Using DrScheme

How do I find general help for DrScheme?

The DrScheme manual is available by clicking on the Help button at the top right of DrScheme's window.

How do I run MrSpidey, DrScheme's program analyzer?

MrSpidey is distributed separately from the standard DrScheme distribution. Download MrSpidey from

http://www.cs.rice.edu/CS/PLT/packages/mrspidey/

What happened to the Analyze button?

Starting with version 51, DrScheme is distributed without the MrSpidey analysis tool. See the previous answer for information about obtaining MrSpidey.

How do I customize DrScheme?

The Edit menu contains a Preferences item that opens the preferences dialog.

How do I turn off parenthesis-flashing and the gray background behind expressions?

Use the Edit|Preferences menu item.

What are the key bindings in DrScheme?

Some basic key bindings are listed in the DrScheme manual, which is accessible via the Help button in DrScheme. A more complete set of key bindings is listed in the MrEd toolbox manual, which is optional documentation that can be downloaded.

Can I change the key bindings in DrScheme?

Technically, yes, but that requires in-depth information about the way that DrScheme is implemented. (The necessary information is part of the MrEd toolbox manual.) However, there is no simple way to adjust the keyboard mappings, other than to set the behavior of the delete key via the preferences dialog.

What do those yellow-and-black messages mean, and how do I get rid of them?

When the text in the definitions window is modified, DrScheme pessimistically assumes that some definition has been changed. In this case, expressions evaluated in the interaction window would use definitions that do not match those currently displayed in the definitions windows. A yellow-and-black message warns you about this potential inconsistency, and suggests that you resolve the inconsistency by clicking the Execute button.

The messages can be lessened via the preferences dialog.

Why can't I type in the interaction window before the the current prompt?

DrScheme does not allow previously evluated expressions in the interaction window to be edited. However, old expressions can be easily copied to the current prompt by typing ESC-P, or by typing ENTER while the caret is positioned at the end of an expression.

Is there a DrScheme compiler?

DrScheme is a compiler; each time an program is loaded or an expression is enetered into the read-eval-print loop, DrScheme compiles and then executes the program or expression.

PLT's mzc transforms Scheme programs into C programs and then uses a third-party C compiler to produce executable code. Under Windows, either Microsoft Visual C or gcc (a free compiled from Cygnus solutions) can be used as the C compiler. Under MacOS, CodeWarrior can be used. Under Unix, most compilers are supported.

For details, see the mzc documentation, available from:

http://www.cs.rice.edu/CS/PLT/packages/doc/

Can I produce stand-alone executables from Scheme code?

The mzc compiler can be used to produce stand-alone executables if DrScheme's graphics toolbox is not used. See the mzc documentation for more information.

Where are DrScheme preferences stored in Windows?

If the USERDRIVE and USERPATH environment variables are defined, the preferences are put in %USERDRIVE%\%USERPATH%\mred.pre if that directory exists. Otherwise, preferences are written to the same directory as DrScheme.exe.

Windows NT: When DrScheme is launched under Windows NT and USERDRIVE and USERPATH are not set, NT automatically sets the variables to indicate the root directory of the main disk. Therefore, when USERDRIVE and USERPATH are not set in NT, the preferences file mred.pre is saved in the root directory.

Can files saved in DrScheme be transferred between platforms?

DrScheme saves files in two formats: text and multimedia.

The text format is the usual platform-specific text format. Tools for moving files between platforms typically support a ``text'' transfer mode that adjusts newlines and carriage returns in the test as appropriate.

The multimedia format, used for saving files that contain pictures or formatted text, is platform-indepdendent. Although no other program is able to read DrScheme's special format, a multimedia-format file can be moved between different platforms (in ``binary'' mode) and DrScheme will read it correctly on the destination platform.