To use general topics, the LispWorks application must define one or more subclasses of
. If an application supports only a single type of document, it will typically require only one topic class. If several different types of document are supported, it may be convenient to define a different topic class for each type of document.
If the application uses general topics, it should define a method on the
generic function, specializing on the application's server class.
The generic function
returns a list of the available general topics on a given server. A suitable method specializing on the server class should be defined. Dispatching topics should not be returned, as they are handled automatically by LispWorks. If you do not provide a
method, the default method returns
, which prevents the DDE server from responding to the topics request.