
make these five procedure work under MIT-Scheme, you will need to
rename the parameter; for example, you could use
sequence. The same consideration applies to any
other procedures you write: don't use the name
The preceding applies to MIT Scheme 7.3 and 7.4. In MIT Scheme 7.5
it is possible to use
sequence as a parameter name in a
lambda expression, as we do in section 9.2.
For the application section, we have a
MIT-Scheme-specific version of the
- Chapter 11
Although you could use the SLIM simulator from the application section
to work through the earlier sections of this chapter under MIT-Scheme,
you'd be better off using SLIME.
- Chapter 14
You will need to load a library file into MIT-Scheme to
get the object-oriented programming system, as described above.
- Chapter 15
MIT-Scheme cannot be used for this chapter, since this chapter doesn't
use the Scheme programming language. You will need to use a Java 1.1 system instead.
For more information, see the parent web page, or contact Max Hailperin:
Mathematics and Computer Science Department
Gustavus Adolphus College
800 W. College Avenue
St. Peter, MN 56082
Revision 1.7 as of 2003/06/01 12:25:54