Using Concrete Abstractions with DrScheme 100
This web page provides information regarding the use of the DrScheme
implementation of Scheme with Concrete Abstractions: An
Introduction to Computer Science Using Scheme, by Max Hailperin, Barbara Kaiser, and Karl Knight.
The information here
corresponds with version 100 of DrScheme, which is no longer the
current version. See the parent web page for
information on the current version.
DrScheme is an implementation of Scheme, including a graphical user
environment, that is made freely available by Rice University. It can
from the web. Versions are available for Windows 95 and NT,
MacOS, and various versions of Linux and Unix with X Windows. So far
we have only tested it with the software for our book under Linux and
but we don't know of any reason why it wouldn't work
equally well on other systems. As far as we can tell, DrScheme seems
quite well suited for use with our book; we'd like to hear of any
problems you encounter. Be warned that DrScheme is quite
memory-hungry. If it is the only program you are running, 32MB of
memory suffices, but if you routinely run it together with other
programs, then you may want more memory.
Settings for DrScheme
DrScheme can be set to use any of several variants of the Scheme
language. This is controlled through the
Configure Language... option. The initial setting if you
don't change it is known as Beginner mode. This mode is too restrictive
to use with much of the Concrete Abstractions textbook. For full
compatibility with Concrete Abstractions, switch to MrEd Debug mode.
Libraries for use with DrScheme
There are two areas of the textbook for which a special library needs
to be loaded into DrScheme. 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
14. We are making available three libraries. One provides the
graphics only, one the object-oriented programming system only, and
the third provides all the functionality in a single combined
library. There is no harm in using this library throughout the entire
book, beyond the consumption of memory and loading time, but no
Each of the three libraries can be downloaded from the web below.
Once you have one of the library files on your system, you can load it
into DrScheme using the
Set Library To... option within
- This is the library for graphical images only. 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.
Note that we also have an alternative
version of the functional graphics package that is a DrScheme
"tool" rather than a "library". (See the web
page for that version for what this difference means.) The tool
version is easier to install in this release than in the last, and you
should give it serious consideration.
- This is the object-oriented programming system for use with
- This is the combined library, providing all the functionality of
the other two.
Names defined in both Concrete Abstractions and DrScheme
There are a number of names that we define in Concrete Abstractions
that are already pre-defined in DrScheme. 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 DrScheme documentation.
For each name,
the DrScheme definition remains available by prefixing the name with
#%. For example, if in chapter 7 you have defined
length to be your own procedure, you can still
use DrScheme's version using
#%length. Or, you can
return to the original definition of
length by using
(define length #%length)
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
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 DrScheme (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 6
This chapter first introduces interactive programs, which display
output and read input. See the note above regarding the positioning
Also, there is one review problem at the end of this chapter that asks
you to define a procedure with the name
time. This will
not be possible under DrScheme, since DrScheme reserves that name for a
special form for timing the evaluation of expressions. Use another
- Chapter 9
For the application section, we have a
DrScheme-specific version of the
- Chapter 10
Be warned that DrScheme has its own
read-eval-print-loop, which gives a
normal Scheme (as opposed to micro-Scheme or mini-Scheme) REPL. Thus,
if you fail to execute the definition from the book, you could be
fooled by DrScheme's loop into thinking that everything is working
fine. To guard against this, be on the lookout for the different
prompts; micro-Scheme and mini-Scheme both specifically identify
themselves in their prompts.
- Chapter 11
Although you could use the SLIM simulator from the application section
to work through the earlier sections of this chapter under DrScheme,
you'd be better off using SLIME.
- Chapter 14
You will need to load a library file into DrScheme to
get the object-oriented programming system, as described above.
- Chapter 15
DrScheme 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 1.2 as of 2002/12/05 15:04:27