6.4.3 Guidelines for use of the editor source code
Some care is needed when working with the supplied editor source code, to ensure that you do not compromise the IDE or introduce a dependancy on a particular release of LispWorks.
In particular please note:
The editor source code may not match the compiled code in the LispWorks image exactly, for example if editor patches have been loaded.
Modifications to the EDITOR package definition are not allowed.
Redefining existing definitions is not recommended. It is better to define a new command to do what you want. If you find a bug or have a useful extension to an existing definition then please let us know.
Do not rely on the expansion of exported macros.
If you use any internal (that is, not exported) EDITOR symbols, please tell us, so we can consider how to support your requirements. In addition, some internal macros have been removed from the LispWorks image and these should not be used.
LispWorks Editor User Guide (Windows version) - 22 Dec 2009