Section 0

Getting Started with DrScheme

This DrScheme Companion runs in parallel to How to Design Programs. It explains how to use DrScheme as you work through the book, providing details about Scheme or DrScheme only as they become important.

If you have a question that is not answered along the way, the appendix contains a list of ``Frequently Asked Questions'' and answers. If the ``FAQ'' does not contain an answer to your question, consult one of the other sources of help:

Acknowledgements:    The screen snapshots in this book imitate images created by Mark Leone.

0.1  Getting DrScheme

DrScheme is available (for free) via

0.2  Installing and Starting DrScheme

0.2.1  Windows (95 and up)

DrScheme runs under Windows 95 and up. DrScheme does not run with earlier versions of Windows, such as Windows 3.1 (even with the Win32s extension).

The Windows version of DrScheme is distributed in the installer program plt.exe. (The floppy-disk distribution consists of plt.exe on disk 1, plt.w02 on disk 2, etc.) Running the installer unpacks the DrScheme files to your hard drive, usually in a subdirectory named plt within your main Program Files directory, and sets up shortcuts for the DrScheme programs under the Start menu.

The installer also creates uninstall.exe in the installed plt directory. Run uninstall.exe to uninstall DrScheme before installing a new version. Old versions of the uninstaller (before version 100) are not able to remove all the files, so you must manually delete the old plt directory after running uninstall.exe.

After installing DrScheme, run it via the Start menu by selecting Start --> Programs --> PLT Scheme --> DrScheme.

0.2.2  Macintosh

DrScheme runs on PowerPC Macintoshes with Mac OS 9 or Mac OS X.

The Macintosh version of DrScheme is distributed as StuffIt files. Unpack the StuffIt archive with StuffIt or StuffIt Expander to get a plt folder. The DrScheme application is located directly in the plt folder. (In Mac OS 9, DrScheme actually launches the MrEd application to run DrScheme.)

0.2.3  Unix/X Window System

Precompiled DrScheme executables are distributed for some Unix architectures, notably Linux. Installation instructions should be downloaded at the same time as the distribution archive. (The final page for downloading an X distribution includes a link for the installation instructions.)

Run DrScheme by executing plt/bin/drscheme.

0.3  Preparing DrScheme

IMPORTANT: DrScheme provides several languages that customize DrScheme for different levels of learning. Initially, you will use DrScheme's Beginning Student language. Beginning Student is the default; if it is changed, you can restore the language setting as follows:

  1. Select Choose Language... from the Languages menu. A dialog box appears with a choice control (a.k.a. ``pop-up menu'') at the top.

  2. Choose the Beginning Student langauge from the hierarchical choice list. You may have to click the How to Design Programs arrow to reveal the Beginning Student choice. After choosing Beginning Student, click OK.

  3. Click the Execute button. After clicking Execute, the lower window indicates that the current language is Beginning Student.

You need to set the language level only once until you change languages. When you quit and restart DrScheme, the langauge setting is preserved.

The Beginning Student language level is used for Part I, Intermezzo 1, and Part II. Starting with Intermezzo 2, switch to Beginning Student with List Abbreviations. Starting with Intermezzo 3, switch to Intermediate Student. Starting with Intermezzo 4, switch to Intermediate Student with lambda. Finally, starting with Part VII, switch to Advanced Student.